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A Field Guide for Site Identification andInterpretation for the Southwest Portionof the Prince George Forest Region
Land ManagementHandbook NUMBER 24
1993
Province ofBritish ColumbiaMinistry ofForests
A Field Guide for Site Identification and Interpretation for the Southwest Portion of
the Prince George Forest Region
C. DeLong , D. Tanner, and M.J. Jull
Ministry of Forests Research Program
1993
Canadian Cataloguing in Publication Data DeLong, C.
A field guide for site indentification and interpretation for the southwest portion of the Prince George Forest Region
(Land management handbook. ISSN 0224-1622 ; no. 24)
Includes bibliographical references p. ISBN 0-7718-9322-1
1 . Bioclimatology - British Columbia. 2. Biogeography - British Columbia. 3. Forest ecology - British Columbia. 4. Forest management - British Columbia. 5. Prince George Forest Region (B.C.) I. Tanner, D. II. Jull, M. J. Ill. British Columbia. Ministry of Forests, Research Branch. IV. Title. V. Series.
QH541.5.F6.D44 1993 581.5'2642'09711 C93-092023-6
Prepared by Craig DeLong, David Tanner and Mike Jull British Columbia Ministry of Forests Forest Sciences Section 1011 - 4th Avenue Prince George, B.C.��� V2L 3H9
© 1993 Province of British Columbia Published by the Research Branch Ministry of Forests 31 Bastion Square Victoria, B.C. V8W�3E7
Copies of this and other Ministry of Forests titles are available from Crown Publications Inc., 546 Yates Street, Victoria, B.C. V8W 1K8.
ACKNOWLEDGEMENTS
The number of people who have contributed to the evolution of the classification system and the interpretations developed for the units in the classification are too numerous to acknowledge. An attempt has been made to acknowledge those who have contributed to the text contained in this specific document.
In addition to Craig DeLong, the senior author, Wayne Blashill, Bob Faye, Graeme Hope, Lori Jang, Stephen Jenvey, Andy MacKinnon, Ian McIver, Angus McLeod, Del Meidinger, Ken Simonar and Duncan Williams assisted in field data collection in the Prince George Region. For the SBSdk, SBPSmc and most units of the SBSmc2, data collection was done primarily by Prince Rupert Forest Region research staff. For the SBSdw2 and some units of the SBSmc2, data collection was done primarily by Cariboo Forest Region research staff. George Argus (Salicaceae), Adolf Ceska (Cyperaceae), and George Douglas identified or verified identification of vascular plant specimens. Frank Boas and Judy Godfrey (Hepaticae) identified the bryophytes and Trevor Goward identified the lichens.
This field guide is based on a correlated classification of the ecological plot data made possible by the Correlation Program coordinated by Del Meidinger. Tracy Fleming, Shirley Mah, Carmen Cadrin, and Karen Yearsley are thanked for data analysis of relevance to this guide. Data used to assist in developing the wildlife tables were compiled by Kevin Hooge.
For the introductory portions of the guide, Allen Banner, Tom Braumandl, Mike Curran, Del Meidinger and Jim Pojar each provided text that was only adapted to form most of Sections 1 and 2 and portions of Section 3. Paul Sanborn contributed the soils, geology and landforms sections and Linda Murray the wildlife sections for the biogeoclimatic unit summary pages. Ruth Lloyd provided ideas and text that went into the wildlife section (Section 5.3).
The introductory sections were reviewed by Del Meidinger, Brian Robinson of Industrial Forestry Service, and Heather Strongitharm. The site unit descriptions, edatopic grids, vegetation tables, and site identification keys were reviewed by Allan Banner, Ray Coupé, Del Meidinger, and Ordell Steen. Much discussion with many wise operational and research personnel led to the development of many of the interpretations. Lorne Bedford, Mike Bruhm, Heather Dawson, Rick Fahlman, Les Herring, Dave Preslee, and Brian Robinson were most helpful in providing thorough review of the forestry interpretation portions of the guide. The wildlife sections were reviewed by Dave King, Chris Ritchie, and Glen Watts. Bob Hodgkinson, Stuart Taylor, and Richard Reich reviewed the forest health information.
Graphics for edatopic grids, vegetation tables, site preparation keys, and the stand structure key were prepared by staff of T. D. Mock and Associates. The map displaying biogeoclimatic units was prepared by staff of Shearwater Mapping Incorporated. All other graphics were prepared by the Research Branch, Communications and Extension Services Section, or by the authors. Final publication was coordinated by the Communications Section. Publication costs were supported by the Prince George Regional Silviculture Section.
iii
TABLE OF CONTENTS
ACKNOWLEDGEMENTS ................................... iii
1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Objectives/Scope ................................... 1 1.2 Other Sources of Information . . . . . . . . . . . . . . . . . . . . . . . 2 1.3 Guide Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.4 Training Courses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
THE BIOGEOCLIMATIC ECOSYSTEM CLASSIFICATION (BEC) SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1 Classification System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2 Zonal (Climatic) Classification ...................... 5 2.3 Site Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
PROCEDURES FOR SITE DESCRIPTION, IDENTIFICATION, MAPPING, AND INTERPRETATION ..................... 8 3.1 Introduction ...................................... 8 3.2 Identifying Biogeoclimatic Units (Subzone/Variant) . . . . . 9 3.3 Identifying Site Units ............................... 9 3.4 Site Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.4.1 Hand texturing guides ........................ 12 3.5 Identifying Seral Ecosystems ........................ 23 3.6 Mapping Site Units . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.6.1 Producing a preliminary legend 3.6.2 Typing aerial photographs . . . . . . . . . . . . . . . . . . . . . 3.6.3 Field surveys (ground truthing) . . . . . . . . . . . . . . . . . 24
3.6.5 Producing the final map ....................... 3.7 Management Interpretations ........................ 25
3.7.1 Direct interpretations . . . . . . . . . . . . . . . . . . . . . . . . . 25
2
3
24
3.6.4 Refining and labelling map polygons . . . . . . . . . . . . . 24 24
3.7.2 Indirect or general interpretations . . . . . . . . . . . . . . .
BIOGEOCLIMATIC AND SITE UNIT DESCRIPTIONS AND INTERPRETATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 4.1 Dry Cool Sub-Boreal Spruce Subzone . . . . . . . . . . . . . . . . . 31
4.2 Blackwater Dry Warm Sub-Boreal Spruce Variant . . . . . . . 63 4.3 Stuart Dry Warm Sub-Boreal Spruce Variant . . . . . . . . . . . 92 4.4 Babine Moist Cold Sub-Boreal Spruce Variant . . . . . . . . . . 119
Kluskus Moist Cold Sub-Boreal Spruce Variant . . . . . . . . . . 150 4.6 Mossvale Moist Cool Sub-Boreal Spruce . . . . . . . . . . . . . . . 174
Moist Cold Sub-Boreal Pine - Spruce Subzone . . . . . . . . . . . 202
Subalpine Fir Variant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222
26
4
4.5
4.7 4.8 Nechako Moist Very Cold Engelmann Spruce -
5 INDIRECT AND GENERAL INTERPRETATIONS . . . . . . . . . . . 237 5.1 Silvicultural Systems Interpretations . . . . . . . . . . . . . . . . . 237
5.1.1 Steps for choosing an appropriate silvicultural
5.1.2 Collection of stand data . . . 5.1.3 General terminology . . . . . . 5.1.4 Descriptions of reproduction methods . . . . . . . . . . . . . 249
5.1.4.1 Clearcutting methods . . . . . . . . . . . . . . . . 249
system . . . . . . . . . . . . . . . . . . . . . . . . . . . 238
V
23
240 248
5.1.4.2 Seed-tree methods . . . . . . . . . . . . . . . . . . 251 5.1.4.3 Shelterwood methods . . . . . . . . . . . . . . . . 251 5.1.4.4 Selection methods . . . . . . . . . . . . . . . . . . 252
5.2 Site Preparation Keys .............................. 254 . . . . . . . . . . . . . . . 263
5.3 Wildlife Interpretations ............................... 264 5.3.1 Habitat characteristics for species of management
concern .................................... 268
New names for biogeoclimatic and site units in the southwest portion of the Prince George Forest Region .................................... 282
5.2.1 Reducing slash during harvesting
APPENDIX 1 .
APPENDIX 2 . Selected references for ecosystem description and interpretation, soils, vegetation, wildlife, and silvicultural systems for the southwest portion of the Prince George Forest Region . . . . . . . . . . . . . . . . . . . 285
LITERATURE CITED ...................................... 288
TABLES
1. 6
2. Site and soil factors to be collected . . . . . . . . . . . . . . . . . . . . . . . . 11
3. Hand texturing guide .................................. 13
System of naming and coding interior biogeoclimatic units . . . . . .
4. Properties of soil separates .............................. 13
5. Identification of upland humus forms ...................... 17
6. Definitions of terms used in the identification of relative soil moisture regimes ..................................... 18
7 . Sections and page numbers of biogeoclimatic unit subsections . . . 21
8.
9.
Summary of climate data for biogeoclimatic units . . . . . . . . . . . . .
Some important wildlife species that use biogeoclimatic units in the West Central guide area .............................
Potential silvicultural system options based on effective stand structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
. . . 244
28
29
10.
11 .
12.
Comparison of objectives of silvicultural system prescriptions
Comparison of residual stand structures retained after initial partial cutting stand entry .............................. 246
Soil grouping for all combinations of coarse fragment content and soil texture .......................................... 254
Figure and page numbers for site preparation keys . . . . . . . . . . . 255
13.
14.
vi
15.
16.
17.
18.
Fuel consumption for different prescribed burning severities . . . . 261
Bird species groups considered in the wildlife tables . . . . . . . . . . . 270
Table and page numbers for wildlife tables . . . . . . . . . . . . . . . . . . 271
Information for wildlife species of management concern for dry lodgepole pine site groups ............................... 274
Information for wildlife species of management concern for dry Douglas-fir site groups ................................. 275
Information for wildlife species of management concern for moist Douglas-fir site groups ................................. 276
Information for wildlife species of management concern for moist hybrid white spruce site groups .......................... 277
Information for wildlife species of management concern for wet hybrid white spruce site groups .......................... 278
Information for wildlife species of management concern for very wet hybrid white spruce - subalpine fir site groups . . . . . . . . . . . . 279
Information for wildlife species of management concern for moist subalpine fir site groups ................................ 280
Information for wildlife species of management concern for very wet black spruce site groups ............................. 281
19.
20.
21.
22.
23.
24.
25.
FIGURES
Biogeoclimatic units of the southwest portion of the Prince George Forest Region ........................................ 1
Hierarchical relationship between climatic-level (zonal) and site- level classifications .................................... 4
Typical sequence of combinations of relative soil moisture and soil nutrient regime within the guide area ..................... 7
4. Slope position (mesoslope) .............................. 12
5. Soil texturing key ..................................... 14
6 . A key to the identification of relative soil moisture regimes . . . . . 19
7 . Key for estimating relative soil nutrient regimes . . . . . . . . . . . . . 20
8. Zonal vegetation of biogeoclimatic units within and adjacent to area covered by the guide ...............................
Edatopic grid displaying site units in the SBSdk subzone . . . . . . .
1.
2.
3.
22
33 9.
vii
10 . SBSdk vegetation table ................................ 34
11 . Edatopic grid displaying site units in the SBSdw2 variant . . . . . . 65
12 . SBSdw2 vegetation table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
13 . Edatopic grid displaying site units in the SBSdw3 variant . . . . . . 94
14 . SBSdw3 vegetation table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
15 . Edatopic grid displaying site units in the SBSmc2 variant . . . . . . 121
16 . SBSmc2 vegetation table ............................... 122
17 . Edatopic grid displaying site units in the SBSmc3 variant . . . . . . 152
18 . SBSmc3 vegetation table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
19 . Edatopic grid displaying site units in the SBSmk1 variant . . . . . . 176
20 . SBSmk1 vegetation table ............................... 177
21 . Edatopic grid displaying site units in the SBPSmc subzone . . . . . 204
22 . SBPSmc vegetation table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
23 . Edatopic grid displaying site units in the ESSFmv1 variant . . . . . 223
24 . ESSFmv1 vegetation table .............................. 224
25 . Key for identification of stand structure type . . . . . . . . . . . . . . . . 239
26 . Site preparation key number 1 (wet sites) . . . . . . . . . . . . . . . . . . 256
27 . Site preparation key number 2 (moist sites) . . . . . . . . . . . . . . . . . 258
28 . Site preparation key number 3 (very wet sites) . . . . . . . . . . . . . . . 259
29 . Site preparation key number 4 (high-elevation sites) . . . . . . . . . . 260
30 . Example of forest structure associated with seral stages . . . . . . . 265
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1 INTRODUCTION
1.1 Objectives/Scope
This guide presents site identification and interpretation information for forest ecosystems of the southwest portion of the Prince George Forest Region (Figure 1).
FIGURE 1. Biogeoclimatic units of the southwest portion of the Prince George Forest Region.
The classification system used follows the Biogeoclimatic Ecosystem Classification (BEC) developed for the province by the B.C. Ministry of Forests (Pojar et al. 1987). The principles have evolved from the work of V.J. Krajina (1965,1969) and are described in Chapter 2. The objectives of this classification are:
• to provide a framework for organizing ecological information and
• to promote further understanding of identified ecosystems and the
• to supply resource managers with a common language to describe forest
• to improve the user's ability to prescribe and monitor treatment regimes
management experience about ecosystems;
relationships among them;
sites; and
on a site-specific (ecosystem) basis.
The guide has two main goals: • to assist the user in classifying sample sites in the field; and • to provide interpretations for these site units that will assist the user
in preparing management prescriptions.
This version of the guide results from the recent completion of an inter- regional correlation of the BEC system. The correlation project was completed to ensure the consistency and quality of the ecological information base across the province. This guide replaces the following guides for use in the Prince George Forest Region: DeLong et al. (1984) for the SBSmk1 (previously SBSe2); DeLong et al. (1984) for the SBSdw3 (previously SBSk3); DeLong et al. (1985) for the SBSmc3 (previously SBSi); DeLong et al. (1987) for the SBSdw2 (previously SBSk2); and Lewis et al. (1986) for the SBSdk (previously SBSd), SBSmc2 (previously SBSe1), and SBPSmc (previously SBSa2). Appendix 1 presents the correlation between the previous site and biogeoclimatic units and this classification.
All sites slated for harvest are required by law under the Silviculture Regulations (1988) to be classified according to the biogeoclimatic classification system.
1.2 Other Sources of Information
Numerous reports on vegetation, soils, wildlife, and ecosystem description and classification exist for the southwest portion of the Prince George Forest Region and adjoining area. A list of these references can be found in Appendix 2.
A more comprehensive discussion of the BEC system and more complete descriptions of units at broader levels within the hierarchical structure, particularly site associations and site groups, will be available in a series of biogeoclimatic zone reports to be published by the B.C. Ministry of Forests, Research Branch. Information at the biogeoclimatic zone level is available in Ecosystems of British Columbia (Meidinger and Pojar 1991).
An excellent reference for plant identification is Plants of Northern British Columbia (MacKinnon et al. 1992). Page numbers for plants used in site unit identification keys found in each biogeoclimatic unit subsection refer to this publication. It is available at major book stores or from Lone Pine Publishing in Edmonton, Alberta.
2
1.3 Guide Contents
This guide consists of five chapters. Following the introduction is a brief discussion of the classification system (Chapter 2). Chapter 3 provides procedures for site description, identification, mapping, and interpretation. Chapter 4 contains information about the biogeoclimatic units described, tools for identification of biogeoclimatic and site units, descriptions of the site units, and direct management interpretations for the identified site units. Chapter 5 presents indirect interpretations for silviculture systems and site preparation, and direct interpretation tables for some wildlife species of management concern.
Biogeoclimatic unit maps (1:250 000 scale) to be used in conjunction with this guide are available from each Ministry of Forests district office or from the Forest Sciences Section, Prince George Forest Region.
The classification is based on approximately 1000 plots located in the southwest portion of the Prince George Forest Region and in shared biogeoclimatic units in the Prince Rupert and Cariboo Forest Regions. The plots are generally well distributed geographically (proportional to the size of the biogeoclimatic unit) except in units with difficult access, such as those within the ESSF zone. Most site units are characterized by at least five plots, although certain less common sites (ie., very dry and wet sites) are typically characterized by a smaller number of plots.
1.4 Training Courses
It is assumed that the user of this guide is familiar with the basic concepts and methods of site, soil, and vegetation evaluation and has completed the training programs offered by the Forest Sciences Section. These courses are offered annually in various locations within the region. For information about such training courses, please contact the Forest Sciences Section, Prince George Forest Region.
2 THE BIOGEOCLIMATIC ECOSYSTEM CLASSIFICATION (BEC)
This section briefly describes the biogeoclimatic classification system. For a more complete description refer to Ecosystems of British Columbia (Meidinger and Pojar 1991) or Biogeoclimatic Ecosystem Classification for British Columbia (Pojar et al. 1987).
2.1 Classification System
The BEC system is a hierarchical classification scheme that combines three classifications: climatic (or zonal), vegetation, and site. For practical purposes, users need only be concerned with the zonal and site classifications (Figure 2). The information presented in this guide will allow the user to apply BEC in the field.
3
Vegetation
classification
Zonal
classification
plant class
plant order
plant alliance
plant
association
plant
subassociation
Climax and zonal concepts
Climax and
ecological equivalence
concepts
Site
classification
site association
site series
site types
biogeoclimatic
formation
biogeoclimatic
region
biogeoclimatic
zone
biogeoclimatic
subzone
biogeoclimatic
variant
FIGURE 2. Hierarchical relationship between climatic-level (zonal) and site- level classifications (taken from Pojar et al. 1987). The highlighted classifications are described in this guide.
4
2.2 Zonal (Climatic) Classification
Biogeoclimatic units are the result of zonal (climatic) classification and they represent groups of ecosystems under the influence of the same regional climate. There is a hierarchy of climatic units, with the biogeoclimatic subzone as the basic unit. Subzones are grouped into zones, and divided into variants.
Data from long- and short-term stations have been used to help characterize subzones. Because climate stations are not well distributed within and among subzones, climax vegetation on zonal sites 1 must serve as an indicator of the long-term climate of the area.
Each biogeoclimatic subzone has a distinct climax (or near-climax) plant association on zonal sites. Zonal sites have deep, broadly loamy soils and occupy midslope positions with mesic moisture regimes. The zonal climax vegetation is thought to best reflect the regional climatic conditions of the subzone.
Ecosystems within a subzone are influenced by this one type of regional climate. Edaphic (soil) and topographic conditions influence the climax vegetation of sites either drier or wetter than the zonal condition. Thus, subzones have distinctive sequences of related ecosystems ranging from dry to wet sites. For example, in a moist cool subzone of the Sub-Boreal Spruce (SBS) zone, zonal sites are dominated by a lodgepole pine and hybrid white spruce canopy with a diverse, moderately well-developed understory of shrubs and herbs; dry sites have pure lodgepole pine canopies with an understory dominated by feathermoss and lichens; and wet sites in the same subzone (climate) have hybrid white spruce overstories with an understory dominated by devil's club and oak fern.
The biogeoclimatic variant was defined because subzones contain considerable geographic variation. Variants reflect further differences in regional climate and are generally recognized for areas that are slightly drier, wetter, snowier, warmer, or colder than other areas in the subzone. For example, the Blackwater Dry Warm variant (SBSdw2) of the SBS is warmer and has a longer frost-free period than the Stuart Dry Warm variant (SBSdw3) of the SBS. These climatic differences result in corresponding differences in vegetation, soil, and ecosystem productivity. The differences in vegetation are evident as distinct zonal climax plant subassociations.
Subzones with similar climatic characteristics and zonal ecosystems are grouped into biogeoclimatic zones. A zone is a large geographic area with a broadly similar type of climate. A zone has typical patterns of vegetation and associated similarities in nutrient cycling and soil climate. Zones also have one or more typical zonal climax species of tree, shrub, herb, or moss.
Zones are usually named after one or more of the dominant climax species in zonal ecosystems and a geographic or climatic modifier (eg., Sub-Boreal Spruce zone). Zones are given a two- to four-letter code that corresponds to the name. For example, the Sub-Boreal Spruce zone code is SBS.
Subzone names are derived from classes of relative precipitation and temperature. Subzone codes correspond to the climatic modifiers (Table 1). For
1 Zonal sites are sites that best reflect the mesoclimate or regional climate of an area.
5
example, the SBSdk refers to the dry cool (dk) subzone of the Sub-Boreal Spruce (SBS) zone. Variants are named by geographic area and ordered by number from south to north and from west to east. Hence, the SBSdw2 variant is more southerly than the SBSdw3 variant.
TABLE 1. System of naming and coding interior biogeoclimatic units
ZONE ab
a = precipitation regime b = temperature regime
x = very dry h = hot
d = dry w = warm m = moist m = mild w = wet k = cool v = very wet c = cold
v = very cold
2.3 Site Classification
Site series are the most commonly used units of site classification (Figure 2). Site series occur within a biogeoclimatic subzone or variant. They are defined by using late seral or climax vegetation and result in site units having similar environmental properties and vegetation. The potential vegetation and selected environmental properties are used in this guide to characterize site series.
Each biogeoclimatic unit has a characteristic sequence of site series according to soil moisture regime (SMR) and, to a lesser degree, soil nutrient regime (SNR). 2 Soil moisture regime is a relative scale of "available water" for plant growth within the climate of the biogeoclimatic unit. An eight-class scale is used; it ranges from 0 or very xeric (bare rock) to 7 or subhydric (water tables at or near the surface year round). Soil nutrient regime is a relative scale of "available nutrients" for plant growth. A five-class scale ranging from A (very poor) to E (very rich) is used. An example of where sites with different combinations of SMR and SNR would occur on a typical landscape within the guide area is presented in Figure 3.
Common names of one to four species are used to name site series, and tree species codes are usually substituted to shorten the name (eg., Sxw - Devil's club site series).
Similar plant communities can occur in different biogeoclimatic units, but the relative moisture regime that they represent may differ between subzones. These communities belong to the same grouping of site series that is collectively called a site association. 3 For example:
SBSvk/Sxw - Devil's club site series# = SBSvk/0l SBSmk1/Sxw - Devil's club site series# = SBSmk1/08 SBSwk3/Sxw - Devil's club site series# = SBSwk3/06
2 The site identification section (Section 3.4) contains soil moisture and soil nutrient regime identification information.
Site associations are not used in the classification presented in this manual. They are defined in Pojar et al. (1987).
3
6
MOISTURE REGIME
0 - very xeric 4 - mesic
1 -xeric 5 - subhygric
2 - subxeric 6 - hygric
3 - submesic 7 - subhydric
NUTRIENT REGIME 1
A - very poor
B - poor
C - medium
D - rich
E - very rich
1 Large range in nutrient regime depending on compactness of till which will affect effective rooting depth.
FIGURE 3. Typical sequence of combinations of relative soil nutrient regime found on the landscapes within the guide area.
All three of these site series belong to the same site association, so their climax vegetation is similar, but their occurrence in the landscape, site conditions, and seral vegetation patterns may differ among the three biogeoclimatic units.
Each site series is given a two-digit numeric code that relates to its position on the relative moisture and nutrient scales. Within a biogeoclimatic unit, the forested units are numbered as follows: the 01 site series is the zonal or mesic site, with the rest ranked from driest (02) to wettest (generally 09 to 12) and, secondarily, poorest to richest. Non-forested units use higher-order numbers to keep them distinct from the forested units. For example, grasslands are assigned numbers from 80 to 90.
Management interpretations are often made directly at the site series level. In some cases, however, interpretations are most efficiently dealt with at broader or finer levels of the classification, such as those less sensitive to site-level differences (eg., wildlife) or those affected more by variations in site and soil conditions than by climate or vegetation (eg., site preparation) (see Section 5).
3 PROCEDURES FOR SITE DESCRIPTION, IDENTIFICATION, MAPPING, AND INTERPRETATION
3.1 Introduction
Ecological site identification consists of collecting accurate site, soil, and vegetation information, and then using the various tools and descriptive material presented in the guide to identify the site unit that best fits the information collected. The development of an appropriate management prescription depends on accurate site description and other site-specific data (eg., slope gradient, soil texture), as well as correct site unit identification. Combining site identification with the collection of site, soil, and vegetation data provides the most complete ecological description of the site.
The guide user must understand that there is much more natural variability in the forests than is portrayed in this field guide; thus, not every ecosystem encountered will be easily "pigeonholed" into an existing classification unit. The "cookbook" approach to site identification and interpretation is not encouraged. This field guide is intended to promote ecological thinking and a better understanding of forest ecosystems.
The guide assumes that the user has a basic knowledge of ecosystem classification concepts, soils description, and plant identification. Field courses coordinated by regional Forest Sciences staff are held in most forest districts (depending on demand) in the Prince George Forest Region every summer. Pre- Harvest Silvicultural Prescription (PHSP) and silviculture survey courses, which have an ecological classification component, are also held annually. Regional Forest Sciences staff is available to assist with problems associated with field descriptions, identification, and management interpretations. Once on-site information has been gathered, a site can be identified using the step- by-step procedures outlined in the Site Identification section (Section 3.4). The two sections that follow provide a complete description of tools for biogeoclimatic and site unit identification. Information for mapping site units
8
and using the interpretations portions of the guide are discussed in Sections 3.6 and 3.7, respectively.
3.2 Identifying Biogeoclimatic Units (Subzone/Variant)
The following is a list of the tools available for assisting the user in identifying and describing biogeoclimatic units.
Biogeoclimatic maps: Available at a scale of 1:250 000 from the regional Forest Sciences Section or from district offices, these maps provide a relatively detailed portrayal of geographic distribution of the biogeoclimatic units. This information will also be available in digital format within the inventory data base so that it can be accessed in a variety of ways using Geographic Information System (GIS) capabilities. The biogeoclimatic map should be referred to before leaving the office, but should not be relied on totally, especially if the area is near biogeoclimatic unit boundaries or in complex, mountainous terrain.
Biogeoclimatic/Vegetation summary table: This table displays important vegetative differences between the biogeoclimatic units described as well as for bordering units not described in the guide. This table compares vegetation that is found on zonal sites (refer to Section 2.2). Once a zonal site has been identified, this table can be used either to identify or to reaffirm the identification of a biogeoclimatic unit.
Biogeoclimatic unit summary page: This page, located at the front of each biogeoclimatic unit subsection, contains a brief summary of geographic location, elevation range, climate, vegetation features that assist in distinguishing between adjoining biogeoclimatic units, soils, forests, and wildlife. The distinguishing features, location, and elevation range information can assist in the identification of a biogeoclimatic unit. The remainder of the information is useful as background material in documents related to the particular biogeoclimatic unit.
3.3 Identifying Site Units
The following is a list of the tools available for assisting the user in identifying site units.
Edatopic grid: The edatopic grid displays how the site series relate to each other along the relative gradients of moisture and nutrient regime. Once relative moisture and nutrient regimes are determined (see Section 3.4), the unit(s) generally associated with that moisture and nutrient regime can be identified from the grid.
9
Vegetation table: This table indicates the prominence of widespread diagnostic species by site series for each biogeoclimatic unit. Prominence values are derived by multiplying the square root of the constancy by mean cover. For example, when a species is present in 100% of sample plots (ie., constancy = 100) and has a mean cover of 5%, the prominence equals 50. Five prominence value classes are displayed by different-sized bars within the tables.
Prominence Value Prominence Class Schematic
0 - 4 0
5 - 15 1
16 - 50 2
51 - 100 3
101 - 200 4
201+ 5
In general, the vegetation tables contain species that are useful in differentiating between site units. The actual abundance of plant species on any given site depends on several factors, including the successional status of the site and the type and degree of disturbance that initiated succession. The table values are derived from plots in mature forests (80 years or older). These tables should not be used in seral (ie., early successional) stands that do not have a closed canopy (see Section 3.5). A possible solution is to find a mature stand adjacent to the seral stand, but the user must be fairly certain that this stand represents the same ecological unit as the site being assessed (eg., same slope position and soil texture).
Site series key: The dichotomous key uses a series of paired statements containing a combination of site, soil, and vegetation features to direct the user to a site series identification. Since the lead statements often refer to the tree canopy and any understory vegetation comments relate to mature sites, the keys work best on sites that have achieved crown closure. When attempting to use the keys on disturbed sites, the user must have some knowledge of the canopy dominance prior to disturbance and must not rely on the understory vegetation features described in the key. Alternatively, an adjacent mature stand could be used, though the user must be fairly certain that the stand represents the same ecological unit as the site being assessed (eg., same slope position and soil texture).
Site series summary page: For each site series there is a one-page summary of vegetation, site, and soil features. The vegetation list contains species that are found consistently (constancy) and develop reasonable cover (>l%). They are listed in order of constancy, and then in order of percent cover within the same level of constancy. Species in square brackets do not occur consistently, but when they do occur they have high cover. Three plants that generally characterize the unit are illustrated along the left-hand margin. For each site and soil feature, the range in conditions encountered during BEC sampling is indicated. Note that the range indicated may not express the true range of variability that may be encountered. Soil texture classes refer to those displayed on the soil texture triangle in Figure 5. Features preceded by an asterisk (*) are ones that can generally be relied on to differentiate or characterize the site.
10
3.4 Site Identification
This section outlines a step-by-step procedure to identify a site series. This procedure should be used until the user becomes intimately familiar with the site identification process and the site units in his or her area of operation.
Step 1
Locate an area for your assessment that appears to be representative of the unit being sampled, and is as homogeneous in plant cover and overstory canopy condition as possible. Avoid locating the sample area on sites that have recently received significant natural or artificial disturbance (eg., landings).
Step 2
Determine and record site and soil information important for site identification and the prescription process. Table 2 lists some of the more important site and soil factors to be collected. (Note that more detailed site and soil information may be required for certain purposes.) Tools that will help you assess some of the factors include mesoslope position (Figure 4), soil texture (Section 3.4. 1), and humus form (Table 5).
TABLE 2. Site and soil factors to be collected
Factor Definition
Slope gradient (%):
Aspect ( ° ) : - the compass direction a slope is facing.
Slope position:
- measure of a slope's incline; equals vertical rise divided by horizontal distance (100% slope = 45° angle).
- relative position of sampling site within a catchment area (eg., between slope breaks affecting surface water flow; see Figure 4)
relative proportion of sand, silt, and clay; defined proportions comprising textural classes (see Section 3.4.1).
% by volume of mineral soil fragments greater than 2 mm in diameter.
subjective assessment indicating the greatest depth to which root systems of forest trees freely penetrate; depth at which rooting abundance classes drop to "few" (see Luttmerding et al. 1990).
depth to a soil layer or condition that severely restricts root penetration (eg., compact parent material or bedrock).
depth to area in soil profile from which water is seeping out; evidence of periodic seepage during the growing season may be indicated by gleying (orange-coloured mottles within a generally olive- to blue-coloured soil matrix).
depth of group of horizons located at the soil surface that have formed primarily from organic materials, and that may include mineral soil intermixed with organic material.
the quality of the humus layer classed into three main orders (mor, moder, mull) based on the rate at which decomposition occurs within the layer (Table 5).
Soil texture: -
Coarse fragments (%):
Effective rooting depth -
(cm):
-
Depth to a restricting layer (cm):
Depth to seepage water (gleying) (cm):
-
-
Humus depth (cm): -
Humus form: -
11
FIGURE 4. Slope position (mesoslope) (from Lloyd et al. 1990).
3.4.1 Hand texturing guides
Soil texture refers to the relative proportions of the sand, silt, and clay separates within a soil. These separates have their own distinctive properties of "feel", allowing one to estimate their proportions in a sample of soil by hand texturing. To obtain accurate results, texturing must be done with a sample that has the correct moisture content as described below. Both a table (Table 3) and a key procedure (Figure 5) are provided. The user should become familiar with both and use the procedure that feels most comfortable.
PROCEDURE FOR HAND TEXTURING USING TABLE 3
1. Crush a small handful of soil in the hand, and remove coarse fragments (particles greater than 2 mm in diameter).
Gradually add water to the soil and, with a soil knife or fingers, work it into a moist putty. The correct moisture content is important. If the putty flows with the force of gravity it is too wet. If it crumbles when rolled it is too dry. It should have the consistency of filler putty.
Determine stickiness of the soil putty by working it between the thumb and forefinger, pressing and then separating the digits. An estimate of clay content can be made in this way. (Clay limits below are approximate.)
non-sticky: Practically no soil material adheres to the thumb and forefinger (less than 10% clay). slightly sticky: Soil material adheres only to one of the digits and comes off the other rather cleanly. The soil does not stretch appreciably when digits are separated (10-25% clay). sticky: Soil material adheres to both digits and stretches slightly before breaking when digits are pulled apart (25-40% clay).
12
2.
3.
very sticky: Soil putty adheres strongly to both digits and stretches distinctly before breaking (greater than 40% clay).
Determine the graininess of the soil putty by rubbing it between thumb and forefinger. An estimate of sand content can be made in this way. (Sand limits below are approximate.)
non-grainy: Little or no graininess can be felt (less than 20% sand). slightly grainy: Some graininess is felt, but non-grainy material (silt and clay) is dominant (20-50% sand). grainy: Sand is felt as the dominant material. Some non-grainy material can be felt between sand grains (50-80% sand). very grainy: Sand is the only material felt. Little or no non-grainy material is present (> 80% sand).
After stickiness and graininess have been determined, use the texturing table as an approximate guide to the textural class of the soil. The textural triangle found in Figure 5 can be used for more accurately determining the textural class and it also displays the textural class used in the site unit descriptions.
4.
5.
TABLE 3. Hand texturing guide a
Non-grainy Slightly Grainy Very Grainy (<20% sand) Grainy (50-80% sand) (>80% sand)
(20-50% sand)
Very Sticky Silty Clay Clay Sandy Clay (>40% clay)
Sticky Silty Clay Clay Loam Sandy Clay (25-40% clay) Loam Loam
Slightly Sticky Silt Loam or Loamb Sandy Loam 10-25% clay) Silt
Non-sticky Loamy Sand (< l0% clay) or Sand
a
b Sand and clay limits are approximate. A loam is a textual class exhibiting physical properties intermediate between those of sand, silt, and clay.
TABLE 4. Properties of soil separates
Properties of Fine Fraction
Clay:
Silt:
- very hard when dry; feels smooth and is very sticky when wet; feels smooth
when placed between teeth.
- slightly hard to soft when dry; powder is floury when dry; feels slippery and
slightly sticky when wet; silt cannot be felt as grains between thumb and forefinger, but can be felt as a fine graininess when placed between teeth.
- loose grains when dry; very grainy when felt between thumb and forefinger;
non-sticky when wet. Sand:
13
Soil Texturing Key Taste Test** Moist Cast Test Graininess Test Moist Cast Test Taste Test (grittiness)
Worm Test (Organic Matter Test) Stickiness Test Soapiness Test Worm Test Stickiness Test
SAND S non-gritty non-sticky
worm: none (85-100% sand)
LOAMY SAND LS non to s.gritty non to s.sticky
worm: none ~ (70-90% sand
SANDY LOAM S L non to s. gritty non to s sticky worm variable,
none or >3 mm dia (45-80% sand)
FINE SANDY LOAM FSL* grity to v.gritty non to s.sticky
worm: none, or 3 mm dia (45-85% fine sand)
forms no cast (<10% clay)
v.weak cast (no handling) (<15% clay)
START
weak cast (careful handling)
(<20%) clay)
> 5 0 % sand grainy t o v.grainy
50% sand non-grainy to s.grainy
~
moderate cast (easily handled)
(20% clay)
moderate cast (easily handled) non to s.sticky
, ( < 3 0 % clay)
strong cast (v.easily handled)
sticky (30-40% clay)
SILT Si* v.gritty v.soapy
worm: none or >3 mm dia (0-20% sand)
SILT LOAM SiL* gritty to v.gritty soapy to v.soapy
worm: none, or 3 mm dia (0-50% sand)
LOAM L s.gritty to gritty s.soapy to soapy
worm: none, or may equal 3 mm dia (25-50% sand)
SILTY CLAY LOAM SiCL s.gritty to gritty s.soapy to soapy
worm: 3-1.5 mm dia (0-20% sand)
CLAY LOAM CL non-gritty to s.gritty non-soapy to s.soapy worm: 3-1.5 mm dia
(20-45% sand)
SANDY CLAY LOAM SCL non to s.gritty
s.sticky to sticky worm: 3 mm dia (45-80% sand)
SANDY CLAY sc non-gritty
sticky to v.sticky worm: 3-1.5 mm dia
(45-65% sand)
strong cast (v.easily handled)
(20-55% clay)
>30% organic matter 100
90
80
70
60
50
40
30
20
10
0 0 10 20 30 40 50 60 70 80 90 100
PERCENT SAND
* * For description of soil texturing tests, see page 16.
Fine
Moderately Fine
Medium
Moderately Coarse
Coarse
very strong cast (v.easily handled)
v.sticky (>40% clay)
SILTY CLAY SiC s.gritty to gritty s.soapy to soapy
worm: strong 1.5 mm dia (0-20% sand)
CLAY or C or HEAVY CLAY HC
non-gritty to s.gritty non-soapy to s.soapy
worm: strong; 1.5 mm dia (0-45% sand)
ORGANIC O (no texture)
* Silt feels slippery or soapy when wet; fine sand feels stiffer, like grinding compound or fine sand paper.
Key to Abbreviations Measurement Conversions s = slightly v = very dia = diameter
3.0 mm = 1/8" 1.5 mm = 1/16"
Fine Fraction (particle diameter) SAND ------------- (S) SILT --------------- (Si) CLAY ------------- (C) <.002 mm HEAVY CLAY - (HC) LOAM ------------ (L)
2 - .05 mm .05 - .002 mm
>60% Clay mix of Sand, Silt, and Clay
FIGURE 5. Soil texturing key (from Braumandl and Curran 1992).
DESCRIPTION OF SOIL TEXTURING TESTS
1. Organic matter test: Well-decomposed organic matter (humus) imparts silt-like properties to the soil. It feels floury when dry and slippery or spongy when moist, but not sticky and not plastic. However, when subjected to a taste test (see below), it feels non- gritty. It is generally very dark when moist or wet, and stains the hands brown or black.
Graininess test: Rub the soil between your fingers. If sand is present, it will feel "grainy". Determine whether sand comprises more or less than 50% of the sample. Sandy soils often sound gritty when worked in the hand.
Moist cast test: Compress some moist (not wet) soil by clenching it in your hand. If the soil holds together (i.e., forms a "cast"), then test the durability of the cast by tossing it from hand to hand. The more durable it is (eg., like plasticine), the more clay is present.
Stickiness test: Wet the soil thoroughly and compress between thumb and forefinger. Determine the degree of stickiness by noting how strongly the soil adheres to the thumb and forefinger when you release the pressure, and by how much it stretches. Stickiness increases with clay content.
Taste test: Work a small amount of soil between your front teeth. Silt particles are distinguished as fine "grittiness" (eg., like driving on a dusty road), unlike sand, which is distinguished as individual grains (i.e., graininess). Clay has absolutely no grittiness.
Soapiness test: Slide thumb and forefinger over wet soil. Degree of soapiness is determined by how soapy/slippery it feels and how much resistance to slip there is (i.e., from clay and sand particles).
Worm test: Roll some moist soil on your palm with your finger to form the longest, thinnest "worm" possible. The more clay there is in the soil, the longer, thinner, and more durable the worm will be. Try with wetter or drier soil to ensure that you have the correct moisture content (best worm).
2.
3.
4.
5.
6.
7 .
16
TABLE 5. Identification of upland humus forms
Mors - matted F horizon a
- common fungal mycelium - little or no intermixing of organic and mineral materials - abrupt boundary between organic and mineral horizons
- loosely arranged F horizon - friableb
- insect droppings - fungal mycelium and soil organisms (arthropods and occasional
- intermixing of organic and mineral horizons - gradual transition between mineral and organic horizons
- often no F or H horizons c (thin if present) - insect droppings abundant - usually many soil organisms, but may form from decomposition of a
- considerable intermixing of mineral and organic layers, with
Moders
earthworms)
Mulls
dense network of roots (usually abundant earthworms)
incorporation of organic matter into surface mineral soil (Ah horizond)
a
b
c
d
F horizon: horizon in which partial (rather than entire) macroscopically recognizable vegetative structures are dominant (ie., the horizon is partially decomposed). Residues break down upon rubbing. H horizon: horizon of highly decomposed organic matter in which original plant vegetative structures are no longer identifiable. Ah horizon: surface mineral horizon enriched with organic matter (characteristically darker in colour than lower soil layers).
17
Step 3
Using the site and soil factors recorded, determine the relative moisture regime and relative nutrient regime using the keys provided (Figure 6 and 7), and then proceed to Step 4.
TABLE 6. Definitions of terms used in the identification of relative soil moisture regimesa
Category Definition
Ridge crest: - height of land usually convex slope shape.
Upper slope:
Middle slope:
Lower slope:
- the generally convex-shaped, upper portion of a slope.
- the portion of a slope between the upper and lower slopes; the slope
shape is usually straight.
- the area towards the base of a slope; the slope shape is usually
concave. It includes toe slopes, which are generally level areas located directly below and adjacent to the lower slope.
- any level area (excluding the slopes); the surface shape is generally
horizontal with no significant aspect.
post-glacial, active floodplain deposits along rivers and streams in valley bottoms; usually a series of low benches and channels.
any area that is concave in all directions; usually at the foot of a slope or in flat topography.
- depth from the mineral soil surface to a restricting layer, such as
bedrock, strongly compacted materials, or strongly cemented materials (eg., "hardpan").
- soils that have orange-coloured mottles indicative of a fluctuating
water table. Permanently gleyed soils are dull yellowish, blue, or olive in colour.
sand b with > 35% volume of coarse fragments, or loamy
b with > 70% volume of coarse fragments.
siltyb or clayeyb with < 20% volume of coarse fragments.
Flat:
Alluvium: -
Depression:
Soil depth:
-
Gleyed:
Soil particle: size coarse:
Soil particle size fine:
-
-
a
b Adapted from Lloyd et al. (1990) and Green et al. (1984). Sandy - LS, S; loamy - SL, L, SCL; clayey - SiCL, CL, SC, Sic, C; silty - SiL, Si.
Relative soil moisture regimes: Figure 6 is intended to assist the user in identifying relative soil moisture regimes using readily observable environmental features. It should be applied with caution on ridge crests, upper slopes, and middle slopes that have soils with thick (> 20 cm) organic layers, and on steep, northerly facing slopes. Moisture regime in these cases will generally be higher than indicated. The soil moisture regime classes 0 - 7, shown in the key, correspond to the terms very xeric (0) to subhydric (7) (see Figure 3). Table 6 provides definitions for the categories used in the key shown in Figure 6.
18
1 Generally moister if aspect is N or NE 2 Generally drier if aspect is S or SW
FIGURE 6. A key to the identification of relative soil moisture regimes.
19
la Coarse textured 4
2a High coarse fragments (> 50%), very shallow soil (< 30 cm), and/or shallow rooting depth (< 15 cm)
3a Mor humus form Very Poor
3b Moder humus form Poor - Medium
Moderate to low coarse fragments without restricted rooting depth
4a Mor humus form
4b Moder humus form Medium
4c Mull humus form Rich - Very Rich
2b
l b Moderately coarse and medium textured
5a High coarse fragments (> 50%), very shallow soil (< 30 cm), and/or shallow rooting depth (< 15 cm)
6a Mor humus form Poor
6b Moder humus form Medium
Moderate to low coarse fragments without restricted rooting depth
7a Mor humus form Poor - Medium
7b Moder humus form Medium - Rich
7c Mull humus form
5b
1c Moderately fine and fine textured
8a High coarse fragments (rare), very shallow soil (< 30 cm), and/or shallow rooting depth (< 15 cm)
9a Mor humus form Poor - Very Poor
9b Moder humus form Poor - Medium
9c Mull humus form
Moderate to low coarse fragments without restricted rooting depth
10a Mor humus form Medium
10b Moder or Mull humus form
Key for estimating relative soil nutrient regimes. Note: presence of base-rich parent materials (limestone, shales, basalt) may improve nutrient status.
8b
FIGURE 7.
4
Refer to soil textural triangle (p.15) for derivation of soil textures.
20
Poor
Very Rich
Rich
Rich
Step 4
From a plot area of at least 0.04 ha (20 x 20 m), identify and record as many of the plant species (including tree species) in the plot as possible. Estimate the percent cover of each of the dominant species (ie., species covering > 5% of the plot). Attempt to adjust the list and coverage estimates according to what you have seen over the remainder of the area covered by the same unit.
Step 5
If the biogeoclimatic unit has previously been determined, proceed to the appropriate biogeoclimatic unit subsection (Table 7). If not, use Figure 8 to determine it. Note that the vegetation used in Figure 8 is that occurring on zonal sites (eg., edatopic grid 4-C (see Section 2.2). If the site unit is other than zonal, try to locate a zonal site in the area and note the general floristic features (eg., dominant tree and understory species), and compare this information to that found in Figure 8. If the area in question is near a subzone boundary and doubt remains after the verification step using Figure 8, then identify the site unit for both possible biogeoclimatic units. The descriptions and interpretations for both units should then be compared, and the most appropriate information applied.
TABLE 7. Sections and page numbers of biogeoclimatic unit subsections
Biogeoclimatic Unit Section Page Number
SBBdk 4.1 31
SBSdw2 4.2 63
SBSdw3 4.3 92
SBSmc2 4.4 119
SBSmc3 4.5 150
SBSmk1 4.6 174
SBPSmc 4.7 202
ESSFmv1 4.8 222
21
Biogeoclimatic Units SPBS SBS SBS SBS SBS SBS SBS SBS SBS SBS ESSF SBS
mc dw2 dw3 dk mh mw mk1 mk2 mc2 mc3 mv1 wk
Trees
Picea glauca x engelmannii
Shrubs
Pseudotsuga menziesii
Abies lasiocarpa
Corylus cornuta
Amelanchier alnifolia
Rosa acicularis
Vaccinium membranaceum
Rhododendron albiflorum
Herbs and Dwarf Shrubs
Arctostaphylos uva-ursi
Disporum hookeri
Calamagrostis rubescens
Aster conspicuus
Lathyrus nevadensis
Aralia nudicaulis
Clintonia uniflora Arnica cordifolia
Rubus pubescens
Gymnocarpium dryopteris Rubus pedatus
Mosses and Lichens
Mnium spp
FIGURE 8. Zonal vegetation of biogeoclimatic units within and adjacent to area covered by the guide.
Douglas-fir
hybrid white spruce
subalpine fir
beaked hazelnut
saskatoon prickly rose
black huckleberry
white-flowered rhododendron
kinnikinnick
hooker's fairy bells
pinegrass showy aster
purple peavine
false sarsaparilla
queen's cup
heart -leaved arnica
trailing raspberry
five-leaved bramble
oak fern
reindeer lichens
step moss
leafy mosses
Prominence class:
Cladina sppHylocomium splendens
3.5 Identifying Seral Ecosystems
The biogeoclimatic classification was developed based on samples of climax and late seral vegetation (forest stands older than 80 years). Because of this, environmental features must be more heavily relied upon when attempting to assess recently disturbed or seral sites. Since there can be considerable overlap in environmental features among site series, disturbed sites are often difficult to identify. Remnant climax vegetation found in portions of the site not subjected to burning or heavy mechanical site preparation may help in the assessment. Otherwise, vegetation found in an adjacent mature stand with similar environmental features (eg., same slope position and soil texture) can be used.
3.6 Mapping Site Units
An ecosystem map is an extremely useful tool for effective integrated planning within a management area. It provides a permanent record of the location and distribution of ecosystems, and thus a basic framework for developing site- specific management prescriptions that can be prepared for many resource values. A map also provides a means of monitoring prescriptions in the long term, and of refining interpretations. Pre-Harvest Silviculture Prescriptions (PHSPs) legally require biogeoclimatic classification of proposed cutblocks. Having done this, the extra effort required to produce a map of a small management area during an ecological stand survey is minimal. If the survey is initiated with mapping in mind, a more systematic, efficient, and thorough survey will result.
The steps involved in producing an ecosystem (or treatment unit) map at a scale of 1:5000 to 1:20 000 for a relatively small management unit (less than 500 ha) are outlined below. More complex ecosystem maps of large study areas (watersheds or local resource use planning areas) are generally produced by mapping specialists. Several consultants with experience in these larger projects are available throughout the province. Mitchell et al. (1989) outline standard methods and terminology for ecosystem mapping used by the Ministry of Forests, and Courtin et al. (1989) describe an approach to woodlot management that incorporates ecological stand mapping. The user should refer to these publications for more detail on mapping concepts and procedures. The major steps required to produce an ecological stand map are: (1) production of a preliminary legend, (2) pre-stratification (typing) of aerial photographs, (3) systematic field survey, (4) refinement of photo typing and labelling of map polygons, and (5) production of the final map.
3.6.1 Producing a preliminary legend
In its simplest form, a legend is a listing and explanation of abbreviations (numbers, letters, symbols) used to denote the site units that occur within the map area. For the most part, the listing of site units described for each of the biogeoclimatic units will serve as a preliminary legend. Other stand or site attributes can also be added, depending on the requirements of the survey. For example, symbols for stand age, tree species composition, or percentage of slope might supplement the site unit numbers or letters. Such a legend will enable you to place a preliminary label on polygons (map delineations) outlined on the aerial photos.
23
3.6.2 Typing aerial photographs
Assuming that aerial photographs of an appropriate scale are available (preferably 1:10 000 colour, but 1:20 000 or 1:15 840 black-and-white are also used), the next step is to delineate (using a stereoscope and grease pencil) logical, homogeneous units on the photos that reflect ecological site characteristics. Many features visible on aerial photos provide clues to identifying ecological site units. Important features to note are landform, slope position and degree, slope shape (concave versus convex), aspect, drainage pattern, and canopy characteristics (based on tone and texture) that will reflect crown closure, species composition, and relative growth or productivity. Skills improve with practice and with ground truthing of photo typing to calibrate the eyes. Use the various tools in the guide, and your experience, to predict which site units occur in each of your types (polygons). Then, put a tentative label (using site series numbers or other abbreviations from your legend) on each. Complex polygons comprised of two or three units can only be identified on the ground. Polygons should not generally be smaller than 1 cm2, which represents .25 ha and 1 ha at 1:5000 and 1:10 000 scales, respectively. Exceptions to this would be small, easily recognizable features such as wetlands and clearings, which aid in orientation and/or may require special consideration.
3.6.3 Field surveys (ground truthing)
Accurately typed photos facilitate efficient field sampling. Once the typing is complete, compile a sampling plan, ensuring that at least two plots are present in each type. Complex types may require more plots. After establishing plots, sample and describe each of the types as outlined in Section 3.3.1, and identify site units as outlined in Section 3.3.2. Transects through the area should be walked with a compass and hip chain, in order to cover all the polygons that were pre-stratified. Take care to locate your plots and transects accurately on the photo. In addition to recording the plot information, take notes as you walk, and record changes that occur at specified distances along the transects.
3.6.4
The next step is to refine the map polygon boundaries and labels on the aerial photos, based on the results of the field survey. As the transects and sample plots are completed in the field, type lines and labels are modified while the information is fresh in your mind. The legend may have to be modified to accommodate previously undescribed units. Once back in the office, finalize the linework, polygon labels, and legend. It may be desirable to combine similar polygons into "treatment units" if you feel that the units are not significantly different ecologically to warrant different operational treatments. It is preferable, however, to maintain as much detail as possible on the original map. From this, more generalized interpretive maps can be produced for specific applications.
3.6.5 Producing the final map
The exact form of the final map will depend on its proposed use and the resources available to produce it. The final product may range from a simple sketch map to a sophisticated colour-themed digital (computer- generated) map. For small settings, where the topography does not vary
Refining and labelling map polygons
24
much and the map is not very complex, it may be adequate to trace the photo linework and some of the important planimetric detail (streams, lakes, roads) onto a mylar in order to produce the final map. For larger maps encompassing more than two aerial photos, or where the topography is variable and steep, the linework will have to be transferred to a base map using special plotting equipment (eg., a Kail plotter, zoom transfer scope, or epidiascope) that corrects for distortion of scale on the photos. There are several mapping firms throughout the province that specialize in Geographic Information Systems (GIS) and the production of digital map products, either directly from aerial photos or from a plotted map. Digital maps are extremely useful for permanent storage of a large amount of field data by map polygon. They are ideal for producing interpretive maps and monitoring long-term treatments tied to specific map units.
3.7 Management Interpretations
Interpretations are provided in two areas of the guide. Within the biogeoclimatic unit subsections (4.1 - 4.8) are direct interpretations. These relate to specific site units and are contained on the page facing the appropriate unit. Section 5 contains interpretations that can be made at a more general level than the site series, or those that are best handled by indirect interpretation methods that incorporate factors other than moisture and nutrient regime.
3.7.1 Direct interpretations
On the page facing each site unit description is a variety of direct interpretations that have been grouped under the subheadings described below.
Site limitations: This section contains statements about ecological conditions that may place limitations on forest productivity or forest operations. The limitations may be either generally applicable to the site unit, or specific to sites with a particular, identified ecological condition. For example, the phrase "sites within this unit with high coarse fragment content (> 70%) will have significantly reduced soil moisture retention and will be extremely difficult to plant" refers only to sites within the site unit whose soils contain greater than 70% coarse fragments. After each site limitation listed there are recommended solutions to deal with the limitation. This information is in bold italic text.
Silviculture system: This section contains, or directs the user to a section that contains, information on silviculture system options. Harvesting recommendations or cautions are also contained here.
Site preparation: This section contains site preparation options or directs the user to site preparation keys in Section 5.2. Occasionally, specific comments relating to site preparation are also found here.
Species choice: This section contains species selection information that has been correlated at the site series level across the province. General use species are shown in normal type. Species that have one or more restrictions are in bold italic. The restrictions relating to species in bold
25
italic are found in one of three sections: site limitations, reforestation, or concerns. When users encounter a species in bold italic, restrictions applicable to that species should be determined by examining these sections. Species found in square brackets (eg., [Pl]) are species of secondary choice due to a lower ranking of reliability, productivity, or silvicultural feasibility. Species indicated with round brackets (eg., (Sx, Sb)) are generally significantly less productive than other ecologically acceptable species on the site unit. These species are restricted to comprising a minor proportion (eg., 20-30%) of the stand or area. These species could be used in only a few localities or blocks within an area, as a minor component of all plantations, or only in test trials. The most recent version of the correlated tree species selection guidelines was used to compile the species choice lists. Minor discrepancies may surface, however, so the user of the guide should attempt to get the most up-to- date guidelines before making final choices.
Vegetation potential: This section subjectively rates the potential of the site to produce non-crop vegetation that may pose a risk to the survival and target growth of the crop tree. Vegetation species posing the greatest potential threat to the crop tree are listed in brackets when the potential is rated moderate or greater. Before treatments are prescribed to manage these species, the Wildlife Interpretations Section (Section 5.3). should be used to determine the importance of the species present to wildlife.
Reforestation: This section contains specific instructions related to reforestation on the site unit (eg., plant Fd only on south-facing, coarse- textured sites within its natural range).
Concerns: This section contains concerns of which the user should be aware when preparing a prescription or carrying out forestry operations on a site. Potential solutions to alleviate these concerns are indicated in bold italic text where appropriate.
3.7.2 Indirect and general interpretations
Indirect and general interpretations are contained within the following sections; Silviculture Systems (Section 5.1), Site Preparation (Section 5.2), and Wildlife (Section 5.3). Users should familiarize themselves with this information when using the guide.
26
4 BIOGEOCLIMATIC AND SITE UNIT DESCRIPTIONS AND INTERPRETATIONS
The area this guide covers is primarily in the Sub-Boreal Spruce (SBS) zone. The exception is the Sub-Boreal Pine - Spruce (SBPS) zone located in the southwest corner of the study area, and higher-elevation areas in the southwest corner of the study area that are in the Engelmann Spruce - Subalpine Fir (ESSF) zone (Figure 1). The area is predominantly a plateau landscape between the Coast Mountains to the west and the Rocky Mountains to the east. The climate can be broadly described as continental, and is characterized by seasonal extremes of temperature, severe snowy winters, relatively warm, moist, and short summers, and moderate precipitation (Table 8). The portions of the guide area situated in the ESSF (ESSFmv1) are the wettest and coldest, while the SBSdk is the driest and the SBSdw2 is the warmest. Table 8 compares climatic data for biogeoclimatic units described in the guide except for the ESSFmv1, which has no available data.
The study area contains climax forests dominated by hybrid white spruce (Picea engelmannii x glauca) or Engelmann spruce (Picea engelmannii) and/or subalpine fir (Abies lasiocarpa). Lodgepole pine (Pinus contorta), a fire climax species in portions of the area, is common in mature forests. Trembling aspen (Populus tremuloides) and lodgepole pine pioneer extensive seral stands. Black spruce (Picea mariana) is common in wetland areas and upland sites on poorer soils. Other tree species’ ranges are restricted within the guide area and are discussed in the introductory comments for each biogeoclimatic unit. Figure 8 compares characteristic vegetation of the different biogeoclimatic units described and can be a useful tool in determining biogeoclimatic units in the field, especially near unit boundaries. Table 9 provides lists of important wildlife species that use the biogeoclimatic units described. The biogeoclimatic units covered in this guide are SBSdk, SBSdw2, SBSdw3, SBSmk1, SBSmc2, SBSmc3, SBPSmc, and ESSFmv1.
27
TABLE 8. Summary of climate data for biogeoclimatic units a
Biogeoclimatic Unit
Climatic SBSdk SBSdw2 SBSdw3 SBSmk1 SBSmc2 SBSmc3 SBPSmc Characteristics
Annual Precipitation Mean 480.6 552.9 494.4 727.4 574.4 505.6 N/A
(mm) Range 415.9 - 586.3 427.0 - 648.5 N/A 628.3 - 838.2 460.1 N/A N/A
Growing Season Mean 211.0 274.8 259.4 272.6 229.4 261.4 195.9
Precipitation (mm) Range 167.4 - 323.0 248.0 - 296.3 224.1 - 298.4 196.8 - 432.0 139.4 - 348.9 242.8 - 288.7 156.0 - 235.5
Annual Snowfall Mean 188.1 204.1 204.2 306.3 237.1 197.1 N/A
(cm) Range 121.9 - 265.2 169.8 - 225.8 N/A 241.7 355.5 177.3 - 264.0 N/A N/A
Annual Temperature Mean 2.1 3.4 2.6 1.5 1.5 0.6 0.8
(°C) Range 0.8 - 3.5 2.0 - 4.4 1.3 - 3.5 -0.2 - 3.3 -0.7 - 3.6 N/A 0.7 - 0.8
Growing Degree-days Mean 1028 1224 1089 975 947 N/A N/A
(>5°C) Range 884- 1145 1072- 1409 N/A 751 - 1198 844 - 1012 N/A N/A
Frost-free Period Mean 70 105 83 73 116 18 N/A
(days) Range 3 9 - 103 94 - 122 N/A 43 - 92 106- 125 N/A N/A
a
Reynolds, G. 1989. Climatic data summaries for the biogeoclimatic zones of British Columbia. B.C. Min. For., Research Branch, Victoria, B.C. Unpublished report.
TABLE 9. Some important wildlife species that use biogeoclimatic units in the West Central guide area
Occurrence in Variants
Species SBSdk SBSdw2 SBSdw3 SBSmc2 SBSmc3 SBSmk1 SBPSmc ESSFmv1
Moose * * * * * * (winter range)
Mule Deer * * * * * * (winter range)
White-tailed Deer * * * *
Elk *
Caribou a * * * *
Grizzly Bear a * * * * * * * *
Furbearers * * * * * * * *
a
Denotes species " blue listed" in 1989 by the Ministry of Environment. Because of major declines in their populations, they are considered sensitive and/or deserving of management attention.
4.1 Dry Cool Sub-Boreal Spruce 5
Location The SBSdk occurs at lower elevations in the western portion of the Prince George Forest Region. It occurs in two main areas: west of Vanderhoof, and north and west of Fort St. James. The SBSdk reaches its eastern extent in the Prince George Forest Region and is more widespread in the Prince Rupert Region.
Elevation range 700 - 1050 m
Climate The SBSdk is the driest of the variants described, but is intermediate in temperature (Table 8).
Soils, geology, and landforms Bedrock types consist mostly of upper Palaeozoic sedimentary rocks and Jurassic intrusives (diorite). Parent materials are dominantly lacustrine and morainal. The lacustrine materials are usually fine textured (silty clay, silty clay loam) and are associated with Gray Luvisolic soils, although Dystric Brunisols occur on coarser lacustrine deposits with fine sandy loam textures. Gray Luvisols have formed on morainal materials with gravelly loam and clay loam textures. Dystric Brunisols and Humo-Ferric Podzols occur on more limited areas of coarse-textured (loamy sand and gravelly sandy loam) glaciofluvial and colluvial materials.
Distinguishing the SBSdk from adjoining biogeoclimatic units SBSdw3 has: • Douglas-fir on mesic sites; and • no purple peavine in the herb layer.
SBSmc2 has: • subalpine fir present in the canopy; • black huckleberry but less prickly rose in the shrub layer; and • five-leaved bramble but no purple peavine in the herb layer.
SBSmc3 has: • subalpine fir present in the canopy; and • no purple peavine in the herb layer.
Forests Due to the recurrent disturbances in this variant, forested areas are often dominated by lodgepole pine and trembling aspen. Climax forests are dominated by hybrid white spruce with subalpine fir generally absent. Douglas- fir (Pseudotsuga menziesii) occurs as a long-lived seral species on drier sites, and is often associated with bedrock outcrops. Black spruce is restricted to wetlands. Paper birch (Betula papyrifera) occurs sporadically, often in
5 Formerly SBSd.
31
combination with Douglas-fir. Black cottonwood (Populus balsamifera ssp. trichocarpa) occurs along streams and rivers and is often associated with hybrid white spruce.
Wildlife Douglas-fir stands provide important winter habitat for mule deer, and are used by black bear, gray wolf and coyote. Shrub-dominated, steep, southerly aspects are used by mule deer, coyote, sharp-tailed grouse and, in the early spring, by black bear. South-facing slopes dominated by trembling aspen provide habitat for mule deer, moose, grizzly bear, black bear, coyote and ruffed grouse. Habitat in and around small lakes is used by moose, gray wolf, beaver, muskrat, mink and otter, and birds such as osprey, bald eagle and cavity nesters. Shrub-dominated wetlands below 900 m elevation provide important winter habitat for moose. Shrub-dominated wetlands also support beaver, muskrat, mink, otter and, in some areas, sandhill cranes. The extensive sub- boreal coniferous forests provide habitat for moose, mule deer, grizzly bear, black bear, white-tailed deer, spruce grouse, and furbearers, including wolverine, marten, and red squirrel.
32
Soil Nutrient Regime
Very Poor Poor Medium Rich Very Rich
A B C D E
Very Xeric 0
Xeric 1
Subxeric 2
Submesic 3
Mesic 4
Subhygric 5
Hygric 6
Subhydric 7
01 Sxw - Spirea - Purple peavine
02 Pl - Juniper - Ricegrass 81 Saskatoon - Slender 07 Sxw - Horsetail
wheatgrass (scrub/steppe) 03 Pl - Feathermoss - Cladina
04 Fd - Soopolallie - Feathermoss
82 Bluegrass - Slender
05 Sxw - Spirea - Feathermoss
06 Sxw - Twinberry - Coltsfoot
08 Act - Dogwood - Prickly rose
09 Sb - Creeping snowberry -
Sphagnum (forested bogs) 10 Sb - Soft-leaved sedge -
wheatgrass (grasslands) Sphagnum (forested swamps)
FIGURE 9. Edatopic grid displaying site units in the SBSdk subzone.
33
Site Units 81 82 02 03 04 05 01 06 07 08 09 10
Trees
Juniperus scopulorum
Pseudotsuga menziesii
Pinus contorta
Populus balsamifera
ssp. trichocarpa
Picea mariana
Amelanchier alnifolia
Juniperus communis
Shepherdia canadensis
Spiraea betulifolia
Rosa acicularis
Viburnum edule
Rubus parviflorus
Lonicera involucrata
Cornus stolonifera
Betula glandulosa
Ledum groenlandicum
Herbs and Dwarf Shrubs
Poa spp.
Agropyron trachycaulum
Koeleria macrantha
Aster conspicuus
Shrubs
Arctostaphylos uva-ursi
FIGURE 10. SBSdk vegetation table
Rocky Mountain juniper
Douglas-fir
lodgepole pine
black cottonwood
black spruce
saskatoon
common juniper
soopolallie
birch-leaved spirea
prickly rose
highbush-cranberry
thimbleberry
black twinberry
red-osier dogwood
scrub birch
labrador tea
bluegrasses
slender wheatgrass
junegrass
kinnikinnick
showy aster
Prominence class: 1
Site Units 81 82 02 03 04 05 01 06 07 08 09 10
Herbs and Dwarf Shrubs
(continued)
Lathyrus nevadensis
Calamagrostis canadensis
Equisetum arvense
Carex disperma
Equisetum fluviati le
Gaultheria hispidula
Pleurozium schreberi
Mnium spp.
Tomenthypnum nitens
Sphagnum capilllaceum
Mosses
FIGURE 10. SBSdk vegetation table (continued).
purple peavine
bluejoint common horsetail
soft-leaved sedge
swamp horsetail
creeping-snowberry
red-stemmed feathermoss
leafy mosses
golden fuzzy fen moss
common red sphagnum
Prominence class:
l a Tree canopy absent or dominated by black spruce; unproductive forest on organic soils or grasslands.
2a Tree canopy absent; generally on warm (southerly facing) slopes; grassland vegetation.
3a Usually on shallow soils over bedrock; shrub layer generally well developed; herb layer dominated by Agropyron trachycaulum (p. 231). 6
SBSdk/81
Usually on deep soils; shrub layer absent or poorly developed; herb layer dominated by Poa spp. (pp. 249-252).
3b
SBSdk/82
Tree canopy dominated by black spruce; found in depressions; wetland vegetation.
4a
2b
White spruce often in the canopy; shrub layer dominated by Betula glandulosa (p. 39); herb layer well developed.
SBSdk/10
White spruce absent from canopy; shrub layer dominated by Ledum groenlandicum (p. 40); herb layer poorly developed.
4b
SBSdk/09
Canopy present and dominated by species other than black spruce; productive forest on mineral soils.
5a
1b
Canopy dominated by lodgepole pine or Douglas-fir; on coarse soils or shallow soils over rock; shrub layer dominated by Shepherdia canadensis (p. 49) or very poorly developed.
6a Canopy dominated by Douglas-fir; herb layer poorly developed and Arctostaphylos uva-ursi (p. 82) generally absent.
SBSdk/04
Canopy dominated by lodgepole pine; herb layer poorly to well developed and Arctostaphylos uva-ursi generally present.
6b
6 Page numbers refer to the publication Plants of Northern British Columbia (MacKinnon et al. 1992)
36
7a On shallow soils over bedrock; moss layer dominated by lichens.
SBSdk/02
On coarse-textured glaciofluvial soils as well as shallow soils over bedrock; moss layer dominated by mosses.
7b
SBSdk/03
5b Canopy dominated by lodgepole pine, white spruce, or black cottonwood; soils variable; shrub layer generally well developed and dominated by species other than Shepherdia canadensis.
8a Canopy dominated by black cottonwood; found on lower fluvial terraces adjacent to watercourses.
SBSdk/08
Canopy dominated by lodgepole pine or white spruce; found in various locations in the landscape.
9a
8b
Located on fluvial terraces adjacent to watercourses or as narrow bands along draws; Equisetum spp. (p. 281) abundant (> 5% cover).
SBSdk/07
Upland sites; Equisetum spp. low cover (< 5% cover) or absent.
10a Shrub layer poorly developed; Lathyrus nevadensis
9b
(p. 168) low cover (< 1%) or absent. SBSdk/05
10b Shrub layer generally moderately to well developed; Lathyrus nevadensis moderate to high cover (> 1%).
11a Evidence of seepage (eg., mottles) generally present in soil profile; shrub layer well developed.
SBSdk/06
11b Evidence of seepage generally lacking; shrub layer moderately to poorly developed.
SBSdk/01
37
Rosa acicularis
Lathyrus nevadensis
Sxw - Spirea - Purple peavine
VEGETATION
Tree Layer: 55% cover hybrid white spruce, lodgepole pine, [trembling aspen]
Shrub Layer: 30% cover Rosa acicularis (prickly rose) [Shepherdia canadensis (soopolallie)] hybrid white spruce
Herb Layer: 55% cover Lathyrus nevadensis (purple peavine) Aster conspicuus (showy aster) Cornus canadensis (bunchberry) Linnaea borealis (twinflower) Epilobium angustifolium (fireweed) Arnica cordifolia (heart-leaved arnica)
Moss Layer: 70% cover Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) Hylocomium splendens (step moss) [Peltigera spp. (peltigera lichens)]
SOIL AND SITE
Moisture Regime: 3-5 (sm-shg) Nutrient Regime: B-D (p-r)
Slope Position: lower - upper Parent Material: morainal or glaciofluvial Soil Texture: variable Coarse Fragments (%): not available
Slope Gradient (%): 0-30
DISTRIBUTION: common, and widespread throughout the landscape
Aster conspicuus
38
Sxw - Spirea - Purple peavine (SBSdk/01)
INTERPRETATIONS
Site limitations: - sites within this unit with medium- to fine-textured lacustrine soils often have poor soil structure, leading to poor root growth; plant stock that will achieve better lateral root development (eg., Cu-treated), prescribe natural regeneration, or protect advance regeneration.
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
Site preparation: - see Section 5.2
Species choice: - Pl, Sx, [Fd]
Vegetation potential: - low to moderate (trembling aspen, fireweed, prickly rose)
Reforestation: - attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant a mix of
Pl and Sx or Pl and Fd. - plant Fd only on south-facing slopes within its
natural range. - to help maintain stand diversity on sites to be
planted with Pl, map aspen patches prior to harvest and plant these areas to spruce.
Concerns: - full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (ie., lop and scatter).
- site conditions may lead to frost damage of Fd and Sx regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) is advised.
- windthrow risk after partial cutting will be high on sites where a root-restricting layer occurs at depths of < 25 cm.
- comandra blister rust may cause cankers on pine if bastard toad-flax (Geocaulon lividum) occurs nearby.
39
Juniperus communis
Arctostaphylos uva-ursi
1 cm
Pl- Juniper - Ricegrass
VEGETATION
Tree Layer: 35% cover lodgepole pine
Shrub Layer: 30% cover Juniperus communis (common juniper) [Shepherdia canadensis (soopolallie)] lodgepole pine
Herb Layer: 20% cover Arctostaphylos uva-ursi (kinnikinnick) Oryzopsis spp. (ricegrasses)
Moss Layer: 45% cover Cladina spp. (cladina lichens) Cladonia spp. (cladonia lichens)
Peltigera spp. (peltigera lichens)
SOIL AND SITE
Moisture Regime: 1 (x) Nutrient Regime: A-B (vp-p) Slope Gradient (%): 20-30
* Slope Position: * Parent Material:
upper or crest colluvial or morainal veneers over bedrock
Soil Texture: moderately coarse - coarse Coarse Fragments (%): not available
DISTRIBUTION: uncommon, and usually located on or around exposed bedrock
Cladina spp.
40
Pl - Juniper - Ricegrass (SBSdk/02)
INTERPRETATIONS
Site limitations: - site and soil conditions of this unit result in marginal forest productivity; serious consideration should be given to excluding logging from this unit.
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard
Site preparation: - light scarification for seedbed preparation or summer logging with no site preparation
Species choice: - Pl, (Sx)
Vegetation potential: - low
Reforestation: - attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant Pl. - Sx is significantly less productive on these sites than
Pl.
Concerns: - full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (ie., lop and scatter)
- site and soil conditions of this unit result in drought hazard for a significant portion of the growing season; natural regeneration is generally more adapted to surviving these conditions, especially during establishment.
- sites within this unit with shallow and/or coarse- textured soils are vulnerable to nutrient deficiency if forest floors are reduced; site preparation methods that reduce forest floor thickness, such as slashburning or brushblading, must be avoided.
- comandra blister rust may cause cankers on pine if bastard toad-flax (Geocaulon lividum) occurs nearby.
41
Amelanchier alnifolia
Agropyron trachycaulum
Saskatoon - Slender wheatgrass
VEGETATION
Tree Layer: 0% cover
Shrub Layer: 45% cover Amelanchier alnifolia (saskatoon) Symphoricarpos albus (common snowberry) Prunus virginiana (choke cherry) Rosa acicularis (prickly rose) Juniperus scopulorum (Rocky Mountain juniper)
Herb Layer: 80% cover Agropyron trachycaulum (slender wheatgrass) Phleum pratense (timothy) Galium boreale (northern bedstraw) Stipa richardsonii (spreading needlegrass) Lathyrus nevadensis (purple peavine) Poa interior (inland bluegrass)
Moss Layer: 15% cover Tortula ruralis (sidewalk moss)
SOIL AND SITE
Moisture Regime: 1-2 (x-sx) Nutrient Regime: C-E (m-vr)
* Slope Gradient (%): 23-81 * Slope Position: * Aspect: south to southwest
mid and upper
Parent Material: morainal; colluvial or
Soil Texture: Coarse Fragments (%): not available
morainal over bedrock medium - moderately coarse
DISTRIBUTION: restricted to steep south-facing slopes in the southern portion of the subzone
Phleum pratense
42
Saskatoon - Slender wheatgrass (SBSdk/81)
INTERPRETATIONS
Site limitations: - these sites are non-forested, subject to drought, and can provide critical seasonal wildlife range; no attempt should be made to establish a forest on these sites.
43
Shepherdia canadensis
Arctostaphylos uva-ursi
Pl - Feathermoss - Cladina
VEGETATION
Tree Layer: 40% cover lodgepole pine, [hybrid white spruce], [trembling aspen]
Shepherdia canadensis (soopolallie) Rosa acicularis (prickly rose) lodgepole pine [hybrid white spruce]
Herb Layer: 40% cover
Shrub Layer: 30% cover
Arctostaphylos uva-ursi (kinnikinnick) Linnaea borealis (twinflower) Vaccinium caespitosum (dwarf blueberry) [Oryzopsis spp. (ricegrasses)]
Pleurozium schreberi (red-stemmed feathermoss) Cladina spp. (cladina lichens) [Hylocomium splendens (step moss)] [Cladonia spp. (cladonia lichens)]
Moss Layer: 75% cover
SOIL AND SITE
Moisture Regime: 2 (sx) Nutrient Regime: A-C (vp-m)
Slope Position: level, upper, and crest Parent Material: glaciofluvial; morainal and
colluvial veneers over bedrock moderately coarse - coarse often >35
* Slope Gradient (%): 0-10
* Soil Texture: * Coarse Fragments (%):
DISTRIBUTION: common, but localized
Pleurozium schreberi
44
Pl - Feathermoss - Cladina (SBSdk/03)
INTERPRETATIONS
Site limitations: - site and soil conditions of this unit result in marginal forest productivity; serious consideration should be given to excluding logging from this unit.
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
Site preparation: - light scarification for seedbed preparation or summer logging with no site preparation.
Species choice: - Pl, (SX, Sb)
Vegetation potential: - low
Reforestation: - attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant Pl. - Sx and Sb will be less productive on these sites than
Pl.
Concerns: - full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (ie., lop and scatter).
- site and soil conditions of this unit result in drought hazard for a significant portion of the growing season; natural regeneration is generally more adapted to surviving these conditions, especially during establishment.
- sites within this unit with shallow and/or coarse- textured soils are vulnerable to nutrient deficiency if forest floors are reduced; site preparation methods that reduce forest floor thickness, such as slashburning or brushblading, must be avoided.
- comandra blister rust may cause cankers on pine if bastard toad-flax (Geocaulon lividum) occurs nearby.
45
Shepherdia canadensis
Elymus glaucus
Fd - Soopolallie - Feathermoss
VEGETATION
Tree Layer: 45% cover Douglas-fir, [hybrid white spruce], [subalpine fir]
Shrub Layer: 40% cover Shepherdia canadensis (soopolallie) Spiraea betulifolia (birch-leaved spirea) Rosa acicularis (prickly rose) Douglas-fir [hybrid white spruce]
Herb Layer: 15% cover [Elymus glaucus (blue wildrye)] [Linnaea borealis (twinflower)] [Festuca occidentalis (western fescue)]
Moss Layer: 45% cover Pleurozium schreberi (red-stemmed feathermoss) Hylocomium splendens (step moss) [Cladonia spp. (cladonia lichens)]
SOIL AND SITE
Moisture Regime: 2-3 (sx-sm) Nutrient Regime: C-D (m-r)
Slope Position: mid to upper Slope Gradient (%): 0-65
* Aspect: generally southerly * Parent Material: morainal or colluvial
moderately coarse - medium Soil Texture: Coarse Fragments (%): not available
DISTRIBUTION: usually on or near south-facing bedrock outcrops or ridges, in the vicinity of some of the larger lakes
Pleurozium schreberi
46
Fd - Soopolallie - Feathermoss (SBSdk/04)
INTERPRETATIONS
Site limitations: - sites within this unit with high coarse fragment content (> 70%) will have significantly reduced soil moisture retention and will be extremely difficult to plant; attempt to regenerate naturally by retaining Pl cones and/or leaving Fd seed-trees on site.
Silviculture system:
Site preparation:
- see Section 5.1
- light scarification for seedbed preparation or summer logging with no site preparation.
Species choice: - Fd, Pl, (Sx)
Vegetation potential: - low
Reforestation: - manage to maintain Fd component. - enough Fd stems should be left so that seed can be
distributed to as much of the site as possible. - if disturbance during logging does not expose some
mineral soil, then natural Pl and Fd regeneration should be promoted by light scarification or spot screefing.
- fill-planting may be required to meet stocking requirements.
- Sx is significantly less productive on these sites than Fd or Pl.
Concerns: - avoid clearcutting; stand establishment will be difficult because of high surface soil temperatures and drought.
- these units may represent important early season range for wildlife, so management prescriptions should be discussed with wildlife personnel.
- site and soil conditions of this unit result in drought hazard for a significant portion of the growing season; leaving a shelterwood overstory can reduce the severity of the drought hazard.
- sites within this unit with shallow and/or coarse- textured soils are vulnerable to nutrient deficiency if forest floors are reduced; site preparation methods that reduce forest floor thickness, such as slashburning or brushblading, must be avoided.
47
Poa spp.
Agropyron trachycaulum
Bluegrass - Slender wheatgrass
VEGETATION
Tree Layer: 0% cover
Shrub Layer: 5% cover [Symphoricarpos albus (common snowberry)]
Thalictrum occidentale (western meadowrue) Poa pratensis (Kentucky bluegrass) Poa gracillima (Pacific bluegrass) Poa interior (interior bluegrass) Agropyron trachycaulum (slender wheatgrass) Elymus glaucus (blue wildrye) Stipa richardsonii (spreading needlegrass) Taraxacum officinale (dandelion) Lathyrus nevadensis (purple peavine) Schizachne purpurascens (false melic) Epilobium angustifolium (fireweed)
Herb Layer: 100% cover
Moss Layer: 5% cover
SOIL AND SlTE
Moisture Regime: 2-3 (sx-sm) Nutrient Regime: D-E (r-vr)
Slope Position: variable * Aspect: south to west
Parent Material: morainal or lacustrine Soil Texture: fine - medium Coarse Fragments (%): not available
Slope Gradient (%): 0-40
DISTRIBUTION: generally restricted to south-facing slopes in southern portions of the subzone
Elymus glaucus
48
Bluegrass - Slender wheatgrass (SBSdk/82)
INTERPRETATIONS
Site limitations: - these sites are non-forested, subject to drought, and can provide critical seasonal wildlife range; no attempt should be made to establish a forest on these sites.
49
Spirea betulifolia
Geocaulon lividum
Sxw - Spirea - Feathermoss
VEGETATION
Tree Layer: 55% cover
Shrub Layer: 25% cover
hybrid white spruce, lodgepole pine
Rosa acicularis (prickly rose) Spiraea betulifolia (birch-leaved spirea) Shepherdia canadensis (soopolallie) [Alnus crispa ssp. sinuata hybrid white spruce
Herb Layer: 35% cover Cornus canadensis (bunchberry) Linnaea borealis (twinflower) Arnica cordifolia (heart-leaved arnica) [Vaccinium caespitosum (dwarf blueberry)] [Geocaulon lividum (bastard toad-flax)]
Pleurozium schreberi (red-stemmed feathermoss) Hylocomium splendens (step moss) Ptilium crista-castrensis (knight’s plume) Peltigem spp. (peltigera lichens) [Dicranum spp. (dicranum mosses)]
(Sitka alder)]
Moss layer: 90% cover
SOIL AND SITE
Moisture Regime: 3-4 (sm-m) Nutrient Regime: A-C (vp-m) Slope Gradient (%): 0-40 Slope Position: Parent Material: morainal or glaciofluvial Soil Texture: medium - coarse
Coarse Fragments (%): not available
generally mid to crest
DISTRIBUTION: common, but localized
Pleurozium schreberi
50
Sxw - Spirea - Feathermoss (SBSdk/05)
INTERPRETATIONS
Site limitations: - sites within this unit with high coarse fragment content (> 70%) will have significantly reduced soil moisture retention and will be extremely difficult to plant; attempt to regenerate naturally by retaining Pl cones and/or leaving Fd seed-trees on site.
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
Site preparation: - light scarification for seedbed preparation or summer logging with no site preparation.
Species choice: - Pl, SX, Fd
Vegetation potential: - low
Reforestation: - attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant Pl. - Sx may be planted on moister microsites. - within this unit, Fd should be planted only on sites
with low frost hazard within its natural range.
Concerns: - full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (ie., lop and scatter).
- site and soil conditions of this unit result in drought hazard for a significant portion of the growing season; natural regeneration is generally more adapted
to surviving these conditions, especially during establishment.
- sites within this unit with shallow and/or coarse- textured soils are vulnerable to nutrient deficiency if forest floors are reduced; site preparation methods that reduce forest floor thickness, such as slashburning or brushblading, must be avoided.
- comandra blister rust may cause cankers on pine if bastard toad-flax (Geocaulon lividum) occurs nearby.
51
Lonicera involucrata
Lathyrus nevadensis
Petasites frigidus
var. palmatus
Sxw - Twinberry - Coltsfoot
VEGETATION
Tree Layer: 60% cover hybrid white spruce, lodgepole pine, (trembling aspen)
Shrub Layer: 60% cover Rosa acicularis (prickly rose) Viburnum edule (highbush-cranberry) Lonicera involucrata (black twinberry) [Spiraea douglasii ssp. menziesii (pink spirea)] [Rubus parviflorus (thimbleberry)] [hybrid white spruce]
Herb Layer: 65% cover Lathyrus nevadensis (purple peavine) Epilobium angustifolium (fireweed) Rubus pubescens (trailing raspberry) Cornus canadensis (bunchberry) Linnaea borealis (twinflower) [Petasites frigidus var. palmatus (palmate coltsfoot)] [Smilacina racemosa (false Solomon’s-seal)] [Calamagrostis canadensis (bluejoint)]
Moss Layer: 65% cover Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) Hylocomium splendens (step moss)
SOIL AND SITE
Moisture Regime: 4-5 (m-shg) Nutrient Regime: C-E (m-vr)
0-37, often <10 Slope Position: variable, but often mid to
lower Parent Material: mainly morainal; sometimes
fluvial, lacustrine, or colluvial moderately fine - moderately coarse
* Slope Gradient (%):
Soil Texture:
Coarse Fragments (%): not available
DISTRIBUTION: common and widespread, especially in more northern portions of the subzone
52
Sxw - Twinberry - Coltsfoot (SBSdk/06)
INTERPRETATIONS
Site limitations: - sites within this unit with medium- to fine-textured lacustrine soils often have poor soil structure, leading to poor root growth; plant stock that will achieve better lateral root development (eg., Cu-treated), prescribe natural regeneration, or protect advance regeneration.
Silviculture system:
Site preparation:
- see Section 5.1
- see Section 5.2
Species choice: - SX, Pl, Fd
Vegetation potential:
Reforestation: -plant sturdy stock as soon after harvesting as possible.
- if vigorous advance Fd or Sx regeneration is present, it should be preserved when feasible.
- fill-planting will likely be required if a partial cutting silviculture system is used.
- Fd should only be planted on coarse-textured, low frost hazard sites within its natural range.
- help maintain stand diversity on sites to be planted with Pl by mapping aspen patches prior to harvest and planting these areas to spruce.
- moderate (black twinberry, thimbleberry, fireweed)
Concerns: - site conditions may lead to frost damage of Fd and Sx regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) is advised.
- sites within this unit with silty soils are susceptible to frost-heaving; bareroot stock will likely resist frost-heaving better than plug stock.
- sites within this unit with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations or dry soil conditions.
- windthrow risk after partial cutting will be high on sites with a root-restricting layer at depths < 25 cm.
- Warren’s root collar weevil can cause mortality in young stands, especially where duff layers are thick.
- black army cutworm can cause severe defoliation on south-facing slopes that have been slashburned.
53
Lonicera involucrata
Equisetum spp.
Sxw - Horsetail
VEGETATION
Tree Layer: 60% cover hybrid white spruce, [trembling aspen]
Shrub Layer: 50% cover Lonicera involucrata (black twinberry) Viburnum edule (highbush-cranberry) Rosa acicularis (prickly rose) Ribes lacustre (black gooseberry) [Cornus stolonifera (red-osier dogwood)] hybrid white spruce
Herb Layer: 70% cover Equisetum arvense (common horsetail) Equisetum sylvaticum (wood horsetail) Calamagrostis canadensis (bluejoint) Epilobium angustifolium (fireweed) Rubus pubescens (trailing raspberry)
Moss Layer: 60% cover Mnium spp. (leafy mosses) Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) [Brachythecium spp. (brachythecium mosses)] [Aulocomnium palustre (glowmoss)]
SOIL AND SITE
Moisture Regime: 5-6 (shg-hg) Nutrient Regime: C-E (m-vr)
* Slope Gradient (%): 0-7 * Slope Position: lower, toe, and depressions * Parent Material: lacustrine veneers over
morainal or fluvial blankets fine - medium or coarse Soil Texture:
Coarse Fragments (%): not available
DISTRIBUTION: common, but generally narrow and associated with creeks and rivers
Mnium spp.
54
Click here for next page
Sxw - Horsetail (SBSdk/07)
INTERPRETATIONS
Site limitations: - very difficult sites to manage; serious consideration should be given to managing these sites as wildlife corridors.
- sites within this unit with saturated soils are poorly aerated, which slows root development; plant seedlings on naturally or artificially raised microsites.
Silviculture system:
Site preparation:
- see Section 5.1
- see Section 5.2 - creating an excessive number of mounds (eg.,
>300/ha) should be avoided, especially on sites within this unit with a water table < 30 cm from the surface.
Species choice: - Sx, [Pl]
Vegetation potential:
Reforestation:
- high (black twinberry, fireweed, bluejoint)
- advance regeneration should be preserved. - supplement advance regeneration by planting sturdy
- low ground-pressure vehicles should be used when stock in groups on available microsites.
treating these sites.
Concerns: - site conditions may lead to frost damage of Sx regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) is advised.
- sites within this unit with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations.
(>10 cm) have increased windthrow hazard; block layouts must have windfirm boundaries, or a
wide buffer of standing timber must be left around such sites.
- these units may represent important habitat for wildlife, so prescription should be discussed with wildlife personnel.
- water table will likely rise above the ground surface in the spring, causing seedling mortality.
- this association is critical to the control of runoff and streamflow.
- Warren’s root collar weevil can cause mortality in young stands, especially where duff layers are thick.
- sites within this unit with thick organic horizons
55
Cornus stolonifera
Calamagrostis
canadensis
Act - Dogwood - Prickly rose
VEGETATION
Tree Layer: 45% cover black cottonwood, [hybrid white spruce]
Cornus stolonifera (red-osier dogwood) Lonicera involucrata (black twinberry) Viburnum edule (highbush-cranberry) Rosa acicularis (prickly rose) hybrid white spruce
Herb Layer: 40% cover
Shrub Layer: 75% cover
Calamagrostis canadensis (bluejoint) Vicia americana (American vetch) Elymus glaucus (blue wildrye) Osmorhiza chilensis (mountain sweet-cicely)
[Lathyrus nevadensis (purple peavine)]
Moss Layer: 0% cover
SOIL AND SITE
Moisture Regime: 5-6 (shg-hg) Nutrient Regime: D-E (r-vr)
* Slope Gradient (%): 0 * Slope Position: valley bottom
Parent Material: fluvial Soil Texture: coarse Coarse Fragments (%): not available
DISTRIBUTION: restricted to active fluvial landforms adjacent to larger rivers
Vicia americana
56
Act - Dogwood - Prickly rose (SBSdk/08)
INTERPRETATIONS
Site limitations: - very difficult sites to manage; serious consideration should be given to managing these sites as
wildlife corridors. - sites within this unit are subject to periodic flooding; plant seedlings on naturally or artificially raised microsites.
Silviculture system:
Site preparation:
- see Section 5.1
- see Section 5.2 - creating an excessive number of mounds (eg.,
>300/ha) should be avoided, especially on sites within this unit with a water table < 30 cm from the surface.
Species choice: - Act, S x , [Pl]
Vegetation potential:
Reforestation:
- high (black twinberry, fireweed, bluejoint)
- advance regeneration should be preserved. - plant sturdy stock in groups, using available raised
microsites, rather than evenly across the site. - site could be left to regenerate naturally to Act.
Concerns: - site conditions may lead to frost damage of Sx regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) is advised.
- this association is critical to the control of runoff streamflow.
- water table will likely rise above the ground surface in spring, causing seedling mortality.
- old-growth spruce - cottonwood stands provide critical habitat, so management of these areas should be discussed with wildlife personnel.
- sites within this unit with high water tables, combined with thick organic horizons (>10 cm), increase the windthrow hazard; block layouts must have windfirm boundaries, or a wide buffer of standing timber must be left around such sites.
57
Ledum groenlandicum
Gaultheria hispidula
Sb - Creeping snowberry - Sphagnum
VEGETATION
Tree Layer: 25% cover black spruce
Shrub Layer: 50% cover Ledum groenlandicum (Labrador tea) [Betula glandulosa (scrub birch)] black spruce
Herb Layer: 20% cover Gaultheria hispidula (creeping-snowberry) [Oxycoccus oxycoccos (bog cranberry)]
Sphagnum spp. (sphagnums) Pleurozium schreberi (red-stemmed feathermoss) [Icmadophila ericetorum (spraypaint lichen)] [Cladina spp. (cladina lichens)] [Cladonia spp. (cladonia lichens)]
Moss Layer: 95% cover
SOIL AND SITE
Moisture Regime: 6-7 (hg-shd) Nutrient Regime: A-B (vp-p)
* Slope Gradient (%): 0 * Slope Position: depressions
Parent Material: organic * Soil Texture: organic
Coarse Fragments (%): 0
DISTRIBUTION: uncommon, and restricted to landscape depressions and edges of some small lakes and ponds
Sphagnum spp.
58
Sb - Creeping snowberry - Sphagnum (SBSdk/09)
INTERPRETATIONS
Site limitations: - site and soil conditions of this unit result in marginal forest productivity; serious consideration should be given to excluding logging from this unit.
Silviculture system: - avoid logging
59
Betula glandulosa
Carex disperma
Sb - Soft-leaved sedge - Sphagnum
VEGETATION
Tree Layer: 30% cover black spruce, hybrid white spruce
Shrub Layer: 35% cover [Betula glandulosa (scrub birch)] [Salix barclayi (Barclay’s willow)] [Ledum groenlandicum (Labrador tea)] [Alnus tenuifolia (mountain alder)] black spruce
Herb Layer: 75% cover Carex disperma (soft-leaved sedge) Equisetum arvense (common horsetail) Equisetum fluviatile (swamp horsetail) Potentilla palustris (marsh cinquefoil)
Moss Layer: 75% cover Tomenthypnum nitens Sphagnum spp. (sphagnums) Hylocomium splendens (step moss) [Aulacomnium palustre (glow moss)] [Drepanocladus spp. (drepanocladus mosses)] [Calliergon spp. (water mosses)] [Mnium spp. (leafy mosses)]
(golden fuzzy fen moss)
SOIL AND SITE
Moisture Regime: 6-7 (hg-shd) Nutrient Regime: C-E (m-vr)
* Slope Gradient (%): 0 * Slope Position:
Parent Material: organic * Soil Texture: organic
Coarse Fragments (%): 0
level and depressions
DISTRIBUTION: common in landscape depressions and the borders of small lakes and ponds
Potentilla palustris
60
Sb - Soft-leaved sedge - Sphagnum (SBSdk/10)
INTERPRETATIONS
Site limitations: - site and soil conditions of this unit result in marginal forest productivity; serious consideration should be given to excluding logging from this unit.
Silviculture system: - avoid logging
61
4.2 Blackwater Dry Warm Sub-Boreal Spruce 7
Location In the Prince George Forest Region the SBSdw2 occurs from just north of the Chilako River, where it borders the SBSdw3, south to the southern boundary of the region at the Blackwater River (Figure 1). Its western limit is Tatuk Lake, where it borders the SBSmc3 and its eastern boundary is the Fraser River, where it borders the SBSmh (previously SBS1) (B.C. Ministry of Forests, Cariboo Forest Region 1987). The SBSdw2 reaches its northern limit in the Prince George Region, but extends south of the Blackwater River in the Cariboo Forest Region.
Elevation Range 750 to 1100 m
Climate The SBSdw2 is dry and warm relative to other biogeoclimatic units in this guide and in the region. The SBSdw2 has the warmest climate of all the variants described in the guide (see Table 8). The warmth of this variant reflects its southern position and lower elevation with respect to the other variants. Winter precipitation is relatively low for the region, with snowpacks generally accumulating up to about 2 m in depth. Climatic growth-limiting factors are drought on drier sites and frost on frost-prone sites.
Soils, geology, and landforms Bedrock types consist mostly of Palaeozoic sedimentary rocks in the western portion of this subzone and lower Mesozoic volcanic rocks in the eastern portion. Morainal parent materials with gravelly loam and clay loam textures are predominant in this subzone and are associated with Gray Luvisols, including Brunisolic Gray Luvisols. These morainal landscapes also include components of soils formed on organic deposits (Mesisols), colluvium (Brunisolic Gray Luvisols with gravelly loam and sandy loam textures), and glaciofluvial deposits (Dystric Brunisols with gravelly sand textures). Lacustrine deposits with subdued topography occur in the eastern portion of this subzone. Gray Luvisols are associated with the finer textures (silty clay, silty clay loam), while Dystric Brunisols occur on the coarser (loamy sand) lacustrine materials.
Distinguishing the SBSdw2 from adjoining subzones/variants SBSdw3 has: • no pinegrass on mesic sites; and • queen’s cup on mesic and wetter sites. SBSmc2 has: • more subalpine fir but no Douglas-fir in the canopy; • more black huckleberry but no saskatoon in the shrub layer; and • five-leaved bramble in the herb layer but no pinegrass or wild sarsaparilla. SBSmc3 has: • no Douglas-fir or trembling aspen, but more subalpine fir in the canopy; • less saskatoon but more black huckleberry in the shrub layer; and • no pinegrass or wild sarsaparilla in the herb layer.
7 Formerly SBSk2
63
SBSmw has: • more subalpine fir in the canopy; • no pinegrass but occasional five-leaved bramble on mesic sites; and • three-leaved foamflower on moist to wet sites. SBSmh has: • infrequent occurrence of lodgepole pine in the canopy; • beaked hazelnut in the shrub layer; and • Hooker's fairybells but no pinegrass in the herb layer.
Forests The forests of the SBSdw2 are some of the most diverse in the region. Coniferous forests in this unit tend to be mixtures of lodgepole pine, Douglas- fir, and hybrid white spruce with lodgepole pine and/or Douglas-fir dominating on drier sites and hybrid white spruce dominating on wetter sites. Subalpine fir is uncommon at low elevations but increases in abundance at the higher reaches. Black spruce occurs both in wetlands as well as in combination with lodgepole pine on poorer upland sites associated with compact morainal or lacustrine soils. Upland deciduous forests are dominated by trembling aspen, and black cottonwood is common along rivers and streams.
Wildlife Douglas-fir stands in the SBSdw2 provide important winter habitat for mule deer and are used by black bear, coyote, gray wolf, and cougar. White spruce - lodgepole pine forests are used by mule deer in the summer, and are also used by moose, grizzly bear, black bear, gray wolf, wolverine, fisher, marten, and spruce grouse. Shrub-dominated wetlands below 900 m elevation provide winter habitat for moose. These wetlands also support furbearers such as beaver, muskrat, mink, and otter. Deciduous thickets and scattered open woodlands along the southern edges of this variant support a small population of sharp-tailed grouse.
64
Soil Nutrient Regime
Very Poor Poor Medium Rich Very Rich
A B C D E
Very Xeric 0
Xeric 1
Subxeric 2
Submesic 3
Mesic 4
Subhygric 5
Hygric 6
Subhydric 7
0 1 SxwFd - Pinegrass
0 2 FdPl - Cladonia 0 3 Pl- Kinnikinnick - Wavy-
04 F d - Pinegrass - Alder
05 SxwFd - Cat’s-tail moss 06 Pl- Pinegrass - Sphagnum
07 PlSb - Feathermoss
08 Sxw - Twinberry
09 Sxw - Devil’s club -
leaved moss Knight’s plume 1 0 Sxw - Horsetail
1 1 Sb - Soft-leaved sedge -
Feathermoss
FIGURE 11. Edatopic grid displaying site units in the SBSdw2 variant.
65
Site Units 02 03 04 05 06 07 01 08 09 10 11
Trees Pseudotsuga menziesii
Picea mariana
Picea glauca x engelmannii
Juniperis communis
Vaccinium myrtilloides
Amelanchier alnifolia
Shepherdia canadensis
Spiraea betulifolia
Rosa acicularis
Lonicera involucrata
Viburnum edule
Ribes triste Ledum groenlandicum
Oryzopsis p ungens
Arctostaphylos uva-ursi
Calamagrostis rubescens
Aster conspicuus
Aralia nudicaulis
Vaccinium caespitosum
Aster ciliolatus
Shrubs
p. p. 0plopanax horridus
Herbs and Dwarf Shrubs
FIGURE 12. SBSdw2 vegetation table.
Douglas-fir
black spruce
hybrid white spruce
common juniper
velvet-leaved blueberry
saskatoon
soopolallie
birch-leaved spirea
prickly rose
black twinberry
highbush-cranberry
devil’s club
red swamp currant
Labrador tea
short-awned ricegrass
kinnikinnick
pinegrass
showy aster
false sarsaparilla
dwarf blueberry
fringed aster
Prominence class:
Site Units 02 03 04 05 06 07 01 08 09 10 11
Herbs and Dwarf Shrubs
(continued) Rubus pubescens
Mitella nuda
Gymnocarpium dryopteris
Equisetum arvense
Carex spp.
Cladonia spp.
Cladina spp.
Hylocomium splendens
Rhytidiadelphus triquetrus
Mnium spp.
Sphagnum ssp.
Mosses and Lichens
FIGURE 12. SBSdw2 vegetation table (continued).
trailing raspberry
common mitrewort
oak fern common horsetail
sedges
cladonia lichens
cladina lichens
step moss
electrified cat's tail moss
leafy mosses sphagnum mosses
Prominence cl ass:
1a Mid- to upper slope or crest, or level; canopy dominated by lodgepole pine, Douglas-fir, or lodgepole pine - black spruce.
2a On crests of slopes; soils shallow (usually < 50 cm); herb layer sparse (usually < 10%).
SBSdw2/02
Mid- to upper slope, or level; soils deep (> 1 m); herb layer well developed (> 20%).
3a
2b
Canopy of lodgepole pine - black spruce; often on level sites.
SBSdw2/07
3b Black spruce absent from canopy; slope position variable.
4a Douglas-fir absent from canopy; aspect usually southerly to easterly.
SBSdw2/03
4b Douglas-fir present in canopy; aspect variable.
5a Aspect southerly; canopy dominated by Douglas-fir, sometimes with minor lodgepole pine; Juniperus communis (p. 51) 8 usually present.
SBSdw2/04
5b Aspect variable; canopy not as above; Juniperus communis usually absent.
6a Vaccinium myrtilloides (p. 43) present and generally low to moderate cover (> 2%); hybrid white spruce a minor component of the canopy, or absent.
SBSdw2/06
6b Vaccinium myrtilloides low cover (< 1%) or absent; hybrid white spruce often a major component of the canopy.
8 Page numbers refer to the publication Plants of Northern British Columbia (MacKinnon et al. 1992).
68
7a Upper slope; Lonicera involucrata (p. 48) usually absent, Betula papyrifera (paper birch) (p. 24) usually present.
SBSdw2/05
7b Mid- to upper slope or level; Lonicera involucrata usually present, Betula papyrifera usually absent.
SBSdw2/01
Mid-slope to toe, or level; canopy dominated by hybrid white spruce, or black spruce (but not black spruce - lodgepole pine).
8a Level sites; soils organic or mineral; bogs.
lb
SBSdw2/11
8b Sites level or on a slope; soils mineral.
9a Canopy of hybrid white spruce and subalpine fir; seepage water present; Equisetum spp. (pp. 281-284) moderate to high cover (> 10%).
SBSdw2/10
Subalpine fir low cover or absent in canopy; seepage water present or absent; Equisetum spp. low cover (< 5%), or absent.
10a Oplopanax horridus (p. 36) present; seepage water usually
SBSdw2/09
10b Oplopanax horridus absent; seepage water present or
9b
present.
absent.
11a Usually toe of slope, or level; Douglas-fir and lodgepole pine, if present, only minor components of the canopy.
SBSdw2/08
11b Mid- to lower slope; Douglas-fir and lodgepole pine often major components of the canopy.
SBSdw2/01
69
SxwFd - Pinegrass
Rosa acicularis
Calamagrostis rubescens
Hylocomium splendens
VEGETATION
Tree Layer: 45% cover lodgepole pine, Douglas-fir, hybrid white spruce
Shrub Layer: 30% cover Rosa acicularis (prickly rose) Spiraea betulifolia (birch-leaved spirea) Lonicera involucrata (black twinberry) Alnus crispa ssp. sinuata Amelanchier alnifolia (saskatoon) Rubus parviflorus (thimbleberry) Douglas-fir hybrid white spruce
Herb Layer: 50% cover
(Sitka alder)
Calamagrostis rubescens (pinegrass) Linnaea borealis (twinflower) Cornus canadensis (bunchberry) Arnica cordifolia (heart-leaved arnica) Orthilia secunda (one-sided wintergreen) Aralia nudicaulis (wild sarsaparilla) Fragaria virginiana (wild strawberry) Epilobium angustifolium (fireweed)
Moss Layer: 80% cover Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) Dicranum polysetum (wavy-leaved moss) Hylocomium splendens (step moss) Peltigera aphthosa (freckle lichen) Rhytidiadelphus triquetrus (electrified cat’s-tail moss)
SOIL AND SITE
Moisture Regime: 3-4 (sm-m) Nutrient Regime: B-D (p-r)
Slope Position: lower - upper, occasionally level
Parent Material: morainal or (g1acio)fluvial; occasionally lacustrine
Soil Texture: medium - very coarse Coarse Fragments (%): 0-95
Slope Gradient (%): 0-38
DISTRIBUTION: very common, widespread, and often large
70
SxwFd - Pinegrass (SBSdw2/01)
INTERPRETATIONS
Site limitations: - sites within this unit with medium- to fine-textured lacustrine soils often have poor soil structure, leading to poor root growth; plant stock that will achieve better lateral root development (eg., Cu-treated), prescribe natural regeneration, or protect advance regeneration.
Silviculture system: - see Section 5.1 - minimize or align large slash piles when logging to
help meet site preparation objectives and reduce fire hazard.
Site preparation: - see Section 5.2
Species choice: - Pl, SX, Fd
Vegetation potential:
Reforestation:
- moderate (pinegrass, fireweed, prickly rose)
- manage to maintain Fd component. - attempt natural regeneration if potential exists; if
infeasible, plant a mixture of Pl and Fd or Pl and Sx. - if Fd stems are present, conduct a stand evaluation to
assess if a partial cutting system is feasible. - i f a partial cutting system is used and abundant
advance Fd regeneration is present, attempt to log in a manner that protects this regeneration.
- fill-planting may be required with partial cuts. - help maintain stand diversity on sites to be planted
with Pl by mapping aspen patches prior to harvest and planting these areas to spruce.
Concerns: - full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (ie., lop and scatter)
- site conditions may lead to frost damage of Fd regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) is advised.
- comandra blister rust may cause cankers on pine if bastard toad-flax (Geocaulon lividum) occurs nearby.
- mountain pine beetle may cause mortality in large- diameter lodgepole pine stands of age class > 7.
- Warren’s root collar weevil can cause mortality in young stands, especially where duff layers are thick.
71
FdPl - Cladonia
VEGETATION
Tree Layer: 25% cover lodgepole pine, Douglas-fir
Shrub Layer: 15% cover Spiraea betulifolia (birch-leaved spirea) Rosa acicularis (prickly rose) [Juniperus communis (common juniper)] Douglas-fir
Herb Layer: 5% cover Calamagrostis rubescens (pinegrass) Oryzopsis pungens (short-awned ricegrass) Antennaria neglecta (field pussytoes)
Moss Layer: 70% cover Pleurozium schreberi (red-stemmed feathermoss) Polytrichum juniperinum (juniper haircap moss) Dicranum polysetum (wavy-leaved moss) Cladina spp. (cladina lichens) Cladonia spp. (cladonia lichens)
SOIL AND SITE
Moisture Regime: 1 (x) Nutrient Regime : B-C (p-m) Slope Gradient (%): 0
* Slope Position: crest * Parent Material: fluvial or morainal veneers
over bedrock Soil Texture: medium Coarse Fragments (%): 30-80
COMMENTS: based on limited data
DISTRIBUTION: uncommon, small, and usually associated with bedrock outcrops or very coarse soils
72
FdPl - Cladonia (SBSdw2/02)
INTERPRETATIONS
Site limitations: - site and soil conditions of this unit result in marginal forest productivity; serious consideration should be given to excluding logging from this unit.
- sites within this unit with high coarse fragment content (> 70%) will have significantly reduced soil moisture retention and will be extremely difficult to plant; attempt to regenerate naturally by retaining Pl cones and/or leaving Fd seed-trees on site.
Silviculture system: - see Section 5.1 - leave enough Fd stems on site to provide shade; this
reduces drying and heating of the upper soil horizons.
- light scarification for seedbed preparation if not located on xeric, crest veneer soils, or summer logging with no site preparation.
Site preparation:
Species choice: - Fd, Pl
Vegetation potential: - low
Reforestation: - manage to maintain Fd component. - if disturbance during logging does not expose some
mineral soil, then natural Pl and Fd regeneration should be promoted by either light scarification or spot screefing.
- fill-planting may be required to meet stocking requirements.
Concerns: - avoid clearcutting; stand establishment will be difficult because of high surface soil temperatures and drought.
- these units may represent important early season range for wildlife, so prescription should be discussed with wildlife personnel.
- site and soil conditions of this unit result in drought hazard for a significant portion of the growing season; leaving a shelterwood overstory can reduce the severity of the drought hazard.
- sites with shallow and/or coarse-textured soils are vulnerable to nutrient deficiency if forest floors are reduced; site preparation methods that reduce forest floor thickness, such as slashburning or brushblading, must be avoided.
- comandra blister rust may cause cankers on pine if bastard toad-flax (Geocaulon lividum) occurs nearby.
73
Vaccinium myrtilloides
Arctostaphylos uva-ursi
Pleurozium schreberi
Pl - Kinnikinnick - Wavy-leaved moss
VEGETATION
Tree Layer: 30% cover lodgepole pine, [hybrid white spruce]
Shrub Layer: 45% cover Vaccinium myrtilloides (velvet-leaved blueberry) Amelanchier alnifolia (saskatoon) Spiraea betulifolia (birch-leaved spirea) Rosa acicularis (prickly rose) Shepherdia canadensis (soopolallie) lodgepole pine
Herb Layer: 60% cover Arctostaphylos uva-ursi (kinnikinnick) Linnaea borealis (twinflower) Fragaria virginiana (wild strawberry) Aster ciliolatus (fringed aster) Calamagrostis rubescens (pinegrass) Cornus canadensis (bunchberry) Epilobium angustifolium (fireweed)
Moss Layer: 90% cover Pleurozium schreberi (red-stemmed feathermoss) Dicranum polysetum (wavy-leaved moss) Peltigera aphthosa (freckle lichen) Cladina rangiferina (grey reindeer lichen) Ptilium crista-castrensis (knight’s plume) Hylocomium splendens (step moss)
SOIL AND SITE
Moisture Regime: 2 (sx) Nutrient Regime: A-B (vp-p) Slope Gradient (%): 10-35 Slope Position: mid-crest or level
* Aspect: southerly to easterly Parent Material: glaciofluvial
* Soil Texture: coarse Coarse Fragments (%): 45-54
DISTRIBUTION: common adjacent to larger rivers on upper terraces or on old glacial meltwater channels with deposits of coarse soils
74
Pl - Kinnikinnick - Wavy-leaved moss (SBSdw2/03)
INTERPRETATIONS
Site limitations: - site and soil conditions of this unit result in marginal forest productivity; serious consideration should be given to excluding logging from this unit.
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
Site preparation: - light scarification for seedbed preparation, or summer logging with no site preparation.
Species choice: - Pl, Fd
Vegetation potential: - low
Reforestation: - attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant Pl. - Fd may be planted on moister microsites.
- full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (ie., lop and scatter)
- site and soil conditions of this unit result in drought hazard for a significant portion of the growing season; natural regeneration is generally more adapted to surviving these conditions, especially during establishment.
- sites with shallow and/or coarse-textured soils are vulnerable to nutrient deficiency if forest floors are reduced; site preparation methods that reduce forest floor thickness, such as slashburning or brushblading, must be avoided.
- comandra blister rust may cause cankers on pine if bastard toad-flax (Geocaulon lividum) occurs nearby.
Concerns:
75
Fd - Pinegrass - Aster
Shepherdia canadensis
Arctostaphylos uva-ursi
VEGETATION
Tree Layer: 30% cover
Shrub Layer: 20% cover
Douglas-fir, [lodgepole pine]
Shepherdia canadensis (soopolallie) Rosa acicularis (prickly rose) Amelanchier alnifolia (saskatoon)
1 Juniperus communis (common juniper) Douglas-fir
Achillea millefolium (yarrow) Calamagrostis rubescens (pinegrass) Arctostaphylos uva-ursi (kinnikinnick) Solidago spathulata (spike-like goldenrod) Fragaria virginiana (wild strawberry) Lathyrus ochroleucus (creamy peavine) Aster conspicuus (showy aster) Galium boreale (northern bedstraw) Vicia americana (American vetch) Disporum trachycarpum (rough-fruited fairy bells)
Herb Layer: 35% cover
Moss Layer: 15% cover Pleurozium schreberi (red-stemmed feathermoss) Dicranum polysetum (wavy-leaved moss) Peltigera spp. (peltigera lichens)
SOIL AND SITE
Moisture Regime: 2 (sx) Nutrient Regime: B-D (p-r)
Parent Material: glaciofluvial - colluvial Soil Texture: medium to coarse Coarse Fragments (%): 30-54
* Aspect: southerly (SE-SW)
* Slope Gradient (%): 33-104 * Slope Position: mid - upper
DISTRIBUTION: uncommon, generally small, on moderate to very steep warm aspects
Dicranum polysetum
76
Fd - Pinegrass - Aster (SBSdw2/04)
INTERPRETATIONS
Site limitations: - sites within this unit with high coarse fragment content (> 70%) will have significantly reduced soil moisture retention and will be extremely difficult to plant; attempt to regenerate naturally by retaining Pl cones and/or leaving Fd seed-trees on site.
Silviculture system: - see Section 5.1 - enough Fd stems should be left to provide shade to
the site, thereby reducing excessive drying and heating of the upper soil horizons.
- if a partial cutting system is used, refer to Cariboo Region mule deer guidelines (Land Management Handbook #13).
Site preparation: - light scarification for seedbed preparation, or summer logging with no site preparation.
Species choice: - Fd, Pl
Vegetation potential: - low
Reforestation: - manage to maintain Fd component. - if disturbance during logging does not expose some
mineral soil, then natural Pl and Fd regeneration should be promoted by light scarification or spot screefing.
- fill-planting may be required to meet stocking requirements.
Concerns: - these units may represent important early season range for wildlife, so prescription should be discussed with wildlife personnel.
- site and soil conditions of this unit result in drought hazard for a significant portion of the growing season; leaving a shelterwood overstory can reduce the severity of the drought hazard.
77
SxwFd - Cat’s-tail moss
Rosa acicularis
Hylocomium splendens
Rhytidiadelphus
triquetrus
VEGETATION
Tree Layer: 45% cover Douglas-fir, hybrid white spruce, lodgepole pine, paper birch
Shrub Layer: 15% cover I Rosa acicularis (prickly rose)
Spiraea betulifolia (birch-leaved spirea) Amelanchier alnifolia (saskatoon) Viburnum edule (highbush-cranberry) Douglas-fir
Herb Layer: 20% cover Linnaea borealis (twinflower) Orthilia secunda (one-sided wintergreen) Aralia nudicaulis (wild sarsaparilla) Cornus canadensis (bunchberry) Arnica cordifolia (heart-leaved arnica) Fragaria virginiana (wild strawberry) Geocaulon lividum (bastard toad-flax) Mitella nuda (common mitrewort)
Moss Layer: 90% cover Pleurozium schreberi (red-stemmed feathermoss) Hylocomium splendens (step moss) Ptilium crista-castrensis (knight’s plume) Rhytidiadelphus triquetrus (electrified cat’s-tail moss) Peltigera aphthosa (freckle lichen) Dicranum polysetum (wavy-leaved moss)
SOIL AND SITE
Moisture Regime: 3 (sm) Nutrient Regime: A-C (vp-m)
* Slope Position: upper * Slope Gradient (%): 55-68
Parent Material: colluvial, morainal, or glaciofluvial
Soil Texture: medium - very coarse Coarse Fragments (%): 9-50
* Aspect: usually northerly
COMMENTS: based on limited data
DISTRIBUTION: uncommon, on moderate to steep cool asp e c t s
78
SxwFd - Cat’s-tail moss (SBSdw2/05)
INTERPRETATIONS
Site limitations: - sites within this unit with high coarse fragment content (> 70%) will have significantly reduced soil moisture retention and will be extremely difficult to plant; attempt to regenerate naturally by retaining Pl cones and/or leaving Fd seed-trees on site.
Silviculture system: - see Section 5.1 - if a partial cutting system is used, refer to Cariboo
Region mule deer guidelines (Land Management Handbook #13).
Site preparation: - see Section 5.2
Species choice: - Fd, Pl
Vegetation potential: - low
Reforestation: - manage to maintain Fd component. - retain enough Fd stems to provide seed to as much of
- natural Pl and Fd regeneration should be promoted
- fill-planting may be required to meet stocking
the site as possible.
by light scarification or spot screefing.
requirements.
Concerns: - site and soil conditions of this unit result in drought hazard for a significant portion of the growing season; leaving a shelterwood overstory can reduce the severity of the drought hazard.
- comandra blister rust may cause cankers on pine if bastard toad-flax (Geocaulon lividum) occurs nearby.
79
Pl - Pinegrass - Feathermoss
Vaccinium myrtilloides
Arctostaphylos uva-ursi
Pleurozium schreberi
VEGETATION
Tree Layer: 15% cover lodgepole pine, Douglas-fir
Shrub Layer: 45% cover Vaccinium myrtilloides (velvet-leaved blueberry) Rosa acicularis (prickly rose) Spiraea betulifolia (birch-leaved spirea) Alnus crispa ssp. sinuata (Sitka alder) Amelanchier alnifolia (saskatoon) Douglas-fir trembling aspen
Herb Layer: 60% cover Calamagrostis rubescens (pinegrass) Linnaea borealis (twinflower) Arctostaphylos uva-ursi (kinnikinnick) Epilobium angustifolium (fireweed) Chimaphila umbellata (prince's pine) Fragaria virginiana (wild strawberry) Achillea millefolium (yarrow) Cornus canadensis (bunchberry) Orthilia secunda (one -sided wintergreen)
Moss Layer: 80% cover Pleurozium schreberi (red-stemmed feathermoss) Dicranum polysetum (wavy-leaved moss) Ptilium crista-castrensis (knight's plume) Hylocomium splendens (step moss) Peltigera aphthosa (freckle lichen)
SOIL AND SITE
Moisture Regime: 3 (sm) Nutrient Regime: A-D (p-r)
Slope Position: mid - upper slope, occasionally level
Parent Material: morainal, lacustrine, or (glacio)fluvial; occasionally colluvial medium - very coarse
Slope Gradient (%): 0-65
Soil Texture: Coarse Fragments (%): 0-75
DISTRIBUTION: common, widespread, and often large
80
Pl - Pinegrass - Feathermoss (SBSdw2/06)
INTERPRETATIONS
Site limitations: - sites within this unit with high coarse fragment content (> 70%) will have significantly reduced soil moisture retention and will be extremely difficult to plant; attempt to regenerate naturally by retaining Pl cones and/or leaving Fd seed-trees on site.
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
- if a partial cutting system is used, refer to Cariboo Region mule deer guidelines (Land Management Handbook #13).
Site preparation: - light scarification for seedbed preparation or summer logging with no site preparation
Species choice: - Pl, Fd, SX
Vegetation potential:
Reforestation:
- low to moderate (pinegrass, fireweed, prickly rose)
- attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant Pl. - if Fd stems are present, conduct a stand evaluation to
assess if a partial cutting system is feasible. - if abundant advance regeneration is present, attempt
to log in a manner that protects this regeneration. - fill-planting may be required to meet stocking
requirements if a partial cutting system is used. - Sx may be planted on moister microsites.
- full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (ie., lop and scatter).
- site conditions may lead to frost damage of Fd regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) is advised.
- comandra blister rust may cause cankers on pine if bastard toad-flax (Geocaulon lividum) occurs nearby.
- mountain pine beetle may cause mortality in large- diameter lodgepole pine stands of age class > 7.
Concerns:
81
PlSb - Feathermoss
Vaccinium myrtilloides
Geocaulum lividum
Pleurozium schreberi
VEGETATION
Tree Layer: 25% cover lodgepole pine, black spruce, hybrid white spruce
Shrub Layer: 60% cover Vaccinium myrtilloides (velvet-leaved blueberry) Rosa acicularis (prickly rose) Spiraea betulifolia (birch-leaved spirea) black spruce lodgepole pine hybrid white spruce
Herb Layer: 55% cover Calamagrostis rubescens (pinegrass) Cornus canadensis (bunchberry) Epilobium angustifolium (fireweed) Linnaea borealis (twinflower) Geocaulon lividum (bastard toad-flax) Fragaria virginiana (wild strawberry) Vaccinium caespitosum (dwarf blueberry) Aster ciliolatus (fringed aster) Arnica. cordifolia (heart-leaved arnica)
Moss Layer: 95% cover Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight's plume) Hylocomium splendens (step moss) Dicranum polysetum (wavy-leaved moss) Peltigera aphthosa (freckle lichen)
SOIL AND SITE
Moisture Regime: 3-5 (sm-shg) Nutrient Regime: A-B (vp-p)
* Slope Gradient (%): 0-4 (usually 0)
* Slope Position: level or mid-slope Parent Material: lacustrine, morainal or
glaciofluvial Soil Texture: fine - medium - coarse Coarse Fragments (%): 0-30
DISTRIBUTION: uncommon, often in areas of cold air accumulation or with poor air drainage and cold soils
82
PlSb - Feathermoss (SBSdw2/07)
INTERPRETATIONS
Site limitations: - compact soil layers and/or low aeration porosity associated with fine-textured soils will have a reduced root zone and decreased productivity over a rotation; regenerate naturally whenever possible.
- soils are saturated in the spring, but may experience drought in summer, both resulting in poor root development; the poor productivity resulting from these limitations should dictate a limited intensive silvicultural investment.
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
Site preparation: - see Section 5.2
Species choice: - Pl, (SX, Sb)
Vegetation potential: - low
Reforestation: - attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant Pl. - Sx and Sb are generally significantly less productive
than Pl on this unit.
Concerns: - full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (ie., lop and scatter).
- site conditions may lead to frost damage of Sx regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) is advised.
- comandra blister rust may cause cankers on pine if bastard toad-flax (Geocaulon lividum) occurs nearby.
- mountain pine beetle may cause mortality in large- diameter lodgepole pine stands of age class > 7.
- Warren’s root collar weevil can cause mortality in young stands, especially where duff layers are thick.
83
Sxw - Twinberry
Lonicera involucrata
Rubus pubescens
Petasites frigidus
var. palmatus
VEGETATION
Tree Layer: 40% cover hybrid white spruce, [trembling aspen]
Shrub Layer: 35% cover Lonicera involucrata (black twinberry) Rosa acicularis (prickly rose) Viburnum edule (highbush-cranberry) Ribes lacustre (black gooseberry) Amelanchier alnifolia (saskatoon) hybrid white spruce
Herb Layer: 50% cover Cornus canadensis (bunchberry) Rubus pubescens (trailing raspberry) Mitella nuda (common mitrewort) Osmorhiza chilensis (mountain sweet-cicely) Petasites frigidus var. palmatus (palmate coltsfoot) Linnaea borealis (twinflower) Equisetum arvense (common horsetail) Aralia nudicaulis (wild sarsaparilla) Pyrola asarifolia (pink wintergreen) Aster ciliolatus (fringed aster)
Moss Layer: 75% cover Rhytidiadelphus triquetrus (electrified cat’s-tail moss) Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) Hylocomium splendens (step moss) Mnium spp. (leafy mosses)
SOIL AND SITE
Moisture Regime: 5-6 (shg-hg) Nutrient Regime: B-D (p-r)
* Slope Gradient (%): * Slope Position:
Parent Material: variable Soil Texture: Coarse Fragments (%): 0-64 Seepage Water: sometimes present
0-65 (usually < 10) (mid) - toe or level
(coarse -) medium - fine
DISTRIBUTION: common, generally small, and often associated with streams
84
Sxw - Twinberry (SBSdw2/08)
INTERPRETATIONS
Site limitations: - sites within this unit with medium- to fine-textured lacustrine soils often have poor soil structure, leading to poor root growth; plant stock that will achieve better lateral root development (eg., Cu-treated), prescribe natural regeneration, or protect advance regeneration.
- sites within this unit with saturated soils are poorly aerated, which slows root development; plant seedlings on naturally or artificially raised microsites.
- see Section 5.1
- see Section 5.2
Silviculture system:
Site preparation:
Species choice: - Pl, SX, Fd, [Bl]
Vegetation potential:
Reforestation:
- moderate (black twinberry, fireweed)
- preserve vigorous advance Fd or Sx regeneration when feasible.
- plant sturdy stock as soon after harvesting as possible.
- fill-planting will likely be required if stand is partially cut.
- help maintain stand diversity on sites to be planted with Pl by mapping aspen patches prior to harvest and planting these areas to spruce.
- young Bl regeneration (< 3 m tall) may be susceptible to heavy browsing by moose.
Concerns: - site conditions may lead to frost damage of Fd, Sx, and Bl regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost- resistant species (eg., Pl) is advised.
- sites within this unit with silty soils are susceptible to frost-heaving; bareroot stock will likely resist frost-heaving better than plug stock.
- sites within this unit with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations or dry soil conditions.
- Warren’s root collar weevil can cause mortality in young stands, especially where duff layers are thick.
85
Sxw - Devil’s club - Knight’s plume
Oplopanax horridus
Gymnocarpium
dryopteris
Dryopteris expansa
VEGETATION
Tree Layer: 15% cover hybrid white spruce, Douglas-fir, lodgepole pine, subalpine fir
Shrub Layer: 25% cover Oplopanax horridus (devil’s club) Ribes lacustre (black gooseberry) Lonicera involucrata (black twinberry) Alnus tenuifolia (mountain alder) Rosa acicularis (prickly rose) Acer glabrum (Douglas maple) Ribes triste (red swamp currant) subalpine fir hybrid white spruce
Herb Layer: 30% cover Gymnocarpium dryopteris (oak fern) Dryopteris expansa (spiny wood fern) Streptopus amplexifolius (clasping twistedstalk) Galium triflorum (sweet-scented bedstraw) Mitella nuda (common mitrewort) Athyrium filix-femina (lady fern)
Cornus canadensis (bunchberry) Rubus pedatus (five-leaved bramble)
Moss Layer: 40% cover Ptilium crista-castrensis (knight’s plume) Mnium spp. (leafy mosses) Pleurozium schreberi (red-stemmed feathermoss) Rhytidiadelphus triquetrus (electrified cat’s-tail moss)
Peltigera spp. (peltigera lichens)
SOIL AND SITE
Moisture Regime: 5-6 (shg-hg) Nutrient Regime: C-E (m-vr)
(mid) - toe Slope Gradient (%): 2-28
Parent Material: fluvial or morainal Soil Texture: fine - medium Coarse Fragments (%): 13-26
* Seepage Water: usually present
* Slope Position:
DISTRIBUTION: rare, generally small, and found on cool (north) seepage slopes
86
Sxw - Devil’s club - Knight’s plume (SBSdw2/09)
INTERPRETATIONS
Site limitations: - sites within this unit with saturated soils are poorly aerated, which slows root development; plant seedlings on naturally or artificially raised microsites.
Silviculture system:
Site preparation:
- see Section 5.1
- see Section 5.2
Species choice: - Pl, SX, Fd, [Bl]
Vegetation potential:
Reforestation:
- high (black twinberry, fireweed, mountain alder)
- preserve vigorous advance Fd or Sx regeneration
- plant sturdy stock as soon after harvesting as
- plant Fd on raised microsites if water table within 50
- young Bl regeneration ( < 3 m tall) may be susceptible
- fill-planting will likely be required if stand is
when feasible.
possible.
cm of surface.
to heavy browsing by moose.
partially cut.
Concerns: - site conditions may lead to frost damage of Fd, Sx, and Bl regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost- resistant species (eg., Pl) is advised.
- sites within this unit with silty soils are susceptible to frost-heaving; bareroot stock will likely resist frost-heaving better than plug stock.
- sites within this unit with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations or dry soil conditions.
- sites within this unit with high water tables, combined with thick organic horizons (> 10 cm), increase the windthrow hazard; block layouts must have windfirm boundaries, or a wide buffer of standing timber must be left around such sites.
- Warren’s root collar weevil can cause mortality in young stands, especially where duff layers are thick.
87
Sxw - Horsetail
Lonicera involucrata
Ribes triste
Equisetum arvense
VEGETATION
Tree Layer: 30% cover hybrid white spruce, subalpine fir
Shrub Layer: 30% cover Lonicera involucrata (black twinberry) Rosa acicularis (prickly rose) Ribes triste (red swamp currant) Ribes lacustre (black gooseberry) Viburnum edule (highbush-cranberry) Cornus stolonifera (red-osier dogwood) hybrid white spruce
Herb Layer: 80% cover Cornus canadensis (bunchberry) Petasites frigidus var. palmatus (palmate coltsfoot) Linnaea borealis (twinflower) Mitella nuda (common mitrewort) Galium triflorum (sweet-scented bedstraw) Equisetum arvense (common horsetail) Equisetum palustre (marsh horsetail) Equisetum sylvaticum (wood horsetail) Rubus pubescens (trailing raspberry) Gymnocarpium dryopteris (oak fern) Heracleum lanatum (cow-parsnip) Streptopus amplexifolius (clasping twistedstalk) Osmorhiza chilensis (mountain sweet-cicely)
Moss Layer: 85% cover Pleurozium schreberi (red-stemmed feathermoss) Hylocomium splendens (step moss) Ptilium crista-castrensis (knight’s plume) Rhytidiadelphus triquetrus (electrified cat’s-tail moss) [Mnium spp. (leafy mosses)]
SOIL AND SITE
Moisture Regime: 6 (hg) Nutrient Regime: C-E (m-vr)
* Slope Gradient (%): 0-8 * Slope Position: * Parent Material: fluvial
Soil Texture: variable, usually fine Coarse Fragments (%): 0-5
toe - level
* Seepage Water: present
DISTRIBUTION: common; associated with watercourses
88
Sxw - Horsetail (SBSdw2/10)
INTERPRETATIONS
Site limitations: - very difficult sites to manage; serious consideration should be given to managing these sites as wildlife corridors.
- sites within this unit with saturated soils are poorly aerated, which slows root development; plant seedlings on naturally or artificially raised microsites.
Silviculture system:
Site preparation:
- see Section 5.1
- see Section 5.2 - creating an excessive number of mounds (eg.,
>300/ha) should be avoided, especially on sites within this unit with a water table < 30 cm from the surface.
Species choice:
Vegetation potential:
Reforestation:
- S x , [Pl, Bl]
- high (black twinberry, fireweed, bluejoint)
- advance regeneration should be preserved. - supplement advance regeneration by planting sturdy
stock in groups, using available raised microsites. - young Bl regeneration (< 3 m tall) may be susceptible
to heavy browsing by moose.
Concerns: - site conditions may lead to frost damage of Sx and Bl regeneration, especially in any naturally occurring or artificially created depression; leaving a partial
canopy and/or choosing a frost-resistant species (eg., Pl) is advised.
- sites within this unit with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations or dry soil conditions.
- sites within this unit with high water tables, combined with thick organic horizons (> 10 cm), increase the windthrow hazard; block layouts must have windfirm boundaries, or a wide buffer of standing timber must be left around such sites.
- these units may represent important wildlife habitat; discuss prescription with wildlife personnel.
- water table will likely rise above the ground surface in the spring, causing seedling mortality.
- this association is critical to the control of runoff streamflow.
- Warren’s root collar weevil can cause mortality in young stands, especially where duff layers are thick.
89
Ledum groenlandicum
Carex disperma
Equisetum arvense
Sb - Soft-leaved sedge - Sphagnum
VEGETATION
Tree Layer: 5% cover black spruce, hybrid white spruce
Shrub Layer: 25% cover Ledum groenlandicum (Labrador tea) Lonicera involucrata (black twinberry) Rosa acicularis (prickly rose) Salix spp. (willows) Ribes hudsonianum (northern black currant) Ribes lacustre (black gooseberry)
I Ribes triste (red swamp currant)
Herb Layer: 90% cover Carex leptalea (bristle-stalked sedge) Carex disperma (soft-leaved sedge) Equisetum arvense (common horsetail) Equisetum scirpoides (dwarf scouring-rush)
Mitella nuda (common mitrewort) Linnaea borealis Petasites frigidus var. palmatus (palmate coltsfoot) Epilobium angustifolium (fireweed) Geocaulon lividum (bastard toad-flax)
Cornus canadensis (bunchberry)
(twinflower) ’
Moss Layer: 95% cover Hylocomium splendens (step moss) Ptilium crista-castrensis (knight’s plume) Sphagnum spp. (sphagnums) Pleurozium schreberi (red-stemmed feathermoss) Rhytidiadelphus triquetrus (electrified cat’s-tail moss) Mnium spp. (leafy mosses) Aulacomnium palustre (glow moss)
SOIL AND SITE
Moisture Regime: 6-7 (hg-shd)
Slope Gradient (%): 0-1
Soil Texture: medium or organic Coarse Fragments (%): 0-34
Nutrient Regime: B-C (p-m)
* Slope Position: * Parent Material:
toe, level, or depression fluvial or organic
* Seepage Water: present, near the surface
DISTRIBUTION: common, in wet, cold air accumulation sites
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Sb - Soft-leaved sedge - Sphagnum (SBSdw2/11)
INTERPRETATIONS
Site limitations: - site and soil conditions of this unit result in marginal forest productivity; serious consideration should be given to excluding logging from this unit.
Silviculture system: - avoid logging
91
4.3
Location The SBSdw3 occurs northward from its border with the SBSdw2 to the confluence of the Nechako and Fraser rivers. From there it stretches northwest to Stuart Lake where it bulges north to about Inzana Lake and west to the western ends of Stuart and Trembleur lakes.
Elevation Range 750 to 1100 m
Climate The SBSdw3 is warm relative to other biogeoclimatic units in this guide and region. Winter precipitation is relatively low for the subzone with snowpacks generally accumulating up to about 2 m in depth. Climatic growth-limiting factors are drought on drier sites and frost on frost-prone sites.
Soils, geology, and landforms North of Vanderhoof, bedrock types in this subzone include Palaeozoic limestones, chert, argillite, and various volcanic and metamorphic rocks. South and east of Vanderhoof, the dominant bedrock types are volcanics of Triassic, Jurassic, and Tertiary age, and a variety of Palaeozoic sedimentary rocks. Soils have formed on predominantly morainal and lacustrine materials. Morainal deposits usually have gravelly clay loam and loam textures, associated with Gray Luvisolic soils, including Brunisolic Gray Luvisols. Dystric Brunisols have formed on coarser (gravelly sandy loam) morainal materials. Organic soils (Fibrisols) occur as a minor component of morainal landscapes. Lacustrine deposits have fine textures, ranging from silt loam to heavy clay, and Gray Luvisolic soils. Minor areas of glaciofluvial materials are coarser-textured (gravelly sand) and associated with Dystric Brunisols.
Distinguishing the SBSdw3 from adjoining biogeoclimatic units SBSdw2 has: • pinegrass on mesic sites; and • no queen’s cup on mesic and wetter sites. SBSmc2 has: • more subalpine fir but no Douglas-fir in the canopy; • more black huckleberry but no saskatoon in the shrub layer; and • five-leaved bramble but no wild sarsaparilla in the herb layer. SBSmc3 has: • more subalpine fir but no Douglas-fir or trembling aspen in the canopy; • more black huckleberry but no saskatoon in the shrub layer; and • no wild sarsaparilla in the herb layer. SBSmw has: • more subalpine fir in the canopy; • occasional five-leaved bramble on mesic sites; and • three-leaved foamflower on moist to wet sites.
Stuart Dry Warm Sub-Boreal Spruce 9
9 Formerly SBSk3
92
SBSmh has: • infrequent occurrence of lodgepole pine in the canopy; • beaked hazelnut in the shrub layer; and • Hooker’s fairybells in the herb layer.
Forests The forests of the SBSdw3 are some of the most diverse in the region. Coniferous forests in this unit tend to be mixtures of lodgepole pine, Douglas- fir, and hybrid white spruce with lodgepole pine and/or Douglas-fir dominating on drier sites and hybrid white spruce dominating on wetter sites. Subalpine fir is uncommon at low elevation, but increases in abundance at the higher reaches. Black spruce occurs in wetlands, and in combination with lodgepole pine on poorer upland sites associated with compact morainal or lacustrine soils. Deciduous forests are most commonly dominated by trembling aspen, but localized paper birch forests do exist, especially near Prince George and Fort St. James. Black cottonwood is common along rivers and streams.
Wildlife The SBSdw3 supports a wide variety of wildlife. Douglas-fir stands provide important winter habitat for mule deer, and early spring habitat for black bear. South-facing slopes along the Stuart and Nechako rivers are used in the winter by a small population of elk. Riparian forests are used in the early spring by black bear and grizzly bear. This habitat is also used by moose, white-tailed deer, lynx and ruffed grouse. Shrub-dominated wetlands support beaver, muskrat, mink, otter, northern harrier, and, in some areas, sandhill cranes. Habitat in and around small lakes is used by moose, gray wolf, beaver, muskrat, mink, otter and birds such as osprey, bald eagle, and cavity nesters. White spruce - lodgepole pine forests are used by moose, grizzly bear, black bear, spruce grouse, northern goshawk, and furbearers, including wolverine, marten, and red squirrel.
93
Soil Nutrient Regime
Very Poor Poor Medium Rich Very Rich
A B C D E
Very Xeric 0
Xeric 1
Subxeric 2
Submesic 3
Mesic 4
Subhygric 5
Hygric 6
Subhydric 7
01 SxwFd - Pinegrass
02 FdPl - Cladonia
03 Pl - Feathermoss - Cladina
04 SxwFd - Ricegrass moss 05 PlSb - Feathermoss 06 Sxw - Pink spirea - Prickly
07 Sxw - Twinberry 08 Sxw - Oak fern
09 Sxw - Horsetail - Glow
10 Sb - Soft-leaved sedge - Sphagnum
rose
FIGURE 13. Edatopic grid displaying site units in the SBSdw3 variant.
94
Site Units 02 03 04 05 01 06 07 08 09 10
Trees
Pseudotsuga menziesii
Picea mariana
Picea glauca x engelmannii
Rosa acicularis
Spiraea betulifolia
Alnus crispa ssp. sinuata
Spiraea douglassi ssp. menziesii
Lonicera involucrata
Cornus canadensis
Linnaea borealis
Arctostaphylos uva-ursi
Oryzopsis asperifolia
Chimaphila umbellata
Clintonia uniflora
Vaccinium caespitosum
Petasites frigidus var . palmatus
Gymnocarpum dryopteris
Equisetum arvense
Carex spp.
Cladina rangiferina
Sphagnum spp.
Shrubs
Herbs and Dwarf Shrubs
Mosses and Lichens
Douglas-fir
black spruce
hybrid white spruce
prickly rose
birch-leaved spirea
Sitka alder
pink spirea
black twinberry
bunchberry
twinflower
kinnikinnick
rough-leaved ricegrass
prince’s pine
queen’s cup
dwarf blueberry
palmate coltsfoot
oak fern
common horsetail
sedges
grey reindeer lichen
sphagnum mosses
FIGURE 14. SRSdw3 vegetation table. Prominence class:
1a Black spruce or tamarack present in canopy.
2a Pure black spruce canopy or mixture of black spruce and tamarack; Sphagnum spp. (pp. 312-314) 10 present; organic soils.
SBSdw3/10
Mixed stand of black spruce and hybrid white spruce or black spruce and lodgepole pine; Sphagnum spp. present or absent; mineral or organic soils.
3a Hybrid white spruce and black spruce canopy; level or depression; no mineral soil within 40 cm of surface; often adjacent to bogs; Equisetum spp. (pp. 281-284) abundant.
2b
SBSdw3/09
Predominantly lodgepole pine canopy with black spruce; gently sloping or level; mineral soils; Equisetum spp. low cover (< 1%) or absent.
SBSdw3/05
3b
1b Black spruce absent from canopy.
4a Canopy dominated by Douglas-fir.
5a Shallow soils over bedrock or colluvial soils; upper slope or crest; Arctostaphylos uva-ursi (p. 82) moderate cover (usually > 5%).
SBSdw3/02
5b Deep soils (>1 m); slope position variable; Arctostaphylos uva-ursi generally low cover (< 5%) or absent.
6a Mid- to lower slope or level; soils variable; Clintonia uniflora (p. 131) common, Rubus parviflorus (p. 36) or Lonicera involucrata (p. 48) present.
SBSdw3/01
Mid- to upper slope; moderately coarse to coarse-textured soils; Clintonia uniflora, Rubus parviflorus and Lonicera involucrata generally low cover (< 1% each) or absent.
6b
SBSdw3/04
4b Canopy dominated by hybrid white spruce or lodgepole pine.
10 Page numbers refer to the publication Plants of Northern British Columbia (MacKinnon et al. 1992)
96
7a Canopy pure lodgepole pine; level; coarse-textured fluvial material; Arctostaphylos uva-ursi common.
SBSdw3/03
Canopy generally mixed; soils variable; Arctostaphylos uva-ursi not common.
8a
7b
Lower to toe slope, depression or level (midslope only if north-facing); Equisetum spp. (pp. 281-284), Gymnocarpium dryopteris (p. 293) or Petasites frigidus var. palmatus (p. 114) abundant.
9a Trembling aspen often present in canopy; soil texture variable; Petasites frigidus var. palmatus or Equisetum spp. abundant, Gymnocarpium dryopteris low cover (< 5%) or absent.
10a Equisetum spp. common; adjacent to flowing
SBSdw3/09
10b Equisetum spp. low cover or absent; generally
water or bog.
not adjacent to flowing water or bog.
11a Generally lodgepole pine - aspen canopy; moderately fine to fine textured lacustrine soils; Spiraea douglasii ssp. menziesii (p. 45) present.
SBSdw3/06
11b Generally hybrid white spruce or hybrid white spruce - aspen canopy; soils variable; Spiraea douglasii ssp. menziesii absent.
SBSdw3/07
9b Trembling aspen generally absent from canopy; usually moderately coarse to coarse-textured soils; Gymnocarpium dryopteris abundant.
SBSdw3/08
8b Mid- to upper slope; Equisetum spp., Gymnocarpium dryopteris and Petasites frigidus var. palmatus low cover (< 1%) or absent.
12a Mid- to lower slope or level; soils variable; Clintonia uniflora common, Rubus parviflorus or Lonicera involucrata present.
SBSdw3/01
12b Mid- to upper slope; moderately coarse to coarse- textured soils; Clintonia uniflora, Rubus parviflorus and Lonicera involucrata generally low cover (< 1% each) or absent.
SBSdw3/04
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Spiraea betulifolia
Clintonia uniflora
Aster conspicuus
SxwFd - Pinegrass
VEGETATION
Tree Layer: 40% cover lodgepole pine, hybrid white spruce, Douglas-fir
Shrub Layer: 35% cover Spiraea betulifolia (birch-leaved spirea) Rosa acicularis (prickly rose) Viburnum edule (highbush-cranberry) Lonicera involucrata (black twinberry) Rubus parviflorus (thimbleberry) [Alnus crispa ssp. sinuata hybrid white spruce
Herb Layer: 40% cover Cornus canadensis (bunchberry) Clintonia uniflora (queen’s cup) Aster conspicuus (showy aster) Linnaea borealis (twinflower) Amica cordifolia (heart-leaved arnica) Smilacina racemosa (false Solomon’s-seal)
(Sitka alder)]
Moss Layer: 90% cover Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume)
SOIL AND SITE
Moisture Regime: 4 (m) Nutrient Regime: B-D (p-r) Slope Gradient (%): 0-30
* Slope Position: mid ( - lower) or upper with northerly aspect
Parent Material: variable Soil Texture: variable Coarse Fragments (%): 0-65
COMMENTS: the abundance of Sitka alder is variable
DISTRIBUTION: very common and widespread
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SxwFd - Pinegrass (SBSdw3/01)
INTERPRETATIONS
Site limitations: - sites within this unit with medium- to fine-textured lacustrine soils often have poor soil structure, leading to poor root growth; plant stock that will achieve better lateral root development (eg., Cu-treated), prescribe natural regeneration, or protect advance regeneration.
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
Site preparation: - see Section 5.2
Species choice: - Pl, SX, Fd
Vegetation Potential: - low to moderate (trembling aspen, fireweed, prickly rose)
Reforestation: - manage to maintain Fd component. - attempt to regenerate naturally if potential exists. - if abundant advance regeneration is present, attempt
to log in a manner that protects this regeneration. - fill-planting may be required to meet stocking
requirements if a partial cutting system is used. - help maintain stand diversity on sites to be planted
with Pl by mapping aspen patches prior to harvest and planting these areas to spruce.
- young Bl regeneration (< 3 m tall) may be susceptible to heavy browsing by moose.
Concerns: - full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (ie., lop and scatter).
- site conditions may lead to frost damage of Fd and Sx regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) is advised.
- risk of windthrow after partial cuts will be high on sites with root-restricting layers at depths < 25 cm.
- comandra blister rust may cause cankers on pine if bastard toad-flax (Geocaulon lividum) occurs nearby.
- mountain pine beetle may cause mortality in large- diameter lodgepole pine stands of age class > 7.
99
FdPl - Cladonia
Spiraea betulifolia
Arctostaphylos uva-ursi
Peltigera malacea
VEGETATION
Tree Layer: 30% cover Douglas-fir, lodgepole pine
Shrub Layer: 25% cover Spiraea betulifolia (birch-leaved spirea) Shepherdia canadensis (soopolallie) Rosa acicularis (prickly rose) Amelanchier alnifolia (saskatoon) Vaccinium membranaceum (black huckleberry) Douglas-fir hybrid white spruce
Herb Layer: 40% cover Arctostaphylos uva-ursi (kinnikinnick) Linnaea borealis (twinflower) Disporum trachycarpum (rough-fruited fairybells) Vaccinium caespitosum (dwarf blueberry) Oryzopsis asperifolia (rough-leaved ricegrass) Cornus canadensis (bunchberry) Antennaria neglecta (field pussytoes)
Peltigera malacea (apple pelt) Cladina rangiferina (grey reindeer lichen) Pleurozium schreberi (red-stemmed feathermoss) Dicranum polysetum (wavy-leaved moss) Cladonia phyllophora (black-foot cladonia) Cladonia ecmocyna (orange-foot lichen)
Moss Layer: 50% cover
SOIL AND SITE
Moisture Regime: 1-2 (x-sx) Nutrient Regime: B-C (p-m)
* Aspect: southerly
* Slope Position: * Slope Gradient (%): 10-40
(mid -) upper - crest
bedrock medium - coarse (only medium textured on shallow soils)
Coarse Fragments (%): 12-85
Parent Material: variable; often shallow to
Soil Texture:
DISTRIBUTION: uncommon; restricted to south-facing coarse-textured eskers or sites with bedrock close to surface
100
FdPl - Cladonia (SBSdw3/02)
INTERPRETATIONS
Site limitations: - sites within this unit with high coarse fragment content (> 70%) will have significantly reduced soil moisture retention and will be extremely difficult to plant; attempt to regenerate naturally by retaining Pl cones and/or leaving Fd seed-trees on site.
Silviculture system:
Site preparation:
- see Section 5.1
- light scarification for seedbed preparation or summer logging with no site preparation.
Species choice: - Fd, Pl
Vegetation potential: - low
Reforestation: - manage to maintain Fd component. - as many Fd stems as possible should be left for shade
in order to help reduce excessive drying or heating of upper soil horizons.
- natural Pl and Fd regeneration should be promoted by light scarification or spot screefing.
- fill-planting may be required to meet stocking requirements.
Concerns: - avoid clearcutting as stand establishment would likely be difficult because of high surface soil temperatures and drought.
- these units may represent important early-season range for wildlife, so prescription should be discussed with wildlife personnel.
- site and soil conditions of this unit result in drought hazard for a significant portion of the growing season; leaving a shelterwood overstory can reduce the severity of the drought hazard.
- sites within this unit with shallow and/or coarse- textured soils are vulnerable to nutrient deficiency if forest floors are reduced; site preparation methods that reduce forest floor thickness, such as slashburning or brushblading, must be avoided.
101
Pl - Feathermoss - Cladina
Shepherdia canadensis
Arctostaphylos uva-ursi
Cladina rangiferina
VEGETATION
Tree Layer: 20% cover lodgepole pine
Shrub Layer: 40% cover Shepherdia canadensis (soopolallie) Spiraea betulifolia (birch-leaved spirea) Rosa acicularis (prickly rose)
[Vaccinium myrtilloides (velvet-leaved blueberry)] hybrid white spruce lodgepole pine
Arctostaphylos uva-ursi (kinnikinnick) Cornus canadensis (bunchberry) Linnaea borealis (twinflower) Vaccinium caespitosum (dwarf blueberry) Melampyrum lineare (cow-wheat) Pyrola asarifolia (pink wintergreen) Pyrola chlorantha (green wintergreen) Epilobium angustifolium (fireweed) Galium boreale (northern bedstraw) Goodyera oblongifolia (rattlesnake-plantain) Lycopodium complanatum (ground-cedar)
Salix spp. (willows)
Herb Layer: 50% cover
Moss Layer: 95% cover Pleurozium schreberi (red-stemmed feathermoss) Dicranum polysetum (wavy-leaved moss) Cladina rangiferina (grey reindeer lichen) Cladonia ecmocyna (orange-foot lichen)
SOIL AND SITE
Moisture Regime: 2 (sx) Nutrient Regime: A-B (vp-p)
* Slope Gradient (%): 0 * Slope Position: * Parent Material: (g1acio)fluvial * Soil Texture:
level (usually) or crest
(moderately coarse) - coarse Coarse Fragments (%): 10-65
DISTRIBUTION: uncommon, and restricted to old upper fluvial or glaciofluvial terraces
102
Pl- Feathermoss - Cladina (SBSdw3/03)
INTERPRETATIONS
Site limitations: - sites within this unit with high coarse fragment content (> 70%) will have significantly reduced soil moisture retention and will be extremely difficult to plant; attempt to regenerate naturally by retaining Pl cones and/or leaving Fd seed-trees on site.
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
Site preparation: - light scarification for seedbed preparation or summer logging with no site preparation.
Species choice: - Pl, (Sx)
Vegetation potential: - low
Reforestation: - attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant Pl. - Sx is significantly less productive than Pl on these
sites.
Concerns: - full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (ie., lop
and scatter). - sites within this unit with shallow and/or coarse-
textured soils are vulnerable to nutrient deficiency if forest floors are reduced; site preparation methods that reduce forest floor thickness, such as slashburning or brushblading, must be avoided.
- site and soil conditions of this unit result in drought hazard for a significant portion of the growing season; natural regeneration is generally more adapted to surviving these conditions, especially during establishment.
- comandra blister rust may cause cankers on pine if bastard toad-flax (Geocaulon lividum) occurs nearby.
103
SxwFd - Ricegrass
Shepherdia canadensis
Chimaphila umbellata
Aralia nudicaulis
VEGETATION
Tree Layer: 30% cover lodgepole pine, Douglas-fir, hybrid white spruce
Shrub Layer: 40% cover Rosa acicularis (prickly rose) Spiraea betulifolia (birch-leaved spirea) Amelanchier alnifolia (saskatoon) Shepherdia canadensis (soopolallie) Viburnum edule (highbush-cranberry) [Alnus crispa ssp. sinuata Douglas-fir
(Sitka alder)]
Herb Layer: 30% cover Linnaea borealis (twinflower) Aralia nudicaulis (wild sarsaparilla) Orthilia secunda (one-sided wintergreen) Smilacina racemosa (false Solomon’s-seal) Cornus canadensis (bunchberry) Chimaphila umbellata (prince’s pine) Arnica cordifolia (heart-leaved arnica)
Moss Layer: 80% cover Pleurozium schreberi (red-stemmed feathermoss) Dicranum polysetum (wavy-leaved moss) Ptilium crista-castrensis (knight’s plume) Hylocomium splendens (step moss)
SOIL AND SITE
Moisture Regime: 3 (sm) Nutrient Regime: B-D (p-r) Slope Gradient (%): 5-65
* Slope Position:
* Soil Texture:
mid - upper
usually coarse - moderately coarse
Parent Material: variable
Coarse Fragments (%): 0-70
COMMENTS: similar to SBSdw3/01 but with a less developed shrub layer and generally lacking Rubus parviflorus
DISTRIBUTION: common, and widespread on coarser- textured soils
104
SxwFd - Ricegrass (SBSdw3/04)
INTERPRETATIONS
Site limitations: - sites within this unit with high coarse fragment content (> 70%) will have significantly reduced soil moisture retention and will be extremely difficult to plant; attempt to regenerate naturally by retaining Pl cones and/or leaving Fd seed-trees on site.
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
Site preparation: - light scarification for seedbed preparation or summer logging with no site preparation.
Species choice: - Pl, Fd, (Sx)
Vegetation potential: - low to moderate (trembling aspen, Sitka alder, fireweed)
Reforestation: - manage to maintain Fd component. - attempt to regenerate naturally if potential exists. - if Fd stems are present, conduct a stand evaluation to
assess if a partial cutting system is feasible. - if abundant advance regeneration is present, attempt
to log in a manner that protects this regeneration. - Sx will be significantly less productive than Pl and
Fd on these sites. - fill-planting may be required to meet stocking
requirements if a partial cutting system is used.
Concerns: - full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (ie., lop and scatter)
- site and soil conditions of this unit result in drought hazard for a significant portion of the growing season; leaving a shelterwood overstory can reduce the
severity of the drought hazard. - sites within this unit with shallow and/or coarse-
textured soils are vulnerable to nutrient deficiency if forest floors are reduced; site preparation methods
that reduce forest floor thickness, such as slashburning or brushblading, must be avoided.
- comandra blister rust may cause cankers on pine if bastard toad-flax (Geocaulon lividum) occurs nearby.
105
PlSb - Feathermoss
Vaccinium myrtilloides
Vaccinium caespitosum I
Pleurozium schreberi
VEGETATION
Tree Layer: 30% cover lodgepole pine, black spruce
Shrub Layer: 30% cover Rosa acicularis (prickly rose) Shepherdia canadensis (soopolallie) Vaccinium myrtilloides (velvet-leaved blueberry) Lonicera involucrata (black twinberry) Spiraea betulifolia (birch-leaved spirea) Amelanchier alnifolia (saskatoon) black spruce
Herb Layer: 40% cover Cornus canadensis (bunchberry) Linnaea borealis (twinflower) Vaccinium caespitosum (dwarf blueberry) Fragaria virginiana (wild strawberry) Oryzopsis asperifolia (rough-leaved ricegrass) Epilobium angustifolium (fireweed) Aster ciliolatus (fringed aster)
Moss Layer: 95% cover Pleurozium schreberi (red-stemmed feathermoss) Dicranum polysetum (wavy-leaved moss)
SOIL AND SITE
Moisture Regime: 3-5 (sm-shg)
Nutrient Regime: A-B (vp-p) * Slope Gradient (%): 0-9
Slope Position: variable Parent Material: (glacio)fluvial, morainal or
Soil Texture: coarse - fine Coarse Fragments (%): 0-88
lacustrine
* Root-restricting Layer: often present within 25 cm of humus/mineral soil interface
COMMENTS: these sites appear to be nutrient-poor because of restricted rooting, saturated soils in spring, and droughty conditions in late summer
DISTRIBUTION: common on level terrain
106
PlSb - Feathermoss (SBSdw3/05)
INTERPRETATIONS
Site limitations: - soils are saturated in the spring, but may experience drought in summer, both resulting in poor root development; the poor productivity resulting from these limitations should dictate a limited intensive silvicultural investment.
- compact soil layers and/or low aeration porosity associated with fine-textured soils will reduce rooting depth and decrease productivity over a rotation; regenerate naturally whenever possible.
- sites within this unit with medium to fine-textured lacustrine soils often have poor soil structure, leading to poor root growth; plant stock that will achieve better lateral root development (eg., Cu-treated), prescribe natural regeneration, or protect advance regeneration.
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
Site preparation: - see Section 5.2
Species choice: - Pl , (SX, Sb)
Vegetation potential: - low
Reforestation: - attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant Pl. - Sx and Sb will generally be significantly less
productive than Pl on these sites.
Concerns: - sites within this unit with shallow and/or coarse- textured soils are vulnerable to nutrient deficiency if forest floors are reduced; site preparation methods that reduce forest floor thickness, such as slashburning or brushblading, must be avoided.
- sites within this unit with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations or dry soil
conditions. - comandra blister rust may cause cankers on pine if
bastard toad-flax (Geocaulon lividum) occurs nearby.
107
Sxw - Pink spirea - Prickly rose
Spiraea douglasii
ssp. menziesii
Petasites frigidus
var. palmatus
Lathyrus ochroleucus
VEGETATION
Tree Layer: 45% cover lodgepole pine, trembling aspen, [black spruce]
Shrub Layer: 60% cover Spiraea douglasii ssp. menziesii (pink spirea) Rosa acicularis (prickly rose) Viburnum edule (highbush-cranberry) Lonicera involucrata (black twinberry) Shepherdia canadensis (soopolallie) Amelanchier alnifolia (saskatoon) hybrid white spruce
Herb Layer: 35% cover Cornus canadensis (bunchberry) Rubus pubescens (trailing raspberry) Linnaea borealis (twinflower) Petasites frigidus var. palmatus (palmate coltsfoot) Lathyrus ochroleucus (creamy peavine) Calamagrostis canadensis (bluejoint) Fragaria virginiana (wild strawberry) Vaccinium caespitosum (dwarf blueberry) Aster ciliolatus (fringed aster) Epilobium angustifolium (fireweed) Pyrola asarifolia (rosy wintergreen)
Moss Layer 95% cover Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) Peltigera aphthosa (freckle lichen)
SOIL AND SITE
Moisture Regime: 4-5 (m-shg) Nutrient Regime: B-D (p-r)
Slope Position: level * Slope Gradient (%):
* Parent Material: lacustrine * Soil Texture: * Coarse Fragments (%):
0-10, usually < 5
moderately fine - fine generally 0
DISTRIBUTION: uncommon; often agricultural land
108
Sxw - Pink spirea - Prickly rose (SBSdw3/06)
INTERPRETATIONS
Site limitations: - sites within this unit with medium- to fine-textured lacustrine soils often have poor soil structure, leading to poor root growth; plant stock that will achieve better lateral root development (eg., Cu-treated), prescribe natural regeneration, or protect advance regeneration.
Silviculture systems:
Site preparation:
- see Section 5.1
- see Section 5.2
Species choice: - [Pl], SX, Fd, [Bl]
Vegetation potential: - moderate (trembling aspen, black twinberry, fireweed)
Reforestation: - a combination of poorly structured soils and frost make these sites difficult to regenerate, so if good quality advance regeneration is present it should be preserved during harvesting.
- supplement advance regeneration by planting sturdy stock in groups on available raised microsites.
- help maintain stand diversity on sites to be planted with Pl by mapping aspen patches prior to harvest and planting these areas to spruce.
- young Bl regeneration (< 3 m tall) may be susceptible to heavy browsing by moose.
Concerns: - sites within this unit with fine-textured soils are very vulnerable to compaction under wet conditions; restrict traffic to winter operations.
- site conditions may lead to frost damage of Sx and Fd regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) is advised.
- sites within this unit with silty soils are susceptible to frost-heaving; bareroot stock will likely resist frost-heaving better than plug stock.
- if a root-restricting layer is present within 30 cm of surface then sites will have a high blowdown risk.
- comandra blister rust may cause cankers on pine if bastard toad-flax (Geocaulon lividum) occurs nearby.
- mountain pine beetle may cause mortality in large- diameter lodgepole pine stands of age class > 7.
109
Sxw - Twinberry
Lonicera involucrata
Petasites frigidus
var. palmatus
VEGETATION
Tree Layer: 40% cover hybrid white spruce, trembling aspen
Lonicera involucrata (black twinberry) Viburnum edule (highbush-cranberry) Rosa acicularis (prickly rose) Ribes lacustre (black gooseberry) Cornus stolonifera (red-osier dogwood) hybrid white spruce
Herb Layer: 60% cover
Shrub Layer: 30% cover
Cornus canadensis (bunchberry) Petasites frigidus var. palmatus (palmate coltsfoot) Rubus pubescens (trailing raspberry) Linnaea borealis (twinflower) Smilacina racemosa (false Solomon's seal) Aster ciliolatus (fringed aster) Mitella nuda (common mitrewort)
Moss Layer 95% cover Hylocomium splendens (step moss) Ptilium crista-castrensis (knight's plume) Pleurozium schreberi (red-stemmed feathermoss) Mnium spp. (leafy mosses)
SOIL AND SITE
Moisture Regime: 5 (shg) Nutrient Regime: C-D (m-r)
* Aspect: flat or northerly * Slope Gradient (%): 0-15, usually < 8
Slope Position: variable Parent Material: lacustrine or occasionally
Soil Texture: variable (not coarse) Coarse Fragments (%): 0-36
morainal
DISTRIBUTION: uncommon; often agricultural land or as small bands on lower slope positions
Hylocomium splendens
110
Sxw - Twinberry (SBSdw3/07)
INTERPRETATIONS
Site limitations: - sites within this unit with medium to fine textured lacustrine soils often have poor soil structure, leading to poor root growth; plant stock that will achieve better lateral root development (eg., Cu-treated), prescribe natural regeneration, or protect advance regeneration.
Silviculture systems:
Site preparation:
- see Section 5.1
- see Section 5.2
Species choice: - Pl, SX, Fd, [Bl]
Vegetation potential: - moderate (trembling aspen, black twinberry, fireweed)
Reforestation: - if vigorous advanced Fd or Sx regeneration is present,
- plant sturdy stock as soon after harvesting as
- plant Fd only on coarse-textured sites. - young Bl regeneration (< 3 m tall) may be susceptible
to heavy browsing by moose. - help maintain stand diversity on sites to be planted
with Pl by mapping aspen patches prior to harvest and planting these areas to spruce.
- fill-planting will likely be required if a partial cutting silviculture system is used.
it should be preserved when feasible.
possible.
Concerns: - site conditions may lead to frost damage of Fd and Sx regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) is advised.
- sites within this unit with silty soils are susceptible to frost-heaving; bareroot stock will likely resist frost-heaving better than plug stock.
- sites within this unit with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations or dry soil conditions.
- spruce weevil constitutes a moderate hazard in southeastern portion of subzone; consider modifying brush treatments in localized areas with > 5% current attack.
- tomentosus root rot may cause moderate to severe problems in mature spruce-dominated stands.
111
Sxw - Oakfern
Lonicera involucrata
Gymnocarpium
dryopteris
Pleurozium schreberi
VEGETATION
Tree Layer: 45% cover hybrid white spruce, Douglas-fir, lodgepole pine
Shrub Layer: 40% cover Viburnum edule (highbush-cranberry) Lonicera involucrata (black twinberry) Rosa acicularis (prickly rose) Spiraea betulifolia (birch-leaved spirea) subalpine fir hybrid white spruce
Herb Layer: 75% cover Gymnocarpium dryopteris (oak fern) Cornus canadensis (bunchberry) Aralia nudicaulis (wild sarsaparilla) Mitella nuda (common mitrewort) Rubus pubescens (trailing raspberry) Orthilia secunda (one-sided wintergreen)
Moss Layer: 75% cover Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) Rhytidiadelphus triquetrus (electrified cat’s-tail moss) Mnium spp. (leafy mosses)
SOIL AND SITE
Moisture Regime: 5-6 (shg-hg) Nutrient Regime: C-E (m-vr)
* Slope Gradient (%): * Slope Position:
2-90 (rarely 0) lower - toe or mid if northerly aspect
lacustrine
moderately coarse or medium
Parent Material: fluvial; rarely morainal or
Soil Texture: coarse; occasionally
Coarse Fragments (%): 0-70
COMMENTS: these sites are on warmer soils than the SBSdw3/06, which is reflected in better forest productivity
DISTRIBUTION: uncommon, and generally restricted to lower slopes
112
Sxw - Oakfern (SBSdw3/08)
INTERPRETATIONS
Site limitations: - sites within this unit with medium- to fine-textured lacustrine soils often have poor soil structure, leading to poor root growth; plant stock that will achieve better lateral root development (eg., Cu-treated), prescribe natural regeneration, or protect advance regeneration.
Silviculture system:
Site preparation:
- see Section 5.1
- see Section 5.2
Species choice: - Pl, SX, Fd, [Bl]
Vegetation potential: - moderate (trembling aspen, black twinberry, prickly rose, fireweed)
Reforestation: - if vigorous advanced Fd or Sx regeneration is present, it should be preserved when feasible.
- plant sturdy stock as soon after harvesting as possible.
- Fd should only be planted on coarse-textured sites with low frost hazard.
- young Bl regeneration (< 3 m tall) may be susceptible to heavy browsing by moose.
- help maintain stand diversity on sites to be planted with Pl by mapping aspen patches prior to harvest and planting these areas to spruce.
- fill-planting will likely be required if a partial cutting silviculture system is used.
Concerns: - site conditions may lead to frost damage of Fd regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) is advised.
- sites within this unit with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations or dry soil conditions.
- spruce weevil constitutes a moderate hazard in southeastern portion of subzone; consider modifying brush treatments in localized areas with > 5% current attack.
- tomentosus root rot may cause moderate to severe problems in mature spruce-dominated stands.
113
Sxw - Horsetail - Glowmoss
Lonicera involucrata
Equisetum arvense
Rubus pubescens
VEGETATION
Tree Layer: 30% cover hybrid white spruce
Shrub Layer: 20% cover Lonicera involucrata (black twinberry) Rosa acicularis (prickly rose) Ribes lacustre (black gooseberry) Vaccinium membranaceum (black huckleberry) hybrid white spruce
Herb Layer: 80% cover Equisetum arvense (common horsetail) Equisetum sylvaticum (wood horsetail) Rubus pubescens (trailing raspberry) Linnaea borealis (twinflower) Mitella nuda (common mitrewort) Galium triflorum (sweet-scented bedstraw) Cornus canadensis (bunchberry) Gymnocarpium dryopteris (oak fern)
Moss Layer: 65% cover Pleurozium schreberi (red-stemmed feathermoss) Hylocomium splendens (step moss) Ptilium crista-castrensis (knight’s plume) Mnium spp. (leafy mosses)
SOIL AND SITE
Moisture Regime: 6 (hg) Nutrient Regime : B-E (p-vr)
* Slope Gradient (%): * Slope Position: * Parent Material:
Soil Texture:
Coarse Fragments (%):
0-4, usually 0 toe, depression (or level) organic or fluvial medium - coarse if mineral soil 0-27 (0 if organic)
COMMENTS: sites within this unit with deeper fluctuating water tables have upland humus forms and will be drier during the summer
DISTRIBUTION: common, but restricted to narrow bands along creeks and rivers or edges of wetlands
114
Sxw - Horsetail - Glowmoss (SBSdw3/09)
INTERPRETATIONS
Site limitations: - very difficult sites to manage; serious consideration should be given to managing these sites as wildlife corridors.
- sites within this unit with saturated soils are poorly aerated, which slows root development; plant seedlings on naturally or artificially raised microsites.
Silviculture system:
Site preparation:
- see Section 5.1
- see Section 5.2 - creating an excessive number of mounds (eg.,
>300/ha) should be avoided, especially on sites within this unit with a water table < 30 cm from the surface.
Species choice:
Vegetation potential:
Reforestation:
- Pl, Sx, [Bl]
- high (black twinberry, fireweed, bluejoint)
- advanced regeneration should be preserved. - supplement advance regeneration by planting sturdy
stock in groups, using available raised microsites. - young Bl regeneration (< 3 m tall) may be susceptible
to heavy browsing by moose.
Concerns : - site conditions may lead to frost damage of Sx and Bl regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) is advised
- these units may represent important wildlife habitat; discuss prescription with wildlife personnel.
- water table will likely rise above the ground surface in the spring, causing seedling mortality.
- this unit is critical to the control of runoff streamflow. - sites with thick organic horizons (> 10 cm) will have
an extreme windthrow hazard; block layouts must have windfirm boundaries, or a wide buffer of standing timber must be left around such sites.
- spruce weevil constitutes a moderate hazard in southeastern portion of subzone; consider modifying brush treatments in localized areas with > 5% current attack.
- tomentosus root rot may cause moderate to severe problems in mature spruce-dominated stands.
- Warren’s root collar weevil can cause mortality in young stands, especially where duff layers are thick.
115
Ledum groenlandicum
Equisetum arvense
Sb - Soft-leaved sedge - Sphagnum
VEGETATION
Tree Layer: 10% cover black spruce, [tamarack]
Shrub Layer: 30% cover Ledum groenlandicum (Labrador tea) Lonicera involucrata (black twinberry) Ribes hudsonianum (northern black currant) black spruce
Herb Layer: 80% cover Equisetum arvense (common horsetail) Potentilla palustris (marsh cinquefoil) Mitella nuda (common mitrewort) Cornus canadensis (bunchberry)
Moss Layer: 65% cover Pleurozium schreberi (red-stemmed feathermoss) Sphagnum capillaceum (common red sphagnum) Mnium spp. (leafy mosses) Ptilium crista-castrensis (knight's plume) Hylocomium splendens (step moss)
SOIL AND SITE
Moisture Regime: 7 (shd) Nutrient Regime: A-D (vp-r)
* Slope Gradient (%): 0 * Slope Position: * Parent Material: organic
depression or level
Soil Texture: not applicable Coarse Fragments (%): 0
DISTRIBUTION: common, but usually small in size
Potentilla palustris
116
Sb - Soft-leaved sedge - Sphagnum (SBSdw3/10)
INTERPRETATIONS
Site limitations: - site and soil conditions of this unit result in marginal forest productivity; serious consideration should be given to excluding logging from this unit.
Silviculture system: - avoid logging
117
4.4
Location The SBSmc2 occurs in the western portion of the guide area, generally at elevations between 900 and 1200 m. Over most of the guide area it is bordered at lower elevations by the SBSdk and at its upper limits by the ESSFmv1 (Figure 1). In the southwestern portion of the guide area it occurs as a thin band on warm aspects above the SBSmc3 and below the ESSFmv1.
Elevation range 850 - 1350 m
Climate The SBSmc2 has the wettest and snowiest climate of the SBS biogeoclimatic units in the guide area (Table 8). Not only does it snow more, but the snow- pack also comes earlier and lasts longer than all the other units except the SBSmc3 and ESSFmv1.
Soils, geology, and landforms Bedrock geology in this subzone is diverse, and includes Palaeozoic sedimentary rocks, Palaeozoic to Mesozoic intrusive rocks (diorite), and Tertiary volcanics (basalt, andesite, and dacite). Parent materials are dominantly morainal, with gravelly loam and clay loam textures. The associated soils are Brunisolic Gray Luvisols. Dystric Brunisols and Humo- Ferric Podzols have formed on coarser colluvial and glaciofluvial materials (gravelly sandy loam and sand).
Distinguishing the SBSmc2 from adjoining biogeoclimatic units SBSdk has: • no subalpine fir in the canopy; • more prickly rose but less black huckleberry in the shrub layer; • purple peavine but almost no five-leaved bramble in the herb layer; and • devil's club and oakfern commonly occuring on moister sites. SBSdw3 has: • Douglas-fir but less subalpine fir in the canopy; • saskatoon but less black huckleberry in the shrub layer; and • false sarsaparilla but less five-leaved bramble in the herb layer. SBSmc3 has: • more palmate coltsfoot but less five-leaved bramble; and • more fringed aster but less devil's club and oak fern on wetter sites. SBSwk3 has: • devil's club but less prickly rose in the shrub layer on mesic sites; and • oakfern abundant on mesic sites. ESSFmv1 has: • white-flowered rhododendron but no prickly rose on mesic and wetter sites;
• no devil's club and little to no oakfern on wetter sites.
Babine Moist Cold Sub-Boreal Spruce 11
and
11 Formerly SBSe1
119
Forests Climax forests are dominated by hybrid white spruce and subalpine fir. Lodgepole pine is common on all sites but tends to dominate on drier sites. Black spruce occurs in wetlands and also on upland sites on poor soils in combination with lodgepole pine. Black cottonwood occurs along streams and rivers and is often associated with hybrid white spruce. Forest productivity is moderate but is limited by the relatively short growing season.
Wildlife Moist sites provide habitat for moose. Open forested wetlands provide important spring forage for black bear and grizzly bear. Coniferous sub-boreal forests are used by marten, red squirrel, and spruce grouse.
120
Soil Nutrient Regime
Very Poor Poor Medium Rich Very Rich
A B C D E
Very Xeric 0
Xeric 1
Subxeric 2
Submesic 3
Mesic 4
Subhygric 5
Hygric 6
Subhydric 7
01 Sxw - Huckleberry
02 Pl - Huckleberry - Cladonia
03 SbPl - Feathermoss
04 Sxw - Huckleberry - Dwarf
05 Sxw - Twinberry - Coltsfoot
06 Sxw - Oak fern
07 Sxw - Scrub birch -
Feathermoss
08 Sxw - Twinberry - Oak fern 09 Sxw - Devil's club
11 Sxw - Horsetail - Glow moss
12 SbSxw - Scrub birch - Sedge
blueberry 10 Sxw - Horsetail
FIGURE 15. Edatopic grid displaying site units in the SBSmc2 variant.
121
Site Units 02 03 04 01 05 06 07 08 09 10 11 12
Trees Pinus cotorta
Picea glauca x engelmannii
Populus tremuloides
Picea mariana
Shrubs Vaccinium membranaceum
Alnus crispa ssp. sinuata
Rubus parvivlorus
Ribes lacustre
Lonicera involucrata
Oplopanax horridus
Alnus tenuifolia
Salix spp. (glauca, barclayi)
Betula glandulosa
Ledum groenlandicum
Herbs and Dwarf Shrubs Arctostaphylos uva-ursi
Vaccinium caespitosum
Rubus pedatus
Gymnocarpium dryopteris
Equisitum sylvaticum
Gaultheria hispidula
Equisetum arvense
Rubus pubescens
FIGURE 16 SBSmc2 vegetation table.
lodgepole pine
hybrid white spruce
trembling aspen
black spruce
black huckleberry
Sitka alder
thimb1eberry
black gooseberry
black twinberry
devil's club
mountain alder
willows
scrub birch
Labrador tea
kinnikinnick
dwarf blueberry
five-leaved bramble
trailing raspberry
oak fern
wood horsetail
creeping-snowberry
common horsetail
Prominence class:
Site Units 02 03 04 01 05 06 07 08 09 10 11 12
Herbs and Dwarf Shrubs (continued)
Carex aquatilis
Rubus chamaemorus
Mosses and Lichens Cladonia spp.
Cladina spp.
Pleurozium schreberi
Mnium spp.
Aulacomnium palustre
Sphagnum spp.
Tomenthypnum nitens
FIGURE 16 SBSmc2 vegetation table (continued)
water sedge
cloudberry
cladonia lichens
cladina lichens
red-stemmed feathermoss
leafy mosses
glow moss
sphagnums
golden fuzzy fen moss
Prominence class:
1a Black spruce always present; poor tree productivity; Ledum groenlandicum (p. 40) 12 or Betula glandulosa (p. 39) abundant.
2a Canopy of stunted black spruce; on wet organic soils; moss layer dominated by Sphagnum spp. (p. 312).
SBSmc2/12
Canopy of lodgepole pine and black spruce; on mineral soils; moss layer dominated by feathermosses.
SBSmc2/03
Black spruce rare; variable tree productivity; Ledum groenlandicum and Betula glandulosa generally absent.
3a
2b
1 b
Sites with poor tree productivity; soil conditions either very dry or wet and nutrient poor; Cladina spp. (p. 334) or Aulacomnium palustre (p. 311) abundant (> 1% cover).
4a Canopy almost exclusively lodgepole pine; on well-drained, coarse-textured soils or shallow soils over bedrock; moss layer dominated by lichens.
SBSmc2/02
Mixed canopy of white spruce and lodgepole pine; on imperfectly drained soils; moss layer dominated by mosses.
4b
SBSmc2/07
Sites with moderate or better tree productivity; soil conditions not as in 3a; Cladina spp. and Aulacomnium palustre low cover (< 1%), or absent.
5a
3b
Canopy dominated by white spruce; water table generally present within 50 cm of soil surface; Oplopanax horridus (p. 36) or Equisetum spp. (p. 280) abundant (> 10% cover).
6a Generally found in sloping topography on lower to toe slopes; Oplopanax horridus abundant.
SBSmc2/09
Found on flat or depressional topography adjacent to water courses or wetlands; Oplopanax horridus rare.
6b
SBSmc2/10,11 13
12 Page numbers refer to the publication Plants of Northern British Columbia (MacKinnon et al. 1992).
13 Refer to descriptions for differentiation.
124
5b Canopy dominated by white spruce or lodgepole pine; water table generally absent; Oplopanax horridus and Equisetum spp. low cover (< 10%) or absent.
7a Canopy generally dominated by white spruce; evidence of periodic seepage (mottles) generally present; Lonicera involucrata (p. 48) and/or Rubus parviflorus (p. 36) abundant (> 5% cover).
8a More common on warm (southerly) aspects; shrub layer dominated by Rubus parviflorus; Gymnocarpium dryopteris (p. 293) absent.
SBSmc2/05
8b Found on all aspects; shrub layer generally not dominated by Rubus parviflorus; Gymnocarpium dryopteris present and abundant.
9a Slope position lower or depression; often in areas of cold air drainage; Lonicera involucrata abundant, Oplopanax horridus absent.
SBSmc2/08
Slope position variable; generally not in areas of cold air drainage; Lonicera involucrata not abundant, Oplopanax horridus generally present.
SBSmc2/06
Canopy often dominated by lodgepole pine; evidence of periodic seepage (mottles) generally lacking; Lonicera involucrata and Rubus parviflorus low cover (< 5%) or absent.
10a Generally mesic to subhygric moisture regime; Rubus pubescens (p. 91) or Petasites frigidus var. palmatus (p. 114) present.
SBSmc2/04
10b Generally mesic to submesic moisture regime; Rubus pubescens and Petasites frigidus var. palmatus generally low cover or absent.
SBSmc2/01
9b
7b
125
Sxw - Huckleberry
Vaccinium
membranaceum
Rubus pedatus
VEGETATION
Tree Layer: 55% cover lodgepole pine, subalpine fir, hybrid white spruce
Shrub Layer: 50% cover Vaccinium membranaceum (black huckleberry) [Rosa acicularis (prickly rose)] [Lonicera involucrata (black twinberry)] subalpine fir
Herb Layer: 40% cover Cornus canadensis (bunchberry) Rubus pedatus (five-leaved bramble) Linnaea borealis (twinflower) Arnica cordifolia (heart-leaved arnica)
Moas Layer: 75% cover Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) [Hylocomium splendens (step moss)]
SOIL AND SITE
Moisture Regime: 3-4 (sm-m) Nutrient Regime: B-D (p-r)
Slope Position: all except crest Parent Material: morainal or glaciofluvial Soil Texture: variable Coarse Fragments (%): not available
Slope Gradient (%): 0-30
DISTRIBUTION: common, widespread, and often large
Pleurozium schreberi
126
Sxw - Huckleberry (SBSmc2/01)
INTERPRETATIONS
Site limitations: - sites within this unit with medium- to fine-textured lacustrine soils often have poor soil structure, leading to poor root growth; plant stock that will achieve better lateral root development (eg., Cu-treated), prescribe natural regeneration, or protect advance regeneration.
Silviculture system:
Site preparation:
- see Section 5.1
- see Section 5.2
Species choice: - Pl, SX, Bl
Vegetation potential:
Reforestation:
- moderate (trembling aspen, fireweed, thimbleberry)
- attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant a mix of
- prefer Pl over Sx at drier end of this unit. - young Bl regeneration (< 3 m tall) may be susceptible
to heavy browsing by moose. - try to preserve advance regeneration if it is abundant
and likely to release and form an acceptable stand. - advance Bl regeneration should only be accepted if it
is likely to reach management objective before it is 150 years old.
- help maintain stand diversity on sites to be planted with Pl by mapping aspen patches prior to harvest and planting these areas to spruce.
Pl and Sx.
Concerns: - full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (ie., lop and scatter)
- site conditions may lead to frost damage of regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a fist-resistant species (eg., Pl) is advised.
127
Pl - Huckleberry - Cladonia
Shepherdia canadensis
Arctostaphylos
uva-ursi
VEGETATION
Tree Layer: 35% cover lodgepole pine
Vaccinium membranaceum (black huckleberry) Shepherdia canadensis (soopolallie) [lodgepole pine] [subalpine fir]
Arctostaphylos uva-ursi (kinnikinnick) Linnaea borealis (twinflower) Cornus canadensis (bunchberry) Vaccinium caespitosum (dwarf blueberry)
Shrub Layer: 45% cover
Herb Layer: 25% cover
Moss Layer: 75% cover Cladonia spp. (cladonia lichens) Cladina spp. (cladina lichens) Pleurozium schreberi (red-stemmed feathermoss)
SOIL AND SITE
Moisture Regime: 1-2 (x-sx) Nutrient Regime: A-C (vp-m) Slope Gradient (%): 0-30
* Slope Position: level, crest, and upper
morainal over bedrock Parent Material: (glacio)fluvial; colluvial or
* Soil Texture: generally coarse Coarse Fragments (%): not available
DISTRIBUTION: uncommon, except in areas of large coarse-textured fluvial or glaciofluvial terraces
Cladonia spp.
128
Pl - Huckleberry - Cladonia (SBSmc2/02)
INTERPRETATIONS
Site limitations: - site and soil conditions of this unit result in marginal forest productivity; serious consideration should be given to excluding logging from this unit.
- sites within this unit with high coarse fragment content (> 70%) will have significantly reduced soil moisture retention and will be extremely difficult to plant; attempt to regenerate naturally by retaining Pl cones.
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
- no site preparation Site preparation:
Species choice: - Pl
Vegetation potential: - low
Reforestation: - attempt to regenerate naturally if potential exists. - i f natural regeneration is not feasible, plant Pl
without site preparation.
Concerns: - full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (ie., lop and scatter)
- site and soil conditions of this unit result in drought hazard for a significant portion of the growing season; natural regeneration is generally more adapted to surviving these conditions, especially during establishment.
- sites within this unit are vulnerable to nutrient deficiency if forest floors are reduced; site preparation methods that reduce forest floor thickness, such as slashburning or brushblading, must be avoided.
129
SbPl - Feathermoss
Ledum groenlandicum
Gaultheria hispidula
VEGETATION
Tree Layer: 45% cover lodgepole pine, black spruce, hybrid white spruce
Shrub Layer: 30% cover Ledum groenlandicum (Labrador tea) Vaccinium membranaceum (black huckleberry) black spruce hybrid white spruce subalpine fir
Herb Layer: 60% cover Cornua canadensis (bunchberry) Vaccinium caespitosum (dwarf blueberry) Gaultheria hispidula (creeping-snowberry) Petasites frigidusus var. palmatus (palmate coltsfoot) Lycopodium annotinum (stiff clubmoss) Empetrum nigrum (crowberry)
Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) Peltigera spp. (peltigera lichens)
Moss Layer: 95% cover
SOIL AND SITE
Moisture Regime: 3-5 (sm-shg) Nutrient Regime: A-B (vp-p)
* Slope Gradient (%): 0-5 * Slope Position: lower - level
Parent Material: morainal; occasional fluvial veneers
Soil Texture: medium - moderately coarse Coarse Fragments (%): not available
DISTRIBUTION: uncommon; occurs mainly on cold northerly aspects
Pleurozium schreberi
130
SbPl - Feathermoss (SBSmc2/03)
INTERPRETATIONS
Site limitations: - soils are saturated in the spring, but may experience drought in summer, both resulting in poor root development; the poor productivity resulting from these limitations should dictate a limited intensive silvicultural investment.
- compact soil layers and/or low aeration porosity associated with fine-textured soils will reduce rooting depth and decrease productivity over a rotation; regenerate naturally whenever possible.
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
Site preparation: - see Section 5.2
Species choice: - Pl, (Sx, Sb, Bl)
Vegetation potential: - low
Reforestation: - attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant Pl. - Sx and Sb are not as productive on these sites as Pl.
- full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (ie., lop and scatter).
- site conditions may lead to frost damage of regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) is advised.
Concerns:
131
Lonicera involucrata
Vaccinium
membranaceum
Rubus pubescens
Sxw - Huckleberry - Dwarf blueberry
VEGETATION
Tree Layer: 35% cover lodgepole pine, hybrid white spruce
Shrub Layer: 15% cover Lonicera involucrata (black twinberry) Vaccinium membranaceum (black huckleberry) Rosa acicularis (prickly rose) Spiraea betulifolia (birch-leaved spirea) Alnus crispa ssp. sinuata (Sitka alder) subalpine fir
Herb Layer: 25% cover Cornus canadensis (bunchberry) Linnaea borealis (twinflower) Mitella nuda (common mitrewort) Arnica cordifolia (heart-leaved arnica) Rubus pubescens (trailing raspberry) Petasites frigidus var. palmatus (palmate coltsfoot) Epilobium angustifolium (fireweed) Listera cordata (heart-leaved twayblade) Rubus pedatus (five-leaved bramble) Orthilia secunda (one-sided wintergreen) Calamagrostis rubescens (pinegrass) Vaccinium caespitosum (dwarf blueberry) Osmorhiza chilensis (mountain sweet-cicely)
Moss Layer: 85% cover Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) Hylocomium splendens (step moss) Peltigera aphthosa (freckle lichen)
SOIL AND SITE
Moisture Regime: 4-5 (m-shg) Nutrient Regime: C-D (m-r)
* Slope Gradient (%): 0-25 * Slope Position: mid to lower or level
Parent Material generally morainal Soil Texture: variable, but generally
Coarse Fragments (%): 0-95 medium to coarse
DISTRIBUTION: common, and widespread in the southern portion of guide area
132
Sxw - Huckleberry - Dwarf blueberry (SBSmc2/04)
INTERPRETATIONS
Site limitations: - sites within this unit with colluvial soils may be difficult to plant; attempt to regenerate naturally or make use of advance regeneration.
- sites within this unit with high coarse fragment content (> 70%) will have significantly reduced soil moisture retention and will be extremely difficult to plant; attempt to regenerate naturally by retaining Pl cones.
Silviculture system:
Site preparation:
- see Section 5.1
- see Section 5.2
Species choice: - SX, Pl, Bl
Vegetation potential:
Reforestation:
- moderate (black twinberry, thimbleberry, fireweed)
- try to preserve advance regeneration if it is abundant and likely to release and form an acceptable stand.
- advance Bl regeneration should only be accepted if it is likely to reach management objective before it is 150 years old.
- fill-planting will likely be required if stand is partially cut.
- young Bl regeneration (< 3 m tall) may be susceptible to heavy browsing by moose.
- if advance regeneration is not acceptable, plant sturdy stock as soon after harvesting as possible.
Concerns: - sites within this unit with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations or dry soil conditions.
133
Rubus parviflorus
Rubus pubescens
Pleurozium schreberi
Sxw - Twinberry - Coltsfoot
VEGETATION
Tree Layer: 55% cover hybrid white spruce, trembling aspen, lodgepole pine, [subalpine fir]
Shrub Layer: 60% cover Rubus parviflorus (thimbleberry) Viburnum edule (highbush-cranberry) Lonicera involucrata (black twinberry) Ribes lacustre (black gooseberry) Rosa acicularis (prickly rose) Cornus stolonifera (red-osier dogwood) [hybrid white spruce1 [subalpine fir]
Herb Layer: 60% cover Rubus pubescens (trailing raspberry) Cornus canadensis (bunchberry) Epilobium angustifolium (fireweed) Arnica cordifolia (heart-leaved arnica) Osmorhiza chilensis (mountain sweet-cicely) [Smilacina racemosa (false Solomon’s-seal)] [Thalictrum occidentale (western meadowrue)]
Moss Layer: 55% cover Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) Hylocomium splendens (step moss)
SOIL AND SITE
Moisture Regime: 4-5 (m-shg) Nutrient Regime : C-D (m-r) Slope Gradient (%): 2-49
* Slope Position: mid, lower, and toe Parent Material: morainal, fluvial, and
colluvial Soil Texture: variable Coarse Fragments (%): not available
DISTRIBUTION: common, except in southern portion of Prince George Forest Region
134
Sxw - Twinberry - Coltsfoot (SBSmc2/05)
INTERPRETATIONS
Site limitations: - sites within this unit with colluvial soils may be difficult to plant; attempt to regenerate naturally or make use of advance regeneration.
Silviculture system:
Site preparation:
- see Section 5.1
- see Section 5.2
Species choice: - SX, Pl, Bl
Vegetation potential: - moderate to high (black twinberry, thimbleberry, fireweed)
Reforestation: - try to preserve advance regeneration if it is abundant and likely to release and form an acceptable stand.
- advance Bl regeneration should only be accepted if it is likely to reach management objective before it is 150 years old.
- young Bl regeneration (< 3 m tall) may be susceptible to heavy browsing by moose.
- fill-planting will likely be required if a partial cutting silviculture system is used.
- if advance regeneration is unacceptable, plant sturdy stock as soon after harvesting as possible.
- planting of Sx in obvious frost pockets should be avoided unless risk can be reduced by providing cover.
- help maintain stand diversity on sites to be planted with Pl by mapping aspen patches prior to harvest and planting these areas to spruce.
Concerns: - sites within this unit with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations or dry soil conditions.
- black army cutworm can cause severe defoliation on south-facing slopes that have been slashburned.
135
Sxw - Oakfern
Rubus parviflorus
Gymnocarpium
dryopteris
VEGETATION
Tree Layer: 50% cover hybrid white spruce, subalpine fir, [lodgepole pine]
Shrub Layer: 50% cover Ribes lacustre (black gooseberry) Rubus parviflorus (thimbleberry) Vaccinium membranaceum (black huckleberry) Oplopanax horridus (devil’s club) subalpine fir
Herb Layer: 65% cover Gymnocarpium dryopteris (oak fern) Cornus canadensis (bunchberry) Rubus pedatus (five-leaved bramble) Tiarella trifoliata (three-leaved foamflower) [Streptopus amplexifolius (clasping twistedstalk)]
Moss Layer: 70% cover Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) Barbilophozia lycopodioides (common leafy liverwort) Hylocomium splendens (step moss) [Brachythecium spp. (brachythecium mosses)]
SOIL AND SITE
Moisture Regime: 4-5 (m-shg) Nutrient Regime: D-E (r-vr)
Slope Position: upper - toe
Parent Material: morainal, lacustrine or colluvial
Soil Texture: variable Coarse Fragments (%): not available
Slope Gradient (%): 3-60
* Aspect: generally northerly
DISTRIBUTION: common, especially on northerly aspects
Tiarella trifoliata
136
Sxw - Oakfern (SBSmc2/06)
INTERPRETATIONS
Site limitations: - sites within this unit with medium- to fine-textured lacustrine soils often have poor soil structure, leading to poor root growth; plant stock that will achieve better lateral root development (e.g., Cu-treated), prescribe natural regeneration, or protect advance regeneration.
- sites within this unit with colluvial soils may be difficult to plant; attempt to regenerate naturally or make use of advance regeneration.
Silviculture system:
Site preparation:
- see Section 5.1
- see Section 5.2
Species choice: - SX, Pl, Bl
Vegetation potential:
Reforestation:
- moderate (black twinberry, thimbleberry, fireweed)
- try to preserve advance regeneration if it is abundant and likely to release and form an acceptable stand.
- advance Bl regeneration should only be accepted if it is likely to reach management objective before it is 150 years old.
- young Bl regeneration (< 3 m tall) may be susceptible to heavy browsing by moose.
- fill-planting will likely be required if a partial cutting silviculture system is used.
- if advance regeneration is unacceptable, plant sturdy stock as soon after harvesting as possible.
- planting of Sx in obvious frost pockets should be avoided unless risk can be reduced by providing cover.
Concerns: - sites within this unit with silty soils are susceptible to frost-heaving; bareroot stock will likely resist frost-heaving better than plug stock.
- sites within this unit with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations or dry soil conditions.
- Warren’s root collar weevil can cause mortality in young stands, especially where duff layers are thick.
137
Lonicera involucrata
Betula glandulosa
Sxw - Scrub birch - Feathermoss
VEGETATION
Tree Layer: 50% cover lodgepole pine, hybrid white spruce, [trembling aspen]
Shrub Layer: 30% cover Vaccinium membranaceum (black huckleberry) Lonicera involucrata (black twinberry) [Viburnum edule (highbush-cranberry)] [Salix spp. (willows)] [Betula glandulosa (scrub birch)] subalpine fir
Herb Layer: 80% cover Cornus canadensis (bunchberry) Lathyrus nevadensis (purple peavine) Calamagrostis canadensis (bluejoint) Arnica cordifolia (heart-leaved arnica) Veratrum viride (Indian hellebore)
Moss Layer: 80% cover Aulacomnium palustre (glow moss) Mnium spp. (leafy mosses) Pleurozium schreberi (red-stemmed feathermoss)
SOIL AND SITE
Moisture Regime: 5-6 (shg-hg) Nutrient Regime: A-B (vp-p)
* Slope Gradient (%): 0-15 * Slope Position: lower and toe
Parent Material: glaciofluvial or morainal Soil Texture: variable Coarse Fragments (%): not available
* Seepage Water: often present * Humus Depth:
DISTRIBUTION: uncommon, and generally found along
generally deep (>10 cm)
edges of wetlands
Aulacomnium palustre
138
Sxw - Scrub birch - Feathermoss (SBSmc2/07)
INTERPRETATIONS
Site limitations: - site and soil conditions of this unit result in marginal forest productivity; serious consideration should be given to excluding logging from this unit.
- sites within this unit with saturated soils are poorly aerated, which slows root development; plant seedlings on naturally or artificially raised microsites.
Silviculture system: - see Section 5.1 - minimize or align slash accumulations when logging
to help meet site preparation objectives and reduce fire hazard.
Site preparation: - scarify to promote natural regeneration on drier sites; other sites see Section 5.2.
Species choice: - Pl, Sb, SX
Vegetation potential: - low
Reforestation: - attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant Pl.
- full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (ie., lop and scatter).
- site conditions may lead to frost damage of regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) is advised.
- sites with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations or dry soil conditions.
Concerns:
139
Sxw - Twinberry - Oak fern
Lonicera involucrata
Gymnocarpium
dryopteris
Mnium spp.
VEGETATION
Tree Layer: 25% cover hybrid white spruce, subalpine fir, [lodgepole pine]
Shrub Layer: 18% cover Lonicera involucrata (black twinberry) Ribes lacustre (black gooseberry) Rosa acicularis (prickly rose) Rubus idaeus (red raspberry) Viburnum edule (highbush-cranberry) hybrid white spruce
Herb Layer: 45% cover Gymnocarpium dryopteris (oak fern) Equisetum arvense (common horsetail) Cornus canadensis (bunchberry) Rubus pubescens (trailing raspberry) Actaea rubra (baneberry) Galium triflorum (sweet-scented bedstraw) Mitella nuda (common mitrewort) Petasites figidus var. palmatus (palmate coltsfoot) Rubus pedatus (five-leaved bramble) Streptopus amplexifolius (clasping twistedstalk) Tiarella trifoliata (three-leaved foamflower) Equisetum sylvaticum (wood horsetail) Calamagrostis canadensis (bluejoint)
Moss Layer: 50% cover Pleurozium schreberi (red-stemmed feathermoss) Hylocomium splendens (step moss) Mnium spp. (leafy mosses) Brachythecium spp. (brachythecium mosses) Ptilium crista-castrensis (knight's plume)
SOIL AND SITE
Moisture Regime: 5-6 (shg-hg) Nutrient Regime: B-D (p-r)
* Slope Gradient (%): 3-10 * Slope Position: * Parent Material: fluvial
Soil Texture: medium Coarse Fragments (%): 0-70
lower or depression
DISTRIBUTION: uncommon; often in areas of cold air accumulation; restricted to southern portion of guide area
140
Sxw - Twinberry - Oakfern (SBSmc2/08)
INTERPRETATIONS
Site limitations: - sites within this unit with saturated soils are poorly aerated, which slows root development; plant seedlings on naturally or artificially raised microsites.
Silviculture system:
Site preparation:
- see Section 5.1
- see Section 5.2
Species choice: - SX, Pl, Bl
Vegetation potential: - moderate to high (black twinberry, thimbleberry, fireweed)
Reforestation: - if vigorous Sx regeneration is present, it should be
- plant sturdy stock as soon after harvesting as
- young Bl regeneration (< 3 m tall) may be susceptible
preserved when feasible.
possible.
to heavy browsing by moose.
Concerns: - sites within this unit with silty soils are susceptible to frost-heaving; bareroot stock will likely resist frost-heaving better than plug stock.
- sites within this unit with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations.
- site conditions may lead to frost damage of Sx and Bl regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a post-resistant species (eg., Pl) is advised.
- Warren’s root collar weevil can cause mortality in young stands, especially where duff layers are thick.
141
Sxw - Devil’s club
Oplopanax horridus
Gymnocarpium
dryopteris
VEGETATION
Tree Layer: 50% cover hybrid white spruce, subalpine fir
Oplopanax horridus (devil's club) Rubus parviflorus (thimbleberry) Ribes lacustre (black gooseberry) [Lonicera involucrata (black twinberry)] subalpine fir [hybrid white spruce]
Herb Layer: 60% cover
Shrub Layer 65% cover
Gymnocarpium dryopteris (oak fern) Cornus canadensis (bunchberry) Rubus pedatus (five-leaved bramble) Streptopus amplexifolius (clasping twistedstalk) [Galium triflorum (sweet-scented bedstraw)] [Tiarella trifoliata (three-leaved foamflower)]
Moss Layer: 50% cover Mnium spp. (leafy mosses) Brachythecium spp. (brachythecium mosses) Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) Barbilophozia lycopodiodes (common leafy liverwort)
SOIL AND SITE
Moisture Regime: 5-6 (shg-hg)
Slope Gradient (%): 2-56 Nutrient Regime: D-E (r-vr)
lower - toe * Slope Position: Parent Material: variable Soil Texture: variable Coarse Fragments (%): not available
DISTRIBUTION: common but localized; more common in northern portions of guide area
Mnium spp.
142
Sxw - Devil’s club (SBSmc2/09)
INTERPRETATIONS
Site limitations: - sites within this unit with saturated soils are poorly aerated, which slows root development; plant seedlings on naturally or artificially raised microsites.
- sites within this unit with medium- to fine-textured lacustrine soils often have poor soil structure, leading to poor root growth; plant stock that will achieve better lateral root development (eg., Cu-treated), prescribe natural regeneration, or protect advance regeneration.
Silviculture system:
Site preparation:
- see Section 5.1
- see Section 5.2
Species choice: - SX, [Bl, Pl]
Vegetation potential:
Reforestation:
- high (black twinberry, thimbleberry, fireweed)
- try to preserve advance regeneration if it is abundant and likely to release and form an acceptable stand.
- advance Bl regeneration should only be accepted if it is likely to reach management objective before it is 150 years old.
- young Bl regeneration (< 3 m tall) may be susceptible to heavy browsing by moose.
- fill-planting will likely be required if a partial cutting silviculture system is used.
- if advance regeneration is unacceptable, plant sturdy stock as soon after harvesting as possible.
- planting Sx in obvious frost pockets should be avoided unless risk can be reduced by providing cover.
Concerns: - sites with thick organic horizons (> 10 cm) and/or shallow (< 30 cm) effective rooting depth have increased windthrow hazard; block layouts must have windfirm boundaries, or a wide buffer of standing timber must be left around such sites.
- site conditions may lead to frost damage of regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) is advised.
- sites with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations or dry soil conditions.
143
Sxw - Horsetail
Lonicera involucrata
Equisetum arvense
VEGETATION
Tree Layer: 50% cover hybrid white spruce, subalpine fir, [lodgepole pine]
Shrub Layer: 50% cover Lonicera involucrata (black twinberry) Ribes lacustre (black gooseberry) [Alnus tenuifolia (mountain alder)] [Viburnum edule (highbush-cranberry)] subalpine fir [hybrid white spruce]
Herb Layer: 80% cover Equisetum arvense (common horsetail) Equisetum sylvaticum (wood horsetail) Equisetum pratense (meadow horsetail) Tiarella trifoliata (three-leaved foamflower) Gymnocarpium dryopteris (oak fern) Cornus canadensis (bunchberry) Rubus pedatus (five-leaved bramble) Streptopus amplexifolius (clasping twistedstalk) Rubus pubescens (trailing raspberry)
Moss Layer: 70% cover Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) [Brachythecium spp. (brachythecium mosses)] [Mnium spp. (leafy mosses)]
SOIL AND SITE
Moisture Regime: 6-7 (hg-shd) Nutrient Regime: B-E (p-vr) Slope Gradient (%): 0-10 Slope Position: toe and depressions Parent Material: variable Soil Texture: variable Coarse Fragments (%): not available
DISTRIBUTION: common in northern portions of guide area
Gymnocarpium
dryopteris
144
Sxw - Horsetail (SBSmc2/10)
INTERPRETATIONS
Site limitations: - very difficult sites to manage; serious consideration should be given to managing these sites as wildlife corridors.
- sites within this unit with saturated soils are poorly aerated, which slows root development; plant seedlings on naturally or artificially raised microsites.
Silviculture system:
Site preparation:
- see Section 5.1
- see Section 5.2 - creating an excessive number of mounds (eg.,
>300/ha) should be avoided, especially on sites within this unit with a water table < 30 cm from the surface.
Species choice:
Vegetation potential:
Reforestation:
- Sx, [Pl Bl]
- high (black twinberry, fireweed, bluejoint)
- advance regeneration should be preserved. - supplement advance regeneration by planting sturdy
- young Bl regeneration (< 3 m tall) may be susceptible stock in groups on available raised microsites.
to heavy browsing by moose.
Concerns: - site conditions may lead to frost damage of regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) is advised.
- these units may represent important wildlife and fish habitat, so prescription should be discussed with fish and wildlife personnel.
- water table will likely rise above the ground surface in the spring, causing seedling mortality.
- this association is critical to the control of runoff streamflow.
- sites within this unit with thick organic horizons (> 10 cm) have an extreme windthrow hazard; block layouts must have windfirm boundaries, or a wide buffer of standing timber must be left around such sites.
145
Sxw - Horsetail - Glowmoss
Lonicera involucrata
Equisetum arvense
Mnium spp.
VEGETATION
Tree Layer: 20% cover hybrid white spruce, subalpine fir, lodgepole pine
Shrub Layer: 10% cover Lonicera involucrata (black twinberry) Ribes lacustre (black gooseberry) Vaccinium membranaceum (black huckleberry) Viburnum edule (highbush-cranberry) [Rubus parviflorus (thimbleberry)] [subalpine fir] [hybrid white spruce]
Herb Layer: 70% cover Cornus canadensis (bunchberry) Mitella nuda (common mitrewort) Rubus pubescens (trailing raspberry) Streptopus amplexifolius (clasping twistedstalk) Listem cordata (heart-leaved twayblade) Equisetum arvense (common horsetail) Athyrium filix-femina (lady fern) Carex disperma (soft-leaved sedge) Aster foliaceus (leafy aster) Calamagrostis canadensis (bluejoint) Galium triflorum (sweet-scented bedstraw) Senecio triangularis (arrow-leaved groundsel)
Moss Layer: 55% cover Ptilium crista-castrensis (knight’s plume) Pleurozium schreberi (red-stemmed feathermoss) Mnium spp. (leafy mosses) [Hylocomium splendens (step moss)] [Aulacomnium palustre (glow moss)]
SOIL AND SITE
Moisture Regime: 6-7 (hg-shd) Nutrient Regime: B-E (p-vr) Slope Gradient (%): 0-30, usually < 10
Slope Position:
Parent Material: variable Soil Texture: medium to fine Coarse Fragments (%): 0-55
lower to toe, level, or depression
DISTRIBUTION: uncommon, and small in size
146
Sxw - Horsetail - Glowmoss (SBSmc2/11)
INTERPRETATIONS
Site limitations: - very difficult sites to manage; serious consideration should be given to managing these sites as wildlife corridors.
- sites within this unit with saturated soils are poorly aerated, which slows root development; plant
seedlings on naturally or artificially raised microsites.
- see Section 5.1
- see Section 5.2 - creating an excessive number of mounds (eg.,
>300/ha) should be avoided, especially on sites within this unit with a water table < 30 cm from the surface.
Silviculture system:
Site preparation:
Species choice: - SX, [Pl, Bl]
Vegetation potential:
Reforestation:
- high (black twinberry, fireweed, bluejoint)
- advance regeneration should be preserved. - supplement advance regeneration by planting sturdy
- young Bl regeneration (< 3 m tall) may be susceptible stock in groups on available raised microsites.
to heavy browsing by moose.
Concerns: - site conditions may lead to frost damage of Sx and Bl regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) is advised.
- these units may represent important wildlife and fish habitat, so prescription should be discussed with fish and wildlife personnel.
- water table will likely rise above the ground surface in the spring, causing seedling mortality.
- this association is critical to the control of runoff stre am flow.
- sites within this unit with thick organic horizons (> 10 cm) have extreme windthrow hazard; block layouts must have windfirm boundaries, or a wide buffer of standing timber must be left around such sites.
147
SbSxw - Scrub birch - Sedge
Betula glandulosa
Carex spp.
VEGETATION
Tree Layer: 20% cover black spruce, hybrid white spruce, [subalpine fir]
Shrub Layer: 50% cover Viburnum edule (highbush-cranberry)
Betula glandulosa (scrub birch) [Lonicera involucrata (black twinberry)] [Spiraea douglasii ssp. menziesii (pink spirea)] [Ledum groenlandicum (Labrador tea)] [black spruce]
Carex spp. (sedges) Cornus canadensis (bunchberry) Calamagrostis canadensis (bluejoint) [Equisetum arvense (common horsetail)] [Oxycoccus oxycoccos (bog cranberry)]
Sphagnum spp. (sphagnums) Tomenthypnum nitens Aulacomnium palustre (glow moss) Mnium spp. (leafy mosses) [Drepanocladus spp. (drepanocladus mosses)]
Salix spp. (willows)
Herb Layer: 70% cover
Moss Layer: 65% cover
(golden fuzzy fen moss)
SOIL AND SITE
Moisture Regime: 7 (shd) Nutrient Regime: B-E (p-vr)
Slope Gradient (%): 0 Slope Position: level and depressions Parent Material: organic Soil Texture: organic Coarse Fragments (%): 0
DISTRIBUTION: common at lower elevations; associated with depressional landscape
Sphagnum spp.
148
SbSxw - Scrub birch - Sedge (SBSmc2/12)
INTERPRETATIONS
Site limitations: - site and soil conditions of this unit result in marginal forest productivity; serious consideration should be given to excluding logging from this unit.
Silviculture system: - avoid logging
149
Cleck here for next page
4.5 Kluskus Moist Cold Sub-Boreal Spruce 14
Location The SBSmc3 occurs on the plateau area between the Nulki Hills in the north and the Naglico Hills in the south. It occurs above either the SBSdw3 or SBSdk. At its upper limits it is bordered by a thin band of SBSmc2 on warm aspects and the ESSFmv1 on cool aspects.
Elevation range 975 - 1200 m
Climate The SBSmc3 has the coldest and shortest growing season of all the SBS biogeoclimatic units in the guide area. This is mostly due to its position on a relatively high plateau in the lee of the Coast Mountains. It is intermediate in precipitation, with a high proportion falling as snow (Table 8).
Soils, geology, and landforms Bedrock types in this subzone include Mesozoic intrusives, volcanics, and sediments, and younger Tertiary volcanics. Parent materials are dominantly morainal, with gravelly loam and clay loam textures. The associated soils are Gray Luvisols, including Brunisolic Gray Luvisols. Colluvial materials are less widespread, and have Dystric Brunisols and Humo-Ferric Podzols with coarser textures (gravelly sandy loam and loamy sand).
Distinguishing the SBSmc3 from adjoining biogeoclimatic units SBSdk has: • trembling aspen but no subalpine fir in the canopy; and • purple peavine but no five-leaved bramble in the herb layer. SBSdw3 has: • Douglas-fir but less subalpine fir in the canopy; • saskatoon in the shrub layer; and • false sarsaparilla but less palmate coltsfoot in the herb layer. SBSmc2 has: • more five-leaved bramble but less palmate coltsfoot; and • devil’s club and oak fern but less fringed aster on wetter sites
Forests Climax forests are dominated by hybrid white spruce and subalpine fir. Lodgepole pine dominates on drier sites. Black spruce occurs in wetlands, and on upland sites with poor soils in combination with lodgepole pine. Black cottonwood occurs along streams and rivers and is often associated with hybrid white spruce.
Wildlife Dry pine-dominated sites east of the Fawnie Mountain Range provide critical winter habitat for woodland caribou. Shrub-dominated wetlands below 1000 m elevation provide important winter habitat for moose. This wetland habitat also
14 Formerly SBSi
150
supports furbearers such as beaver, muskrat, mink, and otter. Sub-boreal coniferous forests are used by moose, mule deer, grizzly bear, black bear, white- tailed deer, spruce grouse, and furbearers, such as wolverine, marten, and red squirrel.
151
Soil Nutrient Regime
Very Poor Poor Medium Rich Very Rich
A B C D E
Very Xeric 0
Xeric 1
Subxeric 2
Submesic 3
Mesic 4
Subhygric 5
Hygric 6
Subhydric 7
01 Sxw - Huckleberry
02 Pl- Juniper - Dwarf
03 P1- Feathermoss - Cladina 08 Sxw - Horsetail
04 Sxw - Huckleberry -
05 Sb - Huckleberry - Spirea
06 SbPl - Feathermoss
blueberry 07 Sxw - Twinberry
09 SbSxw - Scrub birch -
Soopolallie Sedge
FIGURE 17. Edatopic grid displaying site units in the SBSmc3 variant.
152
Site Units 02 03 04 05 01 06 07 08 09
Trees Pinus contorta
Picea mariana
Picea glauca x engelmannii
Rosa acicularis
Juniperus communis
Shepherdia canadensis
Vaccinium membranaceum
Lonicera involucrata
Ledum groenlandicum
Corn us canadensis
Arctostaphylos uva-ursi
Oryzopsis asperifolia
Aster conspicuus
Petasites frigidus var. palmatus Empetrum nigrum
Aster ciliolatus
Equisetum arvense
Carex spp.
Hylocomium splendens
Cladina spp.
Mnium spp.
Sphagnum spp.
Shrubs
Herbs and Dwarf Shrubs
Mosses and Lichens
lodgepole pine
black spruce
hybrid white spruce
prickly rose
common juniper
soopolallie
black huckleberry
black twinberry
Labrador tea
bunch berry
kinnikinnick
rough-leaved ricegrass
showy aster
palmate coltsfoot
crowberry
fringed aster
common horsetail
sedges
step moss
cladina lichens
leafy mosses
sphagnum mosses
FIGURE 18. SBSmc3 vegetation table. Prominence class:
1a Black spruce present; poor tree productivity; Empetrum nigrum (p. 79) 15
or Salix spp. (pp. 63-77) present.
2a Canopy dominated by black spruce; on wet organic soils; moss layer dominated by Sphagnum spp. (p. 312)
SBSmc3/09
Canopy dominated by lodgepole pine or hybrid white spruce; on mineral soils; moss layer dominated by feathermosses.
3a
2b
Seepage water often present; Ledum groenlandicum (p. 40) generally moderate cover (> 3%).
SBSmc3/06
Seepage water never present; Ledum groenlandicum rare or absent.
SB Smc3/05
Black spruce absent; moderate tree productivity; Empetrum nigrum or Salix spp. rare or absent.
4a
3b
1b
Generally midslope to toe or level; if level, seepage water often present; Lonicera involucrata (p. 48) and Petasites frigidus var. palmatus (p. 114) present.
5a Water table generally present within 50 cm; Equisetum spp. (p. 280) abundant (> 15%).
SBSmc3/08
Water table absent; Equisetum spp. low cover (< 1%) or absent.
6a Generally midslope or level; Lonicera involucrata generally low cover (< 3%) or absent.
SBSmc3/01
6b Generally mid- to lower slope; Lonicera involucrata
SBSmc3/07
Mid- to upper slope or level; if level, seepage water never present; Lonicera involucrata and Petasites frigidus var. palmatus generally rare or absent.
7a
5b
moderate (> 3%) to high cover.
4b
Shrub layer dominated by Juniperus communis (p. 51); on shallow soils over bedrock.
SBSmc3/02
Juniperus communis low cover or absent; soils reasonably deep (> 50 cm).
7b
15 Page numbers refer to the publication Plants of Northern British Columbia (MacKinnon et al. 1992)
154
8a Upper slope to crest or level; Arctostaphylos uva-ursi (p. 82) abundant.
SBSmc3/03
8b Generally midslope on south aspects; Arctostaphylos
SBSmc3/04 uva-ursi rare or absent.
155
Sxw - Huckleberry
Rosa acicularis
Petasites frigidus
var. palmatus
Ptilium crista-castrensis
VEGETATION
Tree Layer: 40% cover hybrid white spruce, lodgepole pine
Rosa acicularis (prickly rose) Lonicera involucrata (black twinberry) Vaccinium membranaceum (black huckleberry) Viburnum edule (highbush-cranberry) Spiraea betulifolia (birch-leaved spirea) hybrid white spruce subalpine fir
Shrub Layer: 30% cover
Herb Layer: 40% cover Cornus canadensis (bunchberry) Petasites frigidus var. palmatus (palmate coltsfoot) Arnica cordifolia (heart-leaved arnica) Linnaea borealis (twinflower) Orthilia secunda (one-sided wintergreen) Calamagrostis canadensis (bluejoint) Rubus pubescens (trailing raspberry) Vaccinium caespitosum (dwarf blueberry) Epilobium angustifolium (fireweed)
Moss Layer: 95% cover Ptilium crista-castrensis (knight’s plume) Pleurozium schreberi (red-stemmed feathermoss) Hylocomium splendens (step moss) Peltigera aphthosa (freckle lichen)
SOIL AND SITE
Moisture Regime: 4 (m) Nutrient Regime: B-D (p-r) Slope Gradient (%): 0-37
* Slope Position: mid or level
glaciofluvial medium - moderately coarse
Parent Material: morainal; occasionally
* Soil Texture: Coarse Fragments (%): 10-90
COMMENTS: this association dominates the landscape, especially long basal till (morainal) slopes
DISTRIBUTION: very common, widespread and often large
156
Sxw - Huckleberry (SBSmc3/01)
INTERPRETATIONS
Site limitations: - cold soils will limit root growth, especially on sites with humus layers >10 cm deep; plant on naturally or artificially raised microsites.
Silviculture system:
Site preparation:
- see Section 5.1
- see Section 5.2 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
- harvest fine-textured moraines during the dry part of the summer or in winter.
Species choice: - Pl, SX, Bl
Vegetation potential: - low
Reforestation: - attempt to regenerate naturally if potential exists. - i f natural regeneration is not feasible, plant a
mixture of Pl and Sx. - young Bl regeneration (< 3 m tall) may be susceptible
to heavy browsing by moose. - help maintain stand diversity in areas to be planted
with Pl by mapping aspen patches prior to harvest and planting these areas to spruce.
Concerns: - site conditions may lead to frost damage of regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) is advised.
- full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (ie., lop and scatter)
- sites within this unit with thick organic horizons and/or shallow (< 30 cm) effective rooting depth have increased windthrow hazard; block layouts must have windfirm boundaries, or a wide buffer of standing timber must be left around such sites.
157
Juniperus communis
Vaccinium caespitosum
Pl - Juniper - Dwarf huckleberry
VEGETATION
Tree Layer: 15% cover lodgepole pine
Shrub Layer: 60% cover Juniperus communis (common juniper) Rosa acicularis (prickly rose) Amelanchier alnifolia (saskatoon) [paper birch]
Herb Layer: 25% cover Vaccinium caespitosum (dwarf blueberry) Linnaea borealis (twinflower) Arctostaphylos uva-ursi (kinnikinnick) Fragaria virginiana (wild strawberry) [Cornus canadensis (bunchberry)]
Moss Layer: 35% cover Pleurozium schreberi (red-stemmed feathermoss) Dicranum polysetum (wavy-leaved moss)
SOIL AND SITE
Moisture Regime: 1 (x) Nutrient Regime: A-B (vp-p)
Slope Position: upper
Slope Gradient (%): 20-40
* Parent Material:
* Soil Texture: coarse * Coarse Fragments (%): 70-90
variable, but bedrock usually close to surface
COMMENTS: this association occurs on shallow soils over bedrock
DISTRIBUTION: rare
Pleurozium schreberi
158
Pl - Juniper - Dwarf huckleberry (SBSmc3/02)
INTERPRETATIONS
Site limitations: - site and soil conditions of this unit result in marginal forest productivity; serious consideration should be given to excluding logging from this unit.
Silviculture system: - avoid logging
159
Pl - Feathermoss - Cladina
Arctostaphylos uva-ursi
Pleurozium schreberi
Cladina rangiferina
VEGETATION
Tree Layer: 30% cover lodgepole pine
Shrub Layer: 15% cover Shepherdia canadensis (bunchberry) Rosa acicularis (prickly rose) Juniperus communis (common juniper) Spiraea betulifolia (birch-leaved spirea) Shepherdia canadensis (soopolallie) lodgepole pine subalpine fir hybrid white spruce
Herb Layer: 35% cover Arctostaphylos uva-ursi (kinnikinnick) Linnaea borealis (twinflower) Cornus canadensis (bunchberry) Vaccinium caespitosum (dwarf blueberry) Oryzopsis asperifolia (rough-leaved ricegrass) Fragaria virginiana (wild strawberry) Galium boreale (northern bedstraw) Pyrola chlorantha (green wintergreen)
Moss Layer: 80% cover Pleurozium schreberi (red-stemmed feathermoss) Peltigera aphthosa (freckle lichen) Peltigera malacea (apple pelt) Dicranum polysetum (wavy-leaved moss) Dicranum fuscescens (curly heron’s-bill moss) Cladina rangiferina (grey reindeer lichen) Cladina mitis (green reindeer lichen) Cladonia gracilis (black foot cladonia) Cladonia chlorophaea (fairy cup lichen) Stereocaulon tomentosum (woolly coral lichen) Polytrichum commune
SOIL AND SITE
Moisture Regime: 2 (sx) Nutrient Regime: A-B (vp-p) Slope Gradient (%): 0-15 (usually 0)
* Slope Position: * Parent Material: glaciofluvial * Soil Texture: coarse
Coarse Fragments (%): 45-70
upper slope - crest, or level
DISTRIBUTION: common on coarse-textured fluvial or glaciofluvial terraces
160
Pl - Feathermoss - Cladina (SBSmc3/03)
INTERPRETATIONS
Site limitations: - site and soil conditions of this unit result in marginal forest productivity; serious consideration should be given to excluding logging from this unit.
- sites within this unit with high coarse fragment content (> 70%) will have significantly reduced soil moisture retention and will be extremely difficult to plant; attempt to regenerate naturally by retaining Pl cones.
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
Site preparation: - light scarification for seedbed preparation or summer logging with no site preparation.
Species choice: - Pl, (Sx)
Vegetation potential: - low
Reforestation: - attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant Pl. - Sx is less productive than Pl on these sites.
- full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (ie., lop and scatter).
- site and soil conditions of this unit result in drought hazard for a significant portion of the growing season; natural regeneration is generally more adapted to surviving these conditions, especially during establishment.
Concerns:
161
Sxw - Huckleberry - Soopolallie
Shepherdia canadensis
Aster conspicuus
Arnica cordifolia
VEGETATION
Tree Layer: 40% cover lodgepole pine, hybrid white spruce
Shepherdia canadensis (soopolallie) Spiraea betulifolia (birch-leaved spirea) Rosa acicularis (prickly rose) Viburnum edule (highbush-cranberry) Vaccinium membranaceum (black huckleberry) Alnus crispa ssp. sinuata hybrid white spruce
Herb Layer: 55% cover
Shrub Layer: 50% cover
(Sitka alder)
Aster conspicuus (showy aster) Cornus canadensis (bunchberry) Arnica cordifolia (heart-leaved arnica) Epilobium angustifolium (fireweed) Linnaea borealis (twinflower) Orthilia secunda (one-sided wintergreen) Vaccinium caespitosum (dwarf blueberry) Fragaria virginiana (wild strawberry) Calamagrostis canadensis (bluejoint)
Moss Layer: 85% cover Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) Peltigem aphthosa (freckle lichen) Dicranum polysetum (wavy-leaved moss) Dicranum fuscescens (curly heron’s-bill moss)
SOIL AND SITE
Moisture Regime: 3 (sm) Nutrient Regime: B-C (p-m)
* Aspect: * Slope Gradient (%): 2-55
usually SE - SW
* Slope Position: mid - upper
morainal or lacustrine Parent Material: glaciofluvial, occasionally
Soil Texture: variable Coarse Fragments (%): 0-85
DISTRIBUTION: common on warm aspects
162
Sxw - Huckleberry - Soopolallie (SBSmc3/04)
INTERPRETATIONS
Site limitations: - sites within this unit with high coarse fragment content (> 70%) will have significantly reduced soil moisture retention and will be extremely difficult to plant; attempt to regenerate naturally by retaining Pl cones.
Silviculture system:
Site preparation:
- see Section 5.1
- light scarification for seedbed preparation or summer logging with no site preparation
Species choice:
Vegetation potential: - low
Reforestation:
- Pl, Sx, (Bl)
- attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant Pl. - plant Sx and Bl only on moister microsites. - young Bl regeneration (< 3 m tall) may be susceptible
to heavy browsing by moose.
Concerns: - full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (ie., lop and scatter).
- site and soil conditions of this unit result in drought hazard for a significant portion of the growing season; natural regeneration is generally more adapted to surviving these conditions, especially during establishment.
- sites within this unit with shallow and/or coarse textured soils are vulnerable to nutrient deficiency if forest floors are reduced; site preparation methods that reduce forest floor thickness, such as slashburning or brushblading, must be avoided.
- mountain pine beetle may cause mortality in large- diameter lodgepole pine stands of age class > 7.
163
Sb - Huckleberry - Spirea
Rosa acicularis
Empetrum nigrum
VEGETATION
Tree Layer: 40% cover lodgepole pine, black spruce, hybrid white spruce
Shrub Layer: 40% cover Rosa acicularis (prickly rose) Vaccinium membranaceum (black huckleberry) Shepherdia canadensis (soopolallie) Spiraea betulifolia (birch-leaved spirea) hybrid white spruce subalpine fir black spruce
Herb Layer: 35% cover Vaccinium caespitosum (dwarf blueberry) Cornus canadensis (bunchberry) Arnica cordifolia (heart-leaved arnica) Linnaea borealis (twinflower) Empetrum nigrum (crowberry) Epilobium angustifolium (fireweed)
Moss Layer: 85% cover Pleurozium schreberi (red-stemmed feathermoss) Peltigera aphthosa (freckle lichen) Cladina rangiferina (grey reindeer lichen) Cladina mitis (green reindeer lichen)
SOIL AND SITE
Moisture Regime: 3-4 (sm-m) Nutrient Regime: A-B (vp-p)
Slope Gradient (%): 0-5 * Aspect north-facing if sloping
* Slope Position: upper or level Parent Material: morainal, glacio(fluvial) Soil Texture: coarse - medium Coarse Fragments (%): 0-65, generally > 40
COMMENTS: these sites are similar to, but slightly drier than, the SBSmc3/06
DISTRIBUTION: common, widespread and often large
Cladina rangiferina
164
Sb - Huckleberry - Spirea (SBSmc3/05)
INTERPRETATIONS
Site limitations: - soils are saturated in the spring, but may experience drought in summer, both resulting in poor root development; the poor productivity resulting from these limitations should dictate a limited intensive silvicultural investment.
- compact soil layers and/or low aeration porosity associated with fine-textured soils will reduce rooting depth and decrease productivity over a rotation; regenerate naturally whenever possible.
- cold soils will limit root growth, especially on sites with humus layers >10 cm deep; plant on naturally or artificially raised microsites.
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
- harvest fine-textured moraines during the dry part of the summer or in winter.
Site preparation: - see Section 5.2
Species choice: - Pl, (Sx, Sb)
Vegetation potential: - low
Reforestation: - attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant Pl. - Sx and Sb are generally less productive than Pl on
these sites.
Concerns: - full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones
should be distributed across these sites (ie., lop and scatter).
- sites within this unit with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations or dry soil conditions.
- site conditions may lead to frost damage of regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) is advised.
165
SbPl - Feathermoss
Lonicera involucrata
Ledum groenlandicum
Empetrum nigrum
VEGETATION
, Tree Layer: 40% cover lodgepole pine, black spruce, hybrid white spruce
Lonicera involucrata (black twinberry) Rosa acicularis (prickly rose) Ledum groenlandicum (Labrador tea) Shepherdia canadensis (soopolallie) Vaccinium membranaceum (black huckleberry) hybrid white spruce black spruce subalpine fir
Cornus canadensis (bunchberry) Vaccinium caespitosum (dwarf blueberry) Petasites frigidus var. palmatus (palmate coltsfoot) Empetrum nigrum (crowberry) Linnaea borealis (twinflower) Aster ciliolatus (fringed aster)
Shrub Layer: 40% cover
Herb Layer: 35% cover
Moss Layer: 95% cover Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) Cladina rangiferina (grey reindeer lichen) [Hylocomium splendens (step moss)]
SOIL AND SITE
Moisture Regime: 5 (shg) Nutrient Regime: A-B (vp-p)
Slope Gradient (%): 0-7 * Aspect: north-facing if sloping
* Slope Position: lower or level Parent Material: morainal, glacio(fluvial) Soil Texture: coarse - medium Coarse Fragments (%): 30-60
* Seepage Water: occasionally present
COMMENTS: these sites are slightly poorer than the SBSmc3/07 and have more lodgepole pine in the canopy
DISTRIBUTION: uncommon, and usually associated with wetlands
166
SbPl - Feathermoss (SBSmc3/06)
INTERPRETATIONS
Site limitations: - soils are saturated in the spring, but may experience drought in summer, both resulting in poor root development; the poor productivity resulting from these limitations should dictate a limited intensive silvicultural investment.
- compact soil layers and/or low aeration porosity associated with fine-textured soils will reduce rooting depth and decrease productivity over a rotation; regenerate naturally whenever possible.
- sites within this unit with saturated soils are poorly aerated, which slows root development; plant seedlings on naturally or artificially raised microsites.
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
- harvest fine-textured moraines during the dry part of the summer or in winter.
Site preparation: - see Section 5.2
Species choice: - Pl, (Sx, Sb)
Vegetation potential: - low
Reforestation: - attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant Pl. - Sx and Sb are generally less productive than Pl on
these sites.
Concerns: - full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (ie., lop and scatter)
- sites within this unit with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations or dry soil conditions.
- site conditions may lead to frost damage of regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) is advised.
167
Sxw - Twinberry
Lonicera involucrata
Rosa acicularis
Rubus pubescens
VEGETATION
Tree Layer: 40% cover hybrid white spruce, lodgepole pine
Lonicera involucrata (black twinberry) Rosa acicularis (prickly rose) Ribes lacustre (black gooseberry) Vaccinium membranaceum (black huckleberry) Viburnum edule (highbush-cranberry) hybrid white spruce
Herb Layer: 60% cover Cornus canadensis (bunchberry) Rubus pubescens (trailing raspberry) Petasites frigidus var. palmatus (palmate coltsfoot) Fragaria virginiana (wild strawberry) Linnaea borealis (twinflower) Mitella nuda (common mitrewort) Aster ciliolatus (fringed aster) Arnica cordifolia (heart-leaved arnica) Epilobium angustifolium (fireweed) Galium boreale (northern bedstraw)
Shrub Layer: 35% cover
Moss Layer: (75% cover) Hylocomium splendens (step moss) Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) Peltigera aphthosa (freckle lichen)
SOIL AND SITE
Moisture Regime: 5 (shg) Nutrient Regime: C-D (m-r)
* Slope Gradient (%): 0-22 * Slope Position: mid - toe (occasionally level)
Parent Material: morainal, (g1acio)fluvial Soil Texture: variable Coarse Fragments (%): 15-80
* Seepage Water: occasionally present
DISTRIBUTION: common, especially on lower slope positions
168
Sxw - Twinberry (SBSmc3/07)
INTERPRETATIONS
Site limitations: - sites within this unit with saturated soils are poorly aerated, which slows root development; plant seedlings o n naturally or artificially raised microsites.
- see Section 5.1
- see Section 5.2
Silviculture system:
Site preparation:
Species choice: - Pl, SX, Bl
Vegetation potential:
Reforestation:
- very high (fireweed, black twinberry)
- if vigorous advance regeneration is present it should be preserved when feasible.
- plant sturdy stock as soon after harvesting as possible.
- young Bl regeneration (< 3 m tall) may be susceptible to heavy browsing by moose.
- help maintain stand diversity in areas to be planted with Pl by mapping aspen patches prior to harvest and planting these areas to spruce.
Concerns: - sites within this unit with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations or dry soil conditions.
- site conditions may lead to frost damage of regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) i s advised.
- possible windthrow hazard if effective rooting depth < 30 cm.
- Warren’s root collar weevil can cause mortality in young stands, especially where duff layers are thick.
169
Sxw - Horsetail
Lonicera involucrata
Equisetum arvense
Hylocomium splendens
VEGETATION
Tree Layer: 40% cover hybrid white spruce
Shrub Layer: 35% cover Lonicera involucrata (black twinberry) Ribes lacustre (black gooseberry) Ribes triste (red swamp currant) Viburnum edule (highbush-cranberry) Rosa acicularis (prickly rose) hybrid white spruce
Herb Layer: 90% cover Equisetum arvense (common horsetail) Cornus canadensis (bunchberry) Rubus pubescens (trailing raspberry) Petasites frigidus var. palmatus (palmate coltsfoot)
Mitella nuda (common mitrewort) Linnaea borealis (twinflower) Cicuta douglasii (Douglas’ water-hemlock) Aster ciliolatus (fringed aster) Epilobium angustifolium (fireweed) Galium triflorum (sweet-scented bedstraw) Galium boreale (northern bedstraw) Platanthem obtusata (one-leaved rein-orchid) Fragaria virginiana (wild strawberry)
,
Moss Layer: 80% cover Hylocomium splendens (step moss) Pleurozium schreberi (red-stemmed feathermoss) Mnium spp. (leafy mosses) Ptilium crista-castrensis (knight’s plume) Peltigera aphthosa (freckle lichen)
SOIL AND SITE
Moisture Regime: 6 (hg) Nutrient Regime: C-D (m-r) Slope Gradient (%): 0-7
* Slope Position: * Parent Material: fluvial
Soil Texture: coarse - medium Coarse Fragments (%): 20-65
* Seepage Water: generally present
DISTRIBUTION: common, but small in size and
toe, depression or level
associated with streams or rivers
170
Sxw - Horsetail (SBSmc3/08)
INTERPRETATIONS
Site limitations: - very difficult sites to manage; serious consideration should be given to managing these sites as wildlife corridors.
- sites within this unit with saturated soils are poorly aerated, which slows root development; plant seedlings on naturally or artificially raised microsites.
- see Section 5.1
- see Section 5.2 -creating an excessive number of mounds (eg.,
>300/ha) should be avoided, especially on sites within this unit with a water table < 30 cm from the surface.
Silviculture system:
Site preparation:
Species choice: - SX, [Bl, Pl]
Vegetation potential: - high to very high (black twinberry, prickly rose, fireweed)
Reforestation: - advance regeneration should be preserved. - supplement advance regeneration by planting sturdy
- young Bl regeneration (< 3 m tall) may be susceptible stock in groups on available raised microsites.
to heavy browsing by moose.
Concerns: - these units may represent important wildlife habitat, so prescription should be discussed with fish and wildlife personnel.
- site conditions may lead to frost damage of regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) is advised.
(> 10 cm) increase the windthrow hazard; block layouts must have windfirm boundaries, or a wide buffer of standing timber must be left around such sites.
- water table will likely rise above the ground surface in the spring, causing seedling mortality.
- this association is critical to the control of runoff and streamflow.
- sites within this unit with thick organic horizons
171
SbSxw - Scrub birch - Sedge
Betula glandulosa
Carex spp.
VEGETATION
Tree Layer: 20% cover black spruce, hybrid white spruce, [subalpine fir]
Shrub Layer: 50% cover Viburnum edule (highbush-cranberry)
Betula glandulosa (scrub birch) [Lonicera involucrata (black twinberry)] [Spiraea douglasii ssp. menziesii (pink spirea)] [Ledum groenlandicum (Labrador tea)] [black spruce]
Salix spp. (willows)
Herb Layer: 70% cover Carex spp. (sedges) Cornus canadensis (bunchberry) Calamagrostis canadensis (bluejoint) [Equisetum arvense (common horsetail)] [Oxycoccus oxycoccos (bog cranberry)]
Moss Layer: 65% cover Sphagnum spp. (sphagnums) Tomenthypnum nitens Aulacomnium palustre (glow moss) Mnium spp. (leafy mosses) [Drepanocladus spp. (drepanocladus mosses)]
(golden fuzzy fen moss)
SOIL AND SITE
Moisture Regime: 7 (shd) Nutrient Regime: B-C (p-m) Slope Gradient (%): 0 Slope Position: level and depressions Parent Material: organic Soil Texture: organic Coarse Fragments (%): 0
DISTRIBUTION: common at lower elevations; associated with depressional landscape
Sphagnum spp.
172
SbSxw - Scrub birch - Sedge (SBSmc3/09)
INTERPRETATIONS
~ - Site limitations: - site and soil conditions of this unit result in marginal forest productivity; serious consideration should be given to excluding logging from this unit.
Silviculture system: - avoid logging
173
4.6 Mossvale Moist Cool Sub-Boreal Spruce 16
Location The SBSmk1 occurs on a large plateau northwest of Prince George and in some valleys in the interior of the Omineca Mountains (Figure 1). It is bordered by the SBSwk1 on its eastern boundary, the SBSdw3 on its southern and western boundaries, and the BWBSdk1 at its northern boundary. At its upper elevational extent it borders the ESSF'mv3.
Elevation range 750 - 1070 m
Climate The SBSmk1 is intermediate with respect to precipitation and temperature, in comparison with other guide units. It is considered to best represent the sub- boreal climate, with relatively long snowy winters and moist cool summers (Table 8).
Soils, geology, and landforms Bedrock geology in this subzone is dominated by volcanic rocks of Mesozoic age, with lesser amounts of metamorphic rocks. Soils have formed on predominantly morainal and lacustrine materials. Morainal deposits usually have gravelly loam and clay textures, associated with Gray Luvisolic soils, including Brunisolic Gray Luvisols. In the eastern part of the subzone, Humo-Ferric Podzols have formed on morainal deposits in response to moister climatic conditions. Organic soils (Fibrisols) occur in depressional sites in rolling, drumlinized morainal landscapes. Gray Luvisolic soils have formed on fine- textured (silty clay, clay) lacustrine deposits.
Distinguishing the SBSmk1 from adjoining biogeoclimatic units SBSmh has: • more Douglas-fir but less subalpine fir in the canopy; • more beaked hazelnut and less black huckleberry on mesic sites; and • Hooker's fairybells and showy aster but less five-leaved bramble on mesic
SBSdw3 has: • Douglas-fir more common on mesic sites; and • showy aster but less five-leaved bramble and oak fern on mesic sites. SBSmw has: • Douglas-fir more common on mesic sites; and • showy aster but less five-leaved bramble and oakfern on mesic sites. SBSmk2 has: • more highbush-cranberry but less thimbleberry on mesic sites; and • more palmate coltsfoot but less queen’s cup on mesic sites. SRSwk (SBSwk1, SBSwk2, SBSwk3) has: • more devil’s club in the shrub layer on mesic sites; and • more oak fern in the herb layer on mesic sites.
sites.
16 Formerly SBSe2
174
Forests Recurrent disturbances in this variant often lead to forested areas dominated by lodgepole pine and trembling aspen. Climax forests are dominated by hybrid white spruce, with subalpine fir being generally absent. Douglas-fir occurs as a long lived seral species on drier warm aspects with coarse soils often present. Black spruce occurs in wetlands and in combination with lodgepole pine on poorer upland sites. Paper birch occurs sporadically, often in combination with Douglas-fir, and in localized pure stands mostly near Prince George. Black cottonwood occurs along streams and rivers and is often associated with hybrid white spruce.
Wildlife Shrub-dominated wetlands at less than 900 m elevation provide important winter habitat for moose. These wetlands are also used by beaver, muskrat, mink, otter, northern harrier, and in some areas by sandhill cranes. Riparian forests are used by grizzly bear and black bear in the early spring. Moose, white-tailed deer, lynx and ruffed grouse also use this highly productive habitat. Habitats in and around small lakes are used by moose, gray wolf, beaver, muskrat, mink, otter, and birds such as bald eagle, osprey, and cavity nesters. Coniferous sub-boreal forest provides habitat for wolverine, marten, red squirrel, spruce grouse and great horned owl.
175
Soil Nutrient Regime
Very Poor Poor Medium Rich Very Rich
A B C D E
Very Xeric 0
Xeric 1
Subxeric 2
Submesic 3
Mesic 4
Subhygric 5
Hygric 6
Subhydric 7
01 Sxw - Huckleberry - 06 Sb - Huckleberry - Spirea
Highbush cranberry 07 Sxw - Oak fern
02 Pl - Cladina - Step moss 08 Sxw - Devil’s club
03 Pl- Feathermoss - Cladina 09 Sxw - Horsetail
04 SxwFd - Knight’s plume 10 Sb - Scrub birch - Sedge
05 SxwFd - Toad-flax
FIGURE 19. Edatopic grid displaying site units in the SBSmk1 variant.
176
Site Units 02 03 04 05 06 01 07 08 09 10
Trees Pinus contorta
Pseudotsuga menziesii
Picea mariana
Picea glauca x engelmannii
Shepherdia canadensis
Vaccinium myrtilloides
Vaccinium membranaceum
Rubus parviflorus
Oplopanax horridus
Lonicera involucrata
Arctostaphylos uva-ursi
Chimlaphila umbellata
Aster conspicuus
Oryzopsis asperifolia
Clintonia uniflora
Vaccinium caespitosum
Gymnocarpium dryopteris
Athyrium filix-femina
Equisetum arvense
Carex spp.
Cladina rangiferina
Shrubs
Herbs and Dwarf Shrubs
Lichens
lodgepole pine
Douglas-fir
black spruce
hybrid white spruce
soopolallie
velvet-leaved blueberry
black huckleberry
thimbleberry
devil’s club
black twinberry
kinnikinnick
prince’s pine
showy aster
rough-leaved ricegrass
queen’s cup
dwarf blueberry
oak fern
lady fern
common horsetail
sedges
grey reindeer lichen
FIGURE 20. SBSmk1 vegetation table. 1 2 3 4 5
1a Black spruce often present in canopy or if not then a white spruce canopy; very wet sites with a water table within 30 cm or sites with poor forest productivity.
2a Sphagnum spp. (p. 312) 17 present; organic soils.
3a Pure black spruce canopy; a bog. SBSmk1/10
3b Hybrid white spruce and black spruce canopy. SBSmk1/09(b)
2b Sphagnum moss low cover (< 1%) or absent; mineral soils.
4a Canopy dominated by hybrid white spruce with occasional black spruce; adjacent to watercourses; Equisetum spp. (p. 280) moderate to high cover (usually > 5%).
SBSmk1/09(a)
Canopy dominated by lodgepole pine with black spruce; upland sites; Equisetum spp. low cover (< 1%), or absent.
SBSmk1/06
4b
1b Black spruce absent from canopy.
5a Main canopy dominated by lodgepole pine or Douglas-fir.
6a Canopy generally dominated by lodgepole pine; coarse-textured soils or shallow soils (< 50 cm) over bedrock; Cladina spp. (p. 334) and/or Arctostaphylos uva-ursi (p. 82) > 10% cover.
7a On shallow soils over bedrock; moss layer dominated by lichen.
SBSmk1/02
7b Level, coarse-textured fluvial material; Vaccinium
SBSmk1/03
6b Canopy dominated by lodgepole pine or Douglas-fir; soils
myrtilloides (p. 43), and lichens common.
variable; Cladina spp. and Arctostaphylos uva-ursi low cover (< 10%) or absent.
8a Canopy dominated by Douglas-fir; high cover of subalpine fir regeneration; low herb cover (usually < 20%).
SBSmk1/04
17 Page numbers refer to the publication Plants ofNorthern British Columbia (MacKinnon et al. 1992).
178
8b Canopy generally dominated by lodgepole pine; variable amount or subalpine fir regeneration; herb cover moderately well to well developed.
9a Often mid to lower slope, if upper slope, northerly aspect; Rubus parviflorus (p.36) often abundant (> 3%), Gymnocarpium dryopteris (p.293) generally present.
SBSmk1/01
Generally mid to upper slope; Rubus parviflorus and Gymnocarpium dryopteris low cover (< 1%) or absent.
SBSmk1/05
Main canopy either a mixture of lodgepole pine and hybrid white spruce or dominated by hybrid white spruce.
10a Mixed lodgepole pine and white spruce canopy.
9b
5b
11a Lower slope, or mid to steep upper slope with NW to NE aspect, or level and influenced by water table; Gymnocarpium dryopteris moderate to high cover (usually > 20%); Clintonia uniflora (p.131) low cover (< 2%) or absent; Equisetum spp. sometimes present.
SBSmk1/07
11b Usually mid slope, 90° to 270° aspect; or gentle, upper slope and north aspect; Gymnocarpium dryopteris low cover (< 5%) or absent; Clintonia uniflora present; Equisetum spp. usually absent.
SBSmk1/01
10b Main canopy dominated by hybrid white spruce.
12a Moderate to high cover (usually > 15%) of Oplopanax horridus (p.10); lower to toe slope or level, if sloping, often NW to NE aspect.
SBSmk1/08
12b Oplopanax horridus low cover (< 5%) or absent; slope position variable.
13a Lower slope, or mid and steep upper slope, with NW to NE aspect, or level and influenced by water table; Gymnocarpium dryopteris moderate to high cover (usually > 20%); Clintonia uniflora low cover (< 2%) or absent.
SBSmk1/07
13b Usually mid slope, 90° to 270° aspect, or gentle, upper slope and north aspect; Gymnocarpiurn dryopteris absent, or low cover (< 5%); Clintonia uniflora present.
SBSmk1/01
179
Sxw - Huckleberry - Highbush-cranberry
Rubus parviflorus
Clintonia uniflora
Ptilium crista-castrensis
VEGETATION
Tree Layer: 45% cover lodgepole pine, hybrid white spruce, [Subalpine fir]
Rubus parviflorus (thimbleberry) Spiraea betulifolia (birch-leaved spirea) Vaccinium membranaceum (black huckleberry) Lonicera involucrata (black twinberry) Rosa acicularis Ribes lacustre (black gooseberry) Sorbus scopulina (western mountain-ash) Viburnum edule (highbush-cranberry) subalpine fir hybrid white spruce
Herb Layer: 55% cover Cornus canadensis (bunchberry) Clintonia uniflora (queen’s cup) Smilacina racemosa (false Solomon’s-seal) Orthilia secunda (one-sided wintergreen) Lycopodium annotinum (stiff clubmoss) Linnaea borealis (twinflower) Aralia nudicaulis (wild sarsaparilla) Gymnocarpium dryopteris (oak fern)
Shrub Layer: 45% cover
(prickly rose)
Moss Layer: 90% cover Ptilium crista-castrensis (knight’s plume) Pleurozium schreberi (red-stemmed feathermoss) Rhytidiadelphus triquetrus (electrified cat’s-tail moss) Hylocomium splendens (step moss)
SOIL AND SITE
Moisture Regime: 4-5 (m-shg) Nutrient Regime: B-D (p-r)
* Slope Position: usually mid
* Soil Texture:
* Slope Gradient (%): 0-40
Parent Material: morainal and (g1acio)fluvial usually moderately coarse or medium
Coarse Fragments (%): 10-63
DISTRIBUTION: very common, widespread, and often large
180
Sxw - Huckleberry - Highbush-cranberry (SBSmk1/01)
INTERPRETATIONS
Site limitations: - sites within this unit with medium- to fine-textured lacustrine soils often have poor soil structure, leading to poor root growth; plant stock which will achieve better lateral root development (eg. Cu- treated), prescribe natural regeneration, or protect advance regeneration.
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
Site preparation: - see Section 5.2
Species choice: - Pl, SX, Fd, [Bl]
Vegetation potential:
Reforestation:
- moderate (trembling aspen, fireweed, thimbleberry)
- attempt to regenerate naturally if potential exists. - plant Fd only on south-facing coarse-textured sites
within its natural range. - help maintain stand diversity on sites to be planted
with Pl by mapping aspen patches prior to harvest and planting these areas to spruce.
- young Bl regeneration (< 3m tall) may be susceptible to heavy browsing by moose.
- advance Bl regeneration should only be accepted if it is likely to reach management objective before it is 150 years old.
Concerns: - full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (i.e. lop and scatter).
- sites with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations or dry soil conditions.
- spruce weevil constitutes a moderate hazard south of Weedon Lake and east of Great Beaver Lake; consider modifying brush treatments in localized areas with > 5% current attack.
- mountain pine beetle may cause mortality in large diameter lodgepole pine stands of age class > 7.
181
Pl - Cladina - Step moss
Shepherdia canadensis
Vaccinium caespitosum
VEGETATION
Tree Layer: 15% cover lodgepole pine, hybrid white spruce
Shrub Layer: 30% cover Shepherdia canadensis (soopolallie) Rosa acicularis (prickly rose) Amelanchier alnifolia (saskatoon) Spiraea betulifolia (birch-leaved spirea) Prunus pensylvanica (pin cherry) subalpine fir
Herb Layer: 40% cover Linnaea borealis (twinflower) Vaccinium caespitosum (dwarf blueberry) Aralia nudicaulis (wild sarsaparilla) Elymus glaucus (blue wildrye) Galium boreale (northern bedstraw) Disporum trachycarpum (rough-fruited fairybells)
Moss Layer: 95% cover Pleurozium schreberi (red-stemmed feathermoss) Hylocomium splendens (step moss) Cladina spp. (cladina lichens)
SOIL AND SITE
Moisture Regime: 1 (x) Nutrient Regime: A-C (vp-m) Aspect south to west Slope Gradient (%): 14-20
* Slope Position: * Parent Material:
mid to crest morainal veneers over bedrock
Soil Texture: usually medium Coarse Fragments (%): 30-50
DISTRIBUTION: uncommon, small, and always associated with bedrock outcrops
Cladina rangiferina
182
Pl - Cladina - Step moss (SBSmk1/02)
INTERPRETATIONS
Site limitations: - site and soil conditions of this unit result in marginal forest productivity; serious consideration should be given to excluding logging from this unit.
- sites within this unit with high coarse fragment content (> 70%) will have significantly reduced soil moisture retention and will be extremely difficult to plant; attempt to regenerate naturally by retaining Pl cones and/or leaving Fd seed-trees on site.
Silviculture system: - avoid logging.
183
Pl- Feathermoss - Cladina
Vaccinium myrtilloides
Arctostaphylos uva-ursi
Pleurozium schreberi
VEGETATION
Tree Layer: 35% cover lodgepole pine
Vaccinium myrtilloides (velvet-leaved blueberry) Rosa acicularis (prickly rose) Spiraea betulifolia (birch-leaved spirea) Shepherdia canadensis (soopolallie) lodgepole pine hybrid white spruce
Herb Layer: 40% cover
Shrub Layer: 35% cover
Arctostaphylos uva-ursi (kinnikinnick) Cornus canadensis (bunchberry) Linnaea borealis (twinflower) Lycopodium complanatum (ground-cedar) Vaccinium caespitosum (dwarf blueberry) Geocaulon lividum (bastard toad-flax) Melampyrum lineare (cow-wheat) Vaccinium caespitosum (dwarf blueberry) Oryzopsis asperifolia (rough-leaved ricegrass)
Moss Layer: 95% cover Pleurozium schreberi (red-stemmed feathermoss) Dicranum polysetum (wavy-leaved moss) Cladina spp. (cladina lichens) Peltigera spp. (peltigera lichens) Stereocaulon tomentosum (woolly coral lichen)
SOIL AND SITE
Moisture Regime: 2 (sx) Nutrient Regime: A-B (vp-p) Aspect: level Slope Gradient (%): 0-5
* Slope Position: level * Parent Material: fluvial * Soil Texture: coarse
Coarse Fragments (%): 0-75
DISTRIBUTION: common, especially on the upper coarse- textured (glacio)fluvial terraces of existing or old rivers
184
Pl - Feathermoss - Cladina (SBSmk1/03)
INTERPRETATIONS
Site limitations: - sites within this unit with high coarse fragment content (> 70%) will have significantly reduced soil moisture retention and will be extremely difficult to plant; attempt to regenerate naturally by retaining PI cones.
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
Site preparation: - light scarification for seedbed preparation or summer logging with no site preparation.
Species choice: - Pl
Vegetation potential: - low
Reforestation: - attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant Pl
without site preparation.
Concerns: - full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (i.e. lop and scatter).
- site and soil conditions of this unit result in drought hazard for a significant portion of the growing season; natural regeneration is generally more adapted to surviving these conditions, especially during establishment.
185
SxwFd - Knight’s plume
Vaccinium
membranaceum
Chimaphila umbellata
Pleurozium schreberi
VEGETATION
Tree Layer: 55% cover Douglas-fir, lodgepole pine, hybrid white spruce
Shrub Layer: 35% cover Vaccinium membranaceum (black huckleberry) Spiraea betulifolia (birch-leaved spirea) Rosa acicularis (prickly rose) Viburnum edule (highbush-cranberry) Amelanchier alnifolia (saskatoon) subalpine fir hybrid white spruce
Herb Layer: 15% cover Cornus canadensis (bunchberry) Orthilia secunda (one-sided wintergreen) Goodyera oblongifolia (rattlesnake-plantain) Goodyera repens (dwarf rattlesnake orchid) Smilacina racemosa (false Solomon’s-seal) Chimaphila umbellata (prince’s pine) Arnica cordifolia (heart-leaved arnica) Linnaea borealis (twinflower)
Moss Layer: 90% cover Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) Hylocomium splendens (step moss) Rhytidiadelphus triquetrus (electrified cat’s-tail moss)
SOIL AND SITE
Moisture Regime: 2-3 (sx-sm) Nutrient Regime: B-C (p-m)
* Aspect:
* Slope Position:
south to west if midslope
mid to crest Slope Gradient (%): 2-55
Parent Material: variable Soil Texture: variable, rarely moderately
Coarse Fragments (%): 15-60 fine or fine
COMMENTS: usually represented by older stands; may be old Douglas-fir stumps in younger stands
DISTRIBUTION: uncommon, and localized within the range of Douglas-fir
186
SxwFd - Knight’s plume (SBSmk1/04)
INTERPRETATIONS
Site limitations: - sites within this unit with high coarse fragment content (> 70%) will have significantly reduced soil moisture retention and will be extremely difficult to plant; attempt to regenerate naturally by retaining Pl cones and/or leaving Fd seed-trees on site.
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
Site preparation: - light scarification for seedbed preparation or summer logging with no site preparation.
Species choice: - Fd, Pl, (Sx, Bl)
Vegetation potential: - low
Reforestation: - if Fd stems are present, conduct a stand evaluation to assess if a partial cutting system is feasible.
- if abundant Fd advance regeneration is present, attempt to log in a manner that protects this regeneration.
- natural Pl and Fd regeneration should be promoted by light scarification or spot screefing.
- fill-planting may be required to meet stocking requirements.
Concerns: - full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (i.e. lop and scatter).
- site and soil conditions of this unit result in drought hazard for a significant portion of the growing season; natural regeneration is generally more adapted to surviving these conditions, especially during establishment.
- sites within this unit are vulnerable to nutrient deficiency if forest floors are reduced; site preparation methods that reduce forest floor thickness, such as slashburning or brushblading, must be avoided.
187
SxwFd - Toad-flax
Vaccinium
membranaceum
Oryzopsis asperifolia
Pleurozium schreberi
VEGETATION
Tree Layer: 45% cover lodgepole pine, hybrid white spruce, [Douglas-fir]
Shrub Layer: 30% cover Vaccinium membranaceum (black huckleberry) Spiraea betulifolia (birch-leaved spirea) Rosa acicularis (prickly rose) Lonicera involucrata (black twinberry) Amelanchier alnifolia (saskatoon) Rubus parviflorus (thimbleberry) subalpine fir
Herb Layer: 30% cover Cornus canadensis (bunchberrry) Clintonia uniflora (queen’s cup) Linnaea borealis (twinflower) Goodyera oblongifolia (rattlesnake-plantain) Oryzopsis asperifolia (rough-leaved ricegrass) Epilobium angustifolium (fireweed)
Moss Layer: 95% cover Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) Dicranum polysetum (wavy-leaved moss) Peltigera aphthosa (freckle lichen) Hylocomium splendens (step moss) Rhytidiadelphus triquetrus (electrified cat’s-tail moss)
SOIL AND SITE
Moisture Regime: 3-4 (sm-m) Nutrient Regime: B-C (p-m) Aspect: south to west or flat
mid to upper rarely level
medium to coarse
Slope Gradient (%): 0-45 * Slope Position:
* Soil Texture: Parent Material: morainal or (glacio)fluvial
Coarse Fragments (%): 0-30
COMMENTS: may be difficult to differentiate from Sxw - Huckleberry - Highbush-cranberry (SBSmk1/01)
DISTRIBUTION: common, widespread, and often large
188
SxwFd - Toad-flax (SBSmk1/05)
INTERPRETATIONS
Site limitations: - see Concerns.
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
Site preparation: - light scarification for seed bed preparation or summer logging with no site preparation.
Species choice:
Vegetation potential: - low
Reforestation:
- Pl, Sx, Fd, (Bl)
- attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant Pl or Fd
without site preparation. - within this unit, Fd should generally be planted only
on south facing, coarse-textured sites within its natural range.
Concerns: - full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (i.e. lop and scatter).
- sites within this unit with shallow and/or coarse- textured soils are vulnerable to nutrient deficiency if forest floors are reduced; site preparation methods such as slashburning or brushblading, that reduce forest floor thickness, must be avoided.
- site and soil conditions of this unit result in drought hazard for a significant portion of the growing season; leaving a shelterwood overstory can reduce the severity of the drought hazard.
- spruce weevil constitutes a moderate hazard south of Weedon Lake and east of Great Beaver Lake; consider modifying brush treatments in localized areas with > 5% current attack.
- mountain pine beetle may cause mortality in large diameter lodgepo!e pine stands of age class > 7.
189
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Sb - Huckleberry - Spirea
Vaccinium membranaceum
Vaccinium caespitosum
Geocaulon lividum
VEGETATION
Tree Layer: 30% cover lodgepole pine, black spruce, hybrid white spruce
Shrub Layer: 25% cover Vaccinium membranaceum (black huckleberry) Lonicera involucrata (black twinberry) Rosa acicularis (prickly rose) Spiraea betulifolia (birch-leaved spirea) Amelanchier alnifolia (saskatoon) Sorbus scopulina (western mountain-ash) subalpine fir
Herb Layer: 35% cover Cornus canadensis (bunchberry) Vaccinium caespitosum (dwarf blueberry) Geocaulon lividum (bastard toad-flax) Linnaea borealis (twinflower) Epilobium angustifolium (fireweed) Achillea millefolium (yarrow) Petasites frigidus var. palmatus (palmate coltsfoot) Oryzopsis asperifolia (rough-leaved ricegrass) Orthilia secunda (one-sided wintergreen)
Moss Layer: 95% cover Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) Hylocomium splendens (step moss)
SOIL AND SITE
Moisture Regime: 3-6 (sm-hg) Nutrient Regime: A-B (vp-p)
* Aspect: northerly or flat * Slope Gradient (%): * Slope Position:
usually < 10 lower or level
lacustrine Parent Material: morainal, glaciofluvial or
Soil Texture: variable Coarse Fragments (%): 0-70 Seepage Water: may be present
COMMENTS: often associated with compact soils; water table often near surface, especially in spring
DISTRIBUTION: common, especially on level compact till
190
Sb - Huckleberry - Spirea (SBSmk1/06)
INTERPRETATIONS
Site limitations: - compact soil layers and/or low aeration porosity associated with fine-textured soils will reduce rooting depth and decrease productivity over a rotation; regenerate naturally whenever possible.
- soils are saturated in the spring, but may experience drought in summer, both resulting in poor root development; the poor productivity resulting from these limitations should dictate a limited intensive silvicultural investment.
- sites within this unit with medium- to fine-textured lacustrine soils often have poor soil structure, leading to poor root growth; plant stock which will achieve better lateral root development (eg. Cu- treated), prescribe natural regeneration, or protect advance regeneration.
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
Site preparation: - see Section 5.2
Species choice: - Pl, (SX, Sb)
Vegetation potential: - low
Reforestation: - attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant Pl. - Sx and Sb will generally be less productive on these
sites.
Concerns: - full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (i.e. lop and scatter).
- site conditions may lead to frost damage of regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost resistant species (eg., Pl) are advised.
- mountain pine beetle may cause mortality in large diameter lodgepole pine stands of age class > 7.
191
Sxw - Oak fern
Viburnum edule
Gymnocarpium dryopteris
Ptilium crista-castrensis
VEGETATION
Tree Layer: 35% cover hybrid white spruce, subalpine fir
Shrub Layer: 30% cover Ribes lacustre (black gooseberry) Viburnum edule (highbush-cranberry) Lonicera involucrata (black twinberry) Vaccinium membranaceum (black huckleberry) Spiraea betulifolia (birch-leaved spirea) Oplopanax horridus (devil’s club) subalpine fir
Herb Layer: 40% cover Gymnocarpium dryopteris (oak fern) Streptopus amplexifolius (clasping twistedstalk) Cornus canadensis (bunchberry) Orthilia secunda (one-sided wintergreen) Tiarella unifoliata (one-leaved foamflower) Tiarella trifoliata (three-leaved foamflower) Smilacina racemosa (false Solomon’s-seal) Clintonia uniflora (queen’s cup)
Moss Layer: 95% cover Ptilium crista-castrensis (knight’s plume) Pleurozium schreberi (red-stemmed feathermoss) Hylocomium splendens (step moss) Rhytidiadelphus triquetrus (electrified cat’s-tail moss) [Mnium spp.] (leafy mosses)
SOIL AND SITE
Moisture Regime: 5 (shg) Nutrient Regime: B-D (p-r) Slope Gradient (%): 0-50
* Slope Position: usually middle to toe Parent Material: variable Soil Texture: variable Coarse Fragments (%): 0-55
* Seepage Water: may be present below 50 cm.
COMMENTS: nutrient-rich sites may have patchy cover of oak fern
DISTRIBUTION: common, and found in association with SBSmk1/01 and SBSmk1/08
192
Sxw - Oak fern (SBSmk1/07)
INTERPRETATIONS
Site limitations: - sites within this unit with medium- to fine-textured lacustrine soils often have poor soil structure, leading to poor root growth; plant stock which will achieve better lateral root development (eg. Cu- treated), prescribe natural regeneration, or protect advance regeneration.
Silviculture system:
Site preparation:
- see Section 5.1
- see Section 5.2
Species choice: - SX, Pl, Fd, [Bl]
Vegetation potential:
Reforestation:
- moderate (black twinberry, thimbleberry, fireweed)
- if vigorous advanced Fd or Sx regeneration is present it should be preserved when feasible.
- plant sturdy stock as soon after harvesting as possible.
- young Bl regeneration (< 3m tall) may be susceptible to heavy browsing by moose.
- Fd should be restricted to warm aspects on coarse- textured soils within the natural range of Fd.
- help maintain stand diversity on sites to be planted with Pl by mapping aspen patches prior to harvest and planting these areas to spruce.
Concerns: - sites within this unit with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations or dry soil conditions.
- site conditions may lead to frost damage of regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost resistant species (eg., Pl) are advised.
- spruce weevil constitutes a moderate hazard south of Weedon Lake and east of Great Beaver Lake; consider modifying brush treatments in localized areas with > 5% current attack.
- tomentosus root rot may cause moderate to severe problems in mature spruce dominated stands.
- black army cutworm can cause severe defoliation on south facing slopes that have been slashburned.
- Warren's root collar weevil can cause mortality in young stands, especially where duff layers are thick.
193
Sxw - Devil’s club
Oplopanax horridus
Gymnocarpium dryopteris
Athyrium filix-femina
VEGETATION
Tree Layer: 45% cover hybrid white spruce, subalpine fir
Shrub Layer: 55% cover Oplopanax horridus (devil’s club) Ribes lacustre (black gooseberry) Viburnum edule (highbush-cranberry) Lonicera involucrata (black twinberry) Rubus parviflorus (thimbleberry) Sorbus scopulina (western mountain-ash) subalpine fir hybrid white spruce
Herb Layer: 55% cover Gymnocarpium dryopteris (oak fern) Athyrium filix-femina (lady fern) Tiarella unifoliata (one-leaved foamflower) Tiarella trifoliata (three-leaved foamflower) Cornus canadensis (bunchberry) Smilacina racemosa (false Solomon’s-seal) Aralia nudicaulis (wild sarsaparilla) Mitella nuda (common mitrewort)
Moss Layer: 40% cover Mnium spp. (leafy mosses) Ptilium crista-castrensis (knight’s plume) Pleurozium schreberi (red-stemmed feathermoss) Rhytidiadelphus triquetrus (electrified cat’s-tail moss)
SOIL AND SITE
Moisture Regime: 5-6 (Shg-hg) Nutrient Regime: C-E (m-vr) Aspect: commonly northwesterly to
easterly
lower to level * Slope Gradient (%): 2-16 * Slope Position:
Parent Material: variable Soil Texture: generally moderately coarse
Coarse Fragments (%): 4-20 to moderately fine
may be present at depths greater than 30 cm
* Seepage Water:
DISTRIBUTION: common, but limited to stream edges or flats receiving seepage
194
Sxw - Devil’s club (SBSmk1/08)
INTERPRETATIONS
Site limitations: - sites with saturated soils are poorly aerated, which slows root development; plant seedlings on naturally or artificially raised microsites.
- sites with medium- to fine-textured lacustrine soils often have poor soil structure, leading to poor root growth; plant stock which achieves better lateral root development (eg. Cu-treated), prescribe natural regeneration, or protect advance regeneration.
- see Section 5.1
- see Section 5.2
- [Pl], Sx, [Bl]
- high (black twinberry, thimbleberry, fireweed)
- preserve vigorous advanced Sx regeneration. - plant sturdy stock immediately after harvesting. - young Bl regeneration (< 3m tall) may be susceptible
Silviculture system:
Site preparation:
Species choice:
Vegetation potential:
Reforestation:
to heavy browsing by moose.
Concerns: - site conditions may lead to frost damage of regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost resistant species (eg., Pl) are advised.
- sites with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations or dry soil conditions.
- sites within this unit with silty soils are susceptible to frost-heaving; bare root stock will likely resist frost-heaving better than plug stock.
- sites within this unit with thick organic horizons and/or shallow (< 30 cm) effective rooting depth have increased windthrow hazard; block layouts must have wind-firm boundaries, or a wide buffer of standing timber must be left around such sites.
- spruce weevil constitutes a moderate hazard south of Weedon Lake and east of Great Beaver Lake; consider modifying brush treatments in localized areas with > 5% current attack.
- tomentosus root rot may cause moderate to severe damage in mature spruce dominated stands.
- mountain pine beetle may cause mortality in large diameter lodgepole pine stands of age class > 7.
- black army cutworm can cause severe defoliation on south facing slopes which have been slashburned.
195
Sxw - Horsetail: Fluvial phase
Lonicera involucrata
Cornus stolonifera
Equisetum arvense
VEGETATION
Tree Layer: 40% cover hybrid white spruce, [black cottonwood, lodgepole pine, subalpine fir]
Shrub Layer: 35% cover Lonicera involucrata (black twinberry) Cornus stolonifera (red-osier dogwood) Rosa acicularis (prickly rose) Viburnum edule (highbush-cranberry) Ribes lacustre (black gooseberry) 1 Ribes triste (red swamp currant) hybrid white spruce
1 Herb Layer: 60% cover Equisetum pratense (meadow horsetail) Equisetum arvense (common horsetail) Rubus pubescens (trailing raspberry) Galium triflorum (sweet-scented bedstraw) Cornus canadensis (bunchberry) Mitella nuda (common mitrewort) Linnaea borealis (twinflower) Osmorhiza chilensis (mountain sweet-cicely)
Moss Layer: 55% cover Ptilium crista-castrensis (knight's plume) Mnium spp. (leafy mosses) Pleurozium schreberi (red-stemmed feathermoss) Hylocomium splendens (step moss) Rhytidiadelphus triquetrus (electrified cat's-tail moss)
SOIL AND SITE
Moisture Regime: 6 (hg) Nutrient Regime: C-D (m-r) Aspect: flat or northerly
* Slope Gradient (%): 0-8 * Slope Position: usually level * Parent Material: usually fluvial, rarely sloping
morainal
1-65, usually 10 Soil Texture: medium to coarse Humus Thickness (cm): Coarse Fragments (%): 0-80
* Seepage Water: usually present at depths greater than 30 cm.
DISTRIBUTION: common but small in area, and generally associated with edges of waterways
196
Sxw - Horsetail: Fluvial phase (SBSmk1/09a)
INTERPRETATIONS
Site limitations: - very difficult sites to manage; serious consideration should be given to managing these sites as wildlife corridors.
- sites with saturated soils are poorly aerated, which slows root development; plant seedlings on naturally or artificially raised microsites.
Silviculture system:
Site preparation:
- see Section 5.1
- see Section 5.2 - creating an excessive number of mounds (eg.,
>300/ha) should be avoided, especially on sites within this unit with a water table < 30 cm from the surface.
Species choice:
Vegetation potential:
Reforestation:
- Sx , [Pl, Bl]
- high (black twinberry, fireweed, bluejoint)
- advance regeneration should be preserved. - supplement advance regeneration by planting sturdy
stock in groups, using available raised microsites. - young Bl regeneration (< 3 m tall) may be susceptible
to heavy browsing by moose.
Concerns: - site conditions may lead to frost damage of regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) are advised.
- sites with thick organic horizons (> 10 cm) have extreme windthrow hazard; block layouts must have windfirm boundaries, or a wide buffer of standing timber must be left around such sites.
- water table will likely rise above the ground surface in the spring, causing seedling mortality.
- these units represent important wildlife habitat, so discuss prescription with fish and wildlife personnel.
- this unit is critical to the control of runoff stream flow.
- spruce weevil constitutes a moderate hazard south of Weedon Lake and east of Great Beaver Lake; consider modifying brush treatments in localized areas with > 5% current attack.
- tomentosus root rot may cause moderate to severe problems in mature spruce-dominated stands.
- Warren's root collar weevil can cause mortality in young stands, especially where duff layers are thick.
- black army cutworm can cause severe defoliation on south-facing slopes that have been slashburned.
197
Sxw - Horsetail: Organic phase
Lonicera involucrata
Equisetum arvense
Sphagnum capillaceum
VEGETATION
Tree Layer: 35% cover hybrid white spruce, [black spruce]
Shrub Layer: 35% cover Lonicera involucrata (black twinberry) Ribes lacustre (black gooseberry) Rosa acicularis (prickly rose) Alnus tenuifolia (mountain alder) Cornus stolonifera (red-osier dogwood) Viburnum edule (highbush-cranberry) subalpine fir
Herb Layer: 70% cover Equisetum arvense (common horsetail) Equisetum sylvaticum (wood horsetail) Cornus canadensis (bunchberry) Gymnocarpium dryopteris (oak fern) Mitella nuda (common mitrewort) Streptopus amplexifolius (clasping twistedstalk) Linnaea borealis (twinflower) Orthilia secunda (one-sided wintergreen) Galium triflorum (sweet-scented bedstraw) Cinna latifolia (nodding wood-reed) Rubus pubescens (trailing raspberry)
Moss Layer: 95% cover Hylocomium splendens (step moss) Rhytidiadelphus triquetrus (electrified cat’s-tail moss) Ptilium crista-castrensis (knight’s plume) Mnium spp. (leafy mosses) Sphagnum capillaceum (common red sphagnum)
SOIL AND SITE
Moisture Regime: 6-7 (hg-Shd) Nutrient Regime: C-D (m-r)
* Slope Gradient (%): 0-4 * Slope Position: level
Parent Material: organic, morainal, and lacustrine organic in rooting zone
always present within 50 cm
* Soil Texture:
* Water Table: Coarse Fragments (%): usually zero
DISTRIBUTION: uncommon and small, usually adjacent to bogs
198
Sxw - Horsetail: Organic phase (SBSmk1/09b)
INTERPRETATIONS
Site limitations: - site and soil conditions of this unit result in marginal forest productivity; serious consideration should be given to excluding logging from this unit.
- sites with saturated soils are poorly aerated, which slows root development; plant seedlings on naturally or artificially raised microsites.
- sites with thick organic horizons (> 10 cm) have reduced spring soil temperatures, slowing root development; reduce organic horizon thickness during site preparation.
Silviculture system:
Site preparation:
- see Section 5.1
- see Section 5.2 - creating an excessive number of mounds (eg.,
>300/ha) should be avoided, especially on sites within this unit with a water table < 30 cm from the surface.
Species choice:
Vegetation potential:
Reforestation:
- Sx, [Pl, Bl]
- high (black twinberry, fireweed, bluejoint)
- advance regenerations should be preserved. - supplement advance regeneration by planting sturdy
stock in groups, using available raised microsites. - young Bl regeneration (< 3 m tall) may be susceptible
to heavy browsing by moose.
Concerns: - site conditions may lead to frost damage of regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) are advised.
- sites within this unit have extreme windthrow hazard; block layouts must have windfirm boundaries, or a wide buffer of standing timber must be left around such sites.
- water table will likely rise above the ground surface in the spring, causing seedling mortality.
- these units represent important wildlife habitat, so discuss prescription with fish and wildlife personnel.
- spruce weevil constitutes a moderate hazard south of Weedon Lake and east of Great Beaver Lake; consider modifying brush treatments in localized areas with > 5% current attack.
- tomentosus root rot may cause moderate to severe problems in mature spruce-dominated stands.
- black army cutworm can cause severe defoliation on south-facing slopes that have been slashburned.
199
Sb - Scrub birch - Sedge
Ledum groenlandicum
Carex spp.
Sphagnum capillaceum
VEGETATION
Tree Layer: 10% cover black spruce
Shrub Layer: 50% cover Ledum groenlandicum (Labrador tea) Betula glandulosa (scrub birch) Salix spp. (willows) Alnus tenuifolia (mountain alder) Lonicera involucrata (black twinberry) black spruce
Carex spp. (sedges) Equisetum arvense (common horsetail) Equisetum fluviatile (swamp horsetail) Calamagrostis canadensis (bluejoint) Oxycoccus oxycoccos (bog cranberry) Pyrola asarifolia (pink wintergreen) Orthilia secunda (one-sided wintergreen) Platanthera dilatata (white bog-orchid) Potentilla palustris (marsh cinquefoil) Gaultheria hispidula (creeping-snowberry) Cinna latifolia (nodding wood-reed)
Sphagnum spp. (sphagnums) Pleurozium schreberi (red-stemmed feathermoss) Hylocomium splendens (step moss) Ptilium crista-castrensis (knight’s plume) Aulacomnium palustre (glow moss) Tomenthypnum nitens Mnium spp. (leafy mosses)
Herb Layer: 80% cover
Moss Layer: 75% cover
(golden fuzzy fen moss)
SOIL AND SITE
Moisture Regime: 7 (shd) Nutrient Regime : B-D (p-r)
* Slope Gradient (%): 0 * Slope Position: * Parent Material: organic
Soil Texture: organic * Water Table:
level or depression
within 50 cm. of surface
DISTRIBUTION: common, but small in size and associated with organic soils
200
Sb - Scrub birch - Sedge (SBSmk1/10)
INTERPRETATIONS
Site limitations: - site and soil conditions of this unit result in marginal forest productivity; serious consideration should be given to excluding logging from this unit.
Silviculture system: - avoid logging
201
4.7 Moist Cold Sub-Boreal Pine - Spruce 18
Location The SBPSmc occurs in the western portions of the guide area, generally at elevations between 900 and 1200 m. In the guide area, it is bordered by the SBSmc3 to the east and SBSdk to the north (Figure 1).
Elevation range 850 - 1300 m
Climate The climate, due to its position on a high plateau on the lee side of the Coast Mountains, is relatively dry and cold. The SBPSmc has the driest climate of the biogeoclimatic units described. The summers are dry and short, limiting forest productivity in this unit. It has the shortest growing season of any of the units described, with the exception of the ESSFmv1.
Soils, Geology, and Landforms Bedrock in this subzone is predominantly volcanic (andesite and basalt) of Tertiary age. Parent materials are dominantly morainal, with gravelly loam textures. The associated soils are Gray Luvisols, including Brunisolic Gray Luvisols. Dystric Brunisols have formed on coarser morainal and glaciofluvial materials with gravelly loamy sand and sand textures.
Distinguishing the SBPSmc from adjoining biogeoclimatic units SBSdk has: • generally better developed shrub and herb layers, especially on mesic sites; • trembling aspen in the canopy; and • purple peavine but less kinnikinnick in the herb layer, especially on mesic
SBSmc3 has: • subalpine fir in the canopy; and • more trailing raspberry but less kinnikinnick in the herb layer, especially on
mesic sites. ESSFmv1 has: • subalpine fir in the canopy; • white-flowered rhododendron but no prickly rose in shrub layer; and • heart-leaved arnica but no kinnikinnick in the herb layer, especially on
sites.
mesic sites.
Forests Recurrent fires have ensured that climax forests are dominated by lodgepole pine. Hybrid white spruce occurs on moisture-receiving sites. Black spruce occurs in wetlands and also on upland sites on poor soils in combination with lodgepole pine. Black cottonwood occurs along streams and rivers, and is often associated with hybrid white spruce. Forest productivity is low, being limited by the dry, short growing season.
18 formerly SBSa
202
Wildlife Dry pine-dominated sites within this unit with abundant terrestrial lichen provide critical winter habitat for woodland caribou Older spruce and pine forests provide arboreal lichen that can be important for the caribou, especially in winters with high snowfall. Shrub-dominated wetlands below 1000 m elevation provide important winter habitat for moose. This wetland habitat also supports furbearers such as beaver, muskrat, mink, and otter. Sub-boreal coniferous forests are used by moose, mule deer, grizzly bear, black bear, white- tailed deer, spruce grouse, and furbearers, such as wolverine, marten and red squirrel.
203
Soil Nutrient Regime Very Poor Poor Medium Rich Very Rich
A B C D E
Very Xeric 0
Xeric 1
Subxeric 2
Submesic 3
Mesic 4
Subhygric 5
Hygric 6
Subhydric 7
01 Pl- Feathermoss - Cladina 04 Sxw - Scrub birch - 02 Pl- Kinnikinnick - Feathermoss
Cladonia 05 Sxw - Horsetail 03 SbPl - Feathermoss 06 Sxw - Horsetail - Glow moss
07 SbSxw - Scrub birch - Sedge
FIGURE 21. Edatopic grid displaying site units in the SBPSmc subzone.
204
Site Units 02 03 01 04 05 06 07 Trees
Pinus contorta
Picea mariana Picea glauca
Shrubs Shepherdia canadensis
Vaccinium membranaceum Ledum groenlandicum Lonicera involuctrata
Salix spp. (glauca, barclayi)
Arctostaphylos uva-ursi
Equisetum arvense Equisetum sylvaticum
Carex spp.
Empetrum nigrum
Cladina spp.
Hylocomium splendens Mnium spp.
Aulacomnium palustre Tomenthypnum nitens
Sphagnum spp.
Herbs and Dwarf Shrubs
Calamagrostis canadensis
Mosses and Lichens
lodgepole pine
white spruce
black spruce
soopolallie
black huckleberry
Labrador tea
black twinberry
willows
kinnikinnick
bluejoint
common horsetail
wood horsetail
sedges
crowberry
cladina lichens
step moss
leafy moss
glow moss
golden fuzzy fen moss
sphagnums
FIGURE 22. SBPSmc vegetation table. Prominence class:
1 a Black spruce always present; poor tree productivity; Ledum groenlandicum (p.40) 19, Empetrum nigrum (p.79), or Betula glandulosa (p. 39) present.
2a Canopy of stunted black spruce; on wet organic soils; moss layer dominated by Sphagnum spp. (p.312).
SPBSmc07
Lodgepole pine - black spruce or white spruce - black spruce canopy; on mineral soil; moss layer dominated by feathermosses.
3a
2b
Canopy dominated by white spruce or lodgepole pine; generally on imperfectly drained soils adjacent to wetlands; Aulacomnium palustre (p.311) present.
SBPSmc/04
Canopy dominated by lodgepole pine; generally on moderately well drained soils on upland sites; Aulacomnium palustre absent.
SBPSmc/03
Black spruce generally absent or low cover; moderately productive forests; Ledum groenlandicum, Empetrum nigrum, and Betula glandulosa generally absent.
4a
3b
1b
Canopy dominated by white spruce; seepage water often present; Equisetum spp. (p.280) present; minor lichen cover if present.
5a Shrub layer moderately developed; on a variety of parent materials but usually thick organic layers present; Mnium spp. (p.307) present.
SBPSmc/06
Shrub layer sparse; generally on fluvial terraces with variable humus layer depth; Mnium spp. generally absent.
5b
SBPSmc/05
4b Canopy dominated by lodgepole pine; seepage water absent; Equisetum spp. absent; lichens common.
19 Page numbers refer to the publication Plants of Northern British Columbia (MacKinnon et al. 1992).
206
6a Canopy generally pure lodgepole pine; sparse shrub layer; herb layer sparse and dominated by Arctostaphylos uva-ursi (p.82); moss layer dominated by lichens; generally on coarse-textured glaciofluvial soils.
SBPSmc/02
Canopy pure lodgepole pine or mixed lodgepole pine and white spruce; herb layer better developed and dominated by other species; moss layer comprised of feathermosses and lichens; on medium- to coarse-textured morainal and glaciofluvial soils.
6b
SBPSmc/01
207
Pl - Feathermoss - Cladina
Shepherdia canadensis
Arctostaphylos uva-ursi
VEGETATION
Tree Layer: 35% cover lodgepole pine, white spruce
Shrub Layer: 20% cover Shepherdia canadensis (soopolallie) [Rosa acicularis (prickly rose)] [Spiraea betulifolia: (birch-leaved spirea)] [Juniperus communis (common juniper)] white spruce [lodgepole pine]
Cornus canadensis (bunchberry) Arctostaphylos uva-ursi (kinnikinnick) Linnaea borealis (twinflower) Vaccinium caespitosum (dwarf blueberry) [Epilobium angustifolium (fireweed)] [Calamagrostis canadensis (bluejoint)]
Herb Layer: 20% cover
Moss Layer: 75% cover Pleurozium schreberi (red-stemmed feathermoss) Peltigera spp. (peltigera lichens) Cladina spp. (cladina lichens) [Hylocomium splendens (step moss)] [Ptilium crista-castrensis (knight’s plume)] [Dicranum spp. (dicranum mosses)]
SOIL AND SITE
Moisture Regime: 3-5 (sm-shg) Nutrient Regime: B-C (p-m)
Slope Position: variable Parent Material: morainal or glaciofluvial Soil Texture: variable Coarse Fragments (%): not available
Slope Gradient (%): 0-65
DISTRIBUTION: very common, widespread, and often large
Pleurozium schreberi
208
Pl- Feathermoss - Cladina (SBPSmc/01)
INTERPRETATIONS
Site limitations: - sites within this unit with thick organic horizons (> 10 cm) have reduced spring soil temperatures, which slows root development; reduce organic horizon thickness during site preparation.
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives.
Site preparation: - light scarification for seedbed preparation or summer logging with no site preparation.
Species choice: - Pl (Sb, Sx)
Vegetation potential: - low
Reforestation: - attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant Pl stock
- Sx and Sb are generally not as productive as Pl. without site preparation.
Concerns: - site conditions may lead to frost damage of regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) is advised.
- sites within this unit with shallow and/or coarse textured soils are vulnerable to nutrient deficiency if forest floors are reduced; site preparation methods that reduce forest floor thickness, such as slashburning or brushblading, must be avoided.
- full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (ie., lop and scatter)
- high windthrow hazard if effective rooting depth < 30
- sites with terrestrial lichen cover are valuable for caribou winter habitat, so prescription should be discussed with wildlife personnel.
cm.
209
Pl- Kinnikinnick - Cladonia
Shepherdia canadensis
Arctostaphylos uva-ursi
VEGETATION
Tree Layer: 20% cover lodgepole pine
Shrub Layer: 40% cover Shepherdia canadensis (soopolallie) Spiraea betulifolia (birch-leaved spirea) lodgepole pine
Herb Layer: 20% cover Arctostaphylos uva-ursi (kinnikinnick) Vaccinium caespitosum (dwarf blueberry) [Oryzopsis spp. (ricegrasses)]
Moss layer: 95% cover Cladina spp. (cladina lichens) Cladonia spp. (cladonia lichens) Peltigera spp. (peltigera lichens) Stereocaulon spp. (coral lichens) [Pleurozium schreberi (red-stemmed feathermoss)]
SOIL AND SITE
Moisture Regime: 1-2 (x-sx) Nutrient Regime: A-B (vp-p) Slope Gradient (%): 0-44
* Slope Position: upper - crest
veneers moderately coarse - coarse
Parent Material: glaciofluvial, or colluvial
Coarse Fragments (%): not available * Soil Texture:
DISTRIBUTION: common, but localized on eskers and other glaciofluvial landforms
Cladonia spp.
210
Pl - Kinnikinnick - Cladonia (SBPSmc/02)
INTERPRETATIONS
Site limitations: - site and soil conditions of this unit result in marginal forest productivity and sites have high value as caribou winter habitat; serious consideration should be given to excluding logging from this unit.
- sites within this unit with high coarse fragment content (> 70%) will have significantly reduced soil moisture retention and will be extremely difficult to plant; attempt to regenerate naturally by retaining Pl cones.
Silviculture system:
Site preparation:
- see Section 5.1
- no site preparation
Species choice: - Pl, (SX, Sb)
Vegetation potential: - low
Reforestation: - attempt to regenerate naturally if potential exists. - i f natural regeneration is not feasible, plant Pl
- Sx and Sb are significantly less productive than Pl on without site preparation.
these sites.
Concerns: - full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (i.e. lop and scatter).
211
SbPl - Feathermoss
Ledum groenlandicum
Empetrum nigrum
Pleurozium schreberi
VEGETATION
Tree Layer: 50% cover lodgepole pine, black spruce
Shrub Layer: 25% cover Ledum groenlandicum (Labrador tea) Vaccinium membranaceum (black huckleberry) [Lonicera involucrata (black twinberry)] [Rosa acicularis (prickly rose)] black spruce
Herb Layer: 20% cover Empetrum nigrum (crowberry) Petasites frigidus var. palmatus (palmate coltsfoot) Cornus canadensis (bunchberry) Linnaea borealis (twinflower) [Lycopodium annotinum (stiff clubmoss)]
Moss Layer: 85% cover Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) Hylocomium splendens (step moss) Peltigera spp. (peltigera lichens) [Cladina spp. (cladina lichens)]
SOIL AND SITE
Moisture Regime: 3-4 (sm-m) Nutrient Regime: A-B (vp-p) Slope Gradient (%): 0-20
* Slope Position: * Aspect: generally northerly
mid or level
Parent Material: morainal blankets with glaciofluvial deposits medium - moderately coarse * Soil Texture:
Coarse fragments (%): not available
DISTRIBUTION: scattered; most common on cool, northerly aspects
212
SbPl - Feathermoss (SBPSmc/03)
INTERPRETATIONS
Site limitations: - compact soil layers and/or low aeration porosity associated with fine-textured soils will reduce rooting depth and decrease productivity over a rotation; regenerate naturally whenever possible.
- soils are saturated in the spring, but may experience drought in summer, both resulting in poor root development; the poor productivity resulting from these limitations should dictate a limited intensive silvicultural investment.
- sites within this unit with thick organic horizons (> 10 cm) have reduced spring soil temperatures, slowing root development; reduce organic horizon thickness during site preparation.
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
Site preparation: - see Section 5.2
Species choice: - Pl, (SX, Sb)
Vegetation potential: - low
Reforestation: - Sx and Sb are significantly less productive than Pl. - attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant Pl.
- full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (i.e. lop and scatter).
- sites within this unit with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations or dry soil conditions.
- possible windthrow hazard if effective rooting depth is < 30 cm.
Concerns:
213
Betula glandulosa
Calamagrostis canadensis
Sxw - Scrub birch - Feathermoss
VEGETATION
Tree Layer: 50% cover lodgepole pine, white spruce, [black spruce]
Shrub Layer: 25% cover Betula glandulosa (scrub birch) [Rosa acicularis (prickly rose)] [Ledum groenlandicum (Labrador tea)]
white spruce [lodgepole pine] [black spruce]
[Salix spp. (willows)]
Herb Layer: 20% cover Calamagrostis canadensis (bluejoint) Linnaea borealis (twinflower) Cornus camdensis (bunchberry) Empetrum nigrum (crowberry)
Moss Layer: 75% cover Pleurozium schreberi (red-stemmed feathermoss) Aulacomnium palustre (glow moss) Peltigera spp. (peltigera lichens) Cladina spp. (cladina lichens) Hylocomium splendens (step moss)
SOIL AND SITE
Moisture Regime: 5-6 (shg-hg) Nutrient Regime: A-B (vp-p) Slope Gradient (%): 2-4
* Slope Position: lower and toe Parent Material: morainal Soil Texture: variable Coarse Fragments (%): not available
* Seepage Water: often present
DISTRIBUTION: common, but generally localized as imperfectly drained fringes around wetlands
Aulacomnium palustre
214
Sxw - Scrub birch - Feathermoss (SBPSmc/04)
INTERPRETATIONS
Site limitations: - site and soil conditions of this unit result in marginal forest productivity; serious consideration should be given to exclude logging from this unit.
- sites within this unit with saturated soils are poorly aerated, which slows root development; plant seedlings on naturally or artificially raised microsites.
(> 10 cm) have reduced spring soil temperatures, slowing root development; reduce organic horizon thickness during site preparation.
- sites within this unit with thick organic horizons
Silviculture system: - see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
Site preparation: - light scarification for seed bed preparation, light burn or disk trench (plant on berm).
Species choice: - Pl, Sb, SX
Vegetation potential: - low
Reforestation: - do not accept advance Bl regeneration. - attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant Pl stock.
- sites within this unit with high water tables, combined with thick organic horizons (> 10 cm), increase the windthrow hazard; block layouts must have wind-firm boundaries, or a wide buffer of standing timber must be left around such sites.
- s i te condi t ions m a y l ead to f r o s t damage o f regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) are advised.
- sites within this unit with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations or dry soil conditions.
- water table may rise after logging, making the site non-productive and increasing rotation age of the stand.
- Warren’s root collar weevil can cause mortality in young stands, especially where duff layers are thick.
Concerns:
215
Sxw - Horsetail
Lonicera involucrata
Calamagrostis canadensis
Equisetum arvense
VEGETATION
Tree Layer: 55% cover white spruce, lodgepole pine
Shrub Layer: 25% cover Lonicera involucrata (black twinberry) Rosa acicularis (prickly rose) [Viburnum edule (highbush-cranberry)] [Alnus tenuifolia (mountain alder)] [Ribes lacustre (black gooseberry)] white spruce
Herb Layer: 40% cover Calamagrostis canadensis (bluejoint) Cornus canadensis (bunchberry) Equisetum arvense (common horsetail) Linnaea borealis (twinflower) Epilobium angustifolium (fireweed) Fragaria virginiana (wild strawberry) [Mitella nuda (common mitrewort)] [Petasites frigidus var. palmatus (palmate coltsfoot)]
Moss Layer: 65% cover Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) Hylocomium splendens (step moss) Peltigera spp. (peltigera lichens) [Timmia austriaca (false-polytrichum)]
SOIL AND SITE
Moisture Regime: 5-6 (shg-hg)
Slope Gradient (%): 2-14 Nutrient Regime: C-E (m-vr)
lower - toe usually fluvial, occasionally lacustrine or glaciofluvial
* Slope Position: * Parent Material.
Soil Texture: variable Coarse Fragments (%): not available
* Seepage Water: often present
DISTRIBUTION: restricted to lower and toe slopes adjacent to streams and rivers
216
Sxw - Horsetail (SBPSmc/05)
INTERPRETATIONS
Site limitations: - sites within this unit with saturated soils are poorly aerated, which slows root development; plant seedlings on naturally or artificially raised microsites.
- see Section 5.1
- see Section 5.2 -creating an excessive number of mounds (eg.,
>300/ha) should be avoided, especially on sites within this unit with a water table < 30 cm from the surface.
Silviculture system:
Site preparation:
Species choice: - Sx, [Pl]
Vegetation potential:
Reforestation:
- high (black twinberry, fireweed, bluejoint)
- advance regeneration should be preserved. - supplement advance regeneration by planting sturdy
stock in groups on available raised microsites.
Concerns: - site conditions may lead to frost damage of regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost resistant species (eg., Pl) are advised.
- sites within this unit with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations or dry soil conditions.
- sites within this unit with thick organic horizons (> 10 cm) have an extreme windthrow hazard; block layouts must have wind-firm boundaries, or a wide buffer of standing timber must be left around such sites.
- these units may represent important wildlife and fish habitat so prescription should be discussed with wildlife personnel.
- sites within this unit with silty soils are susceptible to frost-heaving; bare root stock will likely resist frost-heaving better than plug stock.
- water table will likely rise above the ground surface in the spring causing seedling mortality.
- Warren’s root collar weevil can cause mortality in young stands, especially where duff layers are thick.
217
Sxw - Horsetail - Glowmoss
Lonicera involucrata
Equisetum arvense
Aulacomnium palustre
VEGETATION
Tree Layer: 35% cover white spruce
Shrub Layer: 35% cover Lonicera involucrata (black twinberry) Ribes lacustre (black gooseberry) Ribes hudsonianum (northern black currant) [Alnus tenuifolia (mountain alder)] [Rosa acicularis (prickly rose)] white spruce
Herb Layer: 70% cover Equisetum arvense (common horsetail) Equisetum sylvaticum (wood horsetail) Calamagrostis canadensis (bluejoint) Carex spp. (sedges) Mitella nuda (common mitrewort) Cornus canadensis (bunchberry) Linnaea borealis (twinflower) [Rubus pubescens (trailing raspberry)] [Petasites frigidus var. palmatus (palmate coltsfoot)] [Gymnocarpium dryopteris (oak fern)]
Moss Layer: 75% cover Hylocomium splendens (step moss) Mnium spp. (leafy mosses) Aulacomnium palustre (glowmoss) Pleurozium schreberi (red-stemmed feathermoss) [Sphagnum spp. (sphagnums)] [Brachythecium spp. (brachythecium mosses)]
SOIL AND SITE
Moisture Regime: 6-7 (hg-shd) Nutrient Regime: C-E (m-vr)
* Slope Gradient (%): 2-10 * Slope Position: level and depressions
Parent Material: morainal, fluvial, and organic blankets
* Soil Texture: organic Coarse Fragments (%): not available
* Seepage Water: always present
DISTRIBUTION: uncommon, and generally small
218
Sxw - Horsetail - Glowmoss (SBPSmc/06)
INTERPRETATIONS
Site limitations: - site and soil conditions of this unit result in marginal forest productivity; serious consideration should be given to excluding logging from this unit.
- sites within this unit with saturated soils are poorly aerated, which slows root development; plant seedlings o n naturally or artificially raised microsites.
- see Section 5.1
- see Section 5.2
Silviculture system:
Site preparation:
Species choice: - Sx, [Pl]
Vegetation potential:
Reforestation:
- high (black twinberry, fireweed, bluejoint)
- advance regeneration should be preserved. - supplement advance regeneration by planting sturdy
stock in groups on available raised microsites.
Concerns: - site conditions may lead to frost damage of regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) is advised.
(> 10 cm) have an extreme windthrow hazard; block layouts must have windfirm boundaries, or a wide buffer of standing timber must be left around such sites.
- these units may represent important wildlife habitat, so prescription should be discussed with wildlife personnel.
- water table will likely rise above the ground surface in the spring, causing seedling mortality.
- sites within this unit with thick organic horizons
219
SbSxw - Scrub birch - Sedge
Ledum groenlandicum
Kalmia microphylla
VEGETATION
Tree Layer: 20% cover black spruce
Shrub Layer: 70% cover Ledum groenlandicum (Labrador tea) Betula glandulosa (scrub birch)
black spruce [Salix spp. (willows)]
Herb Layer 25% cover Empetrum nigrum (crowberry) Kalmia microphylla (bog-laurel) Oxycoccus oxycoccos (bog cranberry) Carex aquatilis (water sedge) Gaultheria hispidula (creeping-snowberry)
Sphagnum spp. (sphagnums) Aulocomnium palustre (glow moss) Cladina spp. (cladina lichens) Tomenthypnum nitens
Moss Layer: 100% cover
(golden fuzzy fen moss)
SOIL AND SITE
Moisture Regime: 7 (shd) Nutrient Regime: A-B (vp-p)
* Slope Gradient (%): 0 * Slope Position:
Parent Material: organic * Soil Texture: organic
Coarse Fragments (%): 0
level and depressional
DISTRIBUTION: scattered throughout the landscape, but never covering extensive areas
Sphagnum spp.
220
SbSxw - Scrub birch - Sedge (SBPSmc/07)
INTERPRETATIONS
Site limitations: - site and soil conditions of this unit result in marginal forest productivity; serious consideration should be given to excluding logging from this unit.
Silviculture system: - avoid logging
221
4.8 Nechako Moist Very Cold Engelmann Spruce - Subalpine Fir 20
Location The ESSFmv1 occurs primarily in the western portion of the guide area at higher elevations. It extends from Stuart Lake in the north to the Naglico Hills in the south. It occurs above either the SBSmc3 or SBSmc2.
Elevation range 1150 - 1550 m
Climate The ESSFmv1, being situated at high elevation above a relatively high, cold plateau, is the coldest unit in the guide area. It is intermediate in precipitation, with a high proportion of this falling as snow.
Soils, Geology, and Landforms The upland areas in which this subzone occurs are underlain by more erosion- resistant intrusive and volcanic rocks of predominantly Mesozoic age. Soils consist mostly of Humo-Ferric Podzols, reflecting more intense weathering under the moister conditions at high elevation. Parent materials are predominantly morainal, with textures ranging from gravelly sandy loam to gravelly loam.
Distinguishing the ESSFmv1 from adjoining biogeoclimatic units SBSmc3 has: • more prickly rose, but less white-flowered rhododendron in the shrub layer;
• trailing raspberry, but less five-leaved bramble in the herb layer on mesic
SBSmc2 has: • more prickly rose, but less white-flowered rhododendron in the shrub layer;
and • oak fern and devil’s club on wetter sites.
Forests Climax forests are dominated by hybrid white spruce and subalpine fir. Lodgepole pine dominates on drier sites. Black spruce occurs in wetlands and also on upland sites on poor soils in combination with lodgepole pine. Black cottonwood occurs along streams and rivers and is often associated with hybrid white spruce.
Wildlife Willow and scrub birch subalpine is used until late fall by moose. Pine - fir stands with arboreal lichen are sometimes used during the winter by caribou. Coniferous forests are used by moose, grizzly bear, wolverine, marten, red squirrel, blue grouse, and spruce grouse.
and
and wetter sites
20 formerly ESSFv
222
Soil Nutrient Regime
Very Poor Poor Medium Rich Very Rich
A B C D E
Very Xeric 0
Xeric 1
Subxeric 2
Submesic 3
Mesic 4
Subhygric 5
Hygric 6
Subhydric 7
01 Bl - Rhododendron -
02 Pl - Huckleberry - Cladonia
03 Bl - Huckleberry - Feathermoss
04 Bl - Huckleberry -
05 Bl - Horsetail - Glow moss Feathermoss Gooseberry
FIGURE 23. Edatopic grid displaying site units in the ESSFmv1 variant.
223
Site Units 02 03 01 04 05
Trees Pinus contorta
Abies lasiocarpa Picea engelmannii
Vaccinium membranaceum Rhododendron albiflorum
Ribes lacustre Lonicera involucrata
Linnaea borealis Lycopodium a n notonu m
Rubus pedatus Aster ciliolatus
Veratrum viride Tiarella spp.
Equisetum arvense
Cladina spp.
Pelligera aphthosa
Shrubs
Herbs and Dwarf Shrubs
Lichens
FIGURE 24. ESSFmv1 vegetation table.
lodgepole pine
subalpine fir
Engelmann spruce
black huckleberry
white-flowered rhododendron
black gooseberry
black twinberry
twinflower
stiff clubmoss
five-leaved bramble
fringed aster
Indian hellebore
foamflowers
common horsetail
cladina lichens
freckled lichen
Prominence class:
l a Water table or evidence of a periodic water table (mottles) generally within 50 cm of the ground surface; Lonicera involucrata (p. 48) 21 and Aster ciliolatus (p. 117) present.
2a Water table present within 50 cm of ground surface; often thick organic layers (> 25 cm); Equisetum spp. (p. 280) abundant.
ESSFmv1/05
Water table generally not present within 50 cm of ground surface; organic layer rarely > 25 cm; Equisetum spp. low cover (< 5%) or absent.
ESSFmv1/04
2b
l b Water table or evidence of periodic water table generally not present; Lonicera involucrata and Aster ciliolatus very low cover ( < 1%) or absent.
3a Canopy dominated by lodgepole pine; on coarse-textured soils or shallow soils over bedrock Cladina spp. (p. 334) present and generally abundant (> 5% cover).
ESSFmv1/02
3b Canopy dominated by lodgepole pine, Engelmann spruce, or subalpine fir; soils variable; Cladina spp. low cover (< 5%) or absent.
4a Generally found in upper slope positions; Rubus pedatus (p. 92) very low cover (< 1%) or absent.
ESSFmv1/03
Slope position mid to upper; Rubus pedatus generally present.
ESSFmv1/01
4b
21 Page numbers refer to the publication Plants of Northern British Columbia (MacKinnon et al. 1992).
225
Rhododendron albiflorum
Rubus pedatus
Bl - Rhododendron - Feathermoss
VEGETATION
Tree Layer: 35% cover subalpine fir, Engelmann spruce, (lodgepole pine)
Shrub Layer: 35% cover Vaccinium membranaceum (black huckleberry) Rhododendron albiflorum (white-flowered rhododendron) Alnus crispa ssp. sinuata subalpine fir
Orthilia secunda (one-sided wintergreen) Linnaea borealis (twinflower) Cornus canadensis (bunchberry) Lycopodium annotinum (stiff clubmoss) Rubus pedatus (five-leaved bramble) Arnica cordifolia (heart-leaved arnica)
(Sitka alder)
Herb Layer: 20% cover
Moss Layer: 95% cover Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) Peltigera aphthosa (freckle lichen) Dicranum scoparium (broom moss)
SOIL AND SITE
Moisture Regime: 4 (m) Nutrient Regime: B-D (p-r) Slope Gradient (%): 20 (5-65)
* Slope Position: Parent Material: morainal Soil Texture: Coarse Fragments (%):
generally mid to upper
variable but often medium 42 (25 - 85)
DISTRIBUTION: very common, widespread, and often large
Ptilium crista-castrensis
226
Bl - Rhododendron - Feathermoss (ESSFmv1/01)
INTERPRETATIONS
Site limitations: - sites within this unit with thick organic horizons (> 10 cm) have reduced spring soil temperatures, slowing root development; reduce organic horizon thickness during site preparation.
Silviculture system: - see Section 5.1 - log on firm snowpack if considering use of advance
regeneration. - if using a partial cutting system, patches of mineral
soil should be exposed to promote natural spruce regeneration.
- minimize or align large slash accumulations when logging to help meet site preparation objectives and reduce fire hazard.
Site preparation:
Species choice:
Vegetation potential:
- see Section 5.2
- Bl, Se, [Pl]
- moderate to high (white-flowered rhododendron, fireweed)
Reforestation: - try to preserve advance regeneration if it is abundant and likely to release and form an acceptable stand.
- advance Bl regeneration should only be accepted if it is likely to reach management objective before it is 150 years old.
- use of advance Se and Bl regeneration that can be protected by the snowpack should be considered if it is abundant and well distributed.
- plant in summer with stock which has already set bud.
Concerns: - site conditions may lead to frost damage of regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost resistant species (eg., Pl) are advised:
- heavy snowpack may cause stem deformity, especially on steep slopes.
- i f heavy equipment is used in summer, during or after partial cutting, every attempt should be made to avoid disturbing roots of standing trees.
227
Pl - Huckleberry - Cladonia
Spiraea betulifolia
Juniper communis
Pleurozium schreberi
VEGETATION
Tree Layer: 25% cover lodgepole pine
Shrub Layer: 20% cover Vaccinium membranaceum (black huckleberry) Spiraea betulifolia (birch-leaved spirea) Alnus crispa ssp. sinuata Juniperus communis (common juniper) lodgepole pine subalpine fir
(Sitka alder)
Herb Layer: 15% cover Linnaea borealis (twinflower) Arnica cordifolia (heart-leaved arnica) Orthilia secunda (one-sided wintergreen) Calamagrostis canadensis (bluejoint) Vaccinium caespitosum (dwarf blueberry)
Moss Layer: 85% cover Pleurozium schreberi (red-stemmed feathermoss) Peltigera aphthosa (freckle lichen) Polytrichum juniperinum (juniper haircap moss) Cladina arbuscula Stereocaulon tomentosum (woolly coral lichen)
SOIL AND SITE
Moisture Regime: 1-2 (x-sx) Nutrient Regime: A-B (vp-p) Slope Gradient (%): 15 (5-25)
* Slope Position: upper or crest * Parent Material: glaciofluvial or morainal
veneer over rock * Soil Texture: generally coarse
Coarse Fragments (%): 30 (15-50)
DISTRIBUTION: uncommon, and small in size
228
Pl - Huckleberry - Cladonia (ESSFmv1/02)
INTERPRETATIONS
Site limitations: - site and soil conditions of this unit result in marginal forest productivity; serious consideration should be given to excluding logging from this unit.
- sites within this unit with high coarse fragment content (> 70%) will have significantly reduced soil moisture retention and will be extremely difficult to plant; attempt to regenerate naturally by retaining Pl cones or retain advance regeneration.
- see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
Silviculture system:
Site preparation: - light scarification for seedbed preparation or summer logging with no site preparation
Species choice: - Pl, (Bl)
Vegetation potential: - low
Reforestation: - attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant Pl.
- heavy snowpack may cause stem deformity, especially on steep slopes.
- full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (i.e. lop and scatter).
Concerns:
229
Vaccinium membranaceum
Cornus canadensis
Peltigera aphthosa
Bl- Huckleberry - Feathermoss
VEGETATION
Tree Layer: 35% cover lodgepole pine, [Engelmann spruce, subalpine fir]
Shrub Layer: 30% cover Vaccinium membranaceum (black huckleberry) Rhododendron albiflorum (white-flowered rhododendron) subalpine fir
Cornus canadensis (bunchberry) Orthilia secunda (one-sided wintergreen) Linnaea borealis (twinflower) Arnica cordifolia (heart-leaved arnica) Epilobium angustifolium (fireweed) Lycopodium annotinum (stiff clubmoss)
Herb Layer: 15% cover
Moss Layer: 95% cover Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) Peltigera aphthosa (freckle lichen) Polytrichum juniperinum (juniper haircap moss) Hylocomium splendens (step moss)
SOIL AND SITE
Moisture Regime: 3 (sm) Nutrient Regime: B-C (p-m) Slope Gradient (%): 21 (0 - 50)
* Slope Position: * Parent Material:
* Soil texture:
upper - (mid) or level morainal veneer over rock or glaciofluvial coarse - medium 30 (12 - 47) Coarse Fragments (%):
DISTRIBUTION: common, and widespread
230
Bl - Huckleberry - Feathermoss (ESSFmv1/03)
INTERPRETATIONS
Site limitations: - sites within this unit with high coarse fragment content (> 70%) will have significantly reduced soil moisture retention and will be extremely difficult to plant; attempt to regenerate naturally by retaining Pl cones or retain advance regeneration.
- see Section 5.1 - minimize or align large slash accumulations when
logging to help meet site preparation objectives and reduce fire hazard.
Silviculture system:
Site preparation: - drag scarify; mix humus with mineral or light broadcast burn.
Species choice:
Vegetation potential: - low
Reforestation:
- Bl, Se, Pl
- attempt to regenerate naturally if potential exists. - if natural regeneration is not feasible, plant mixtures
of Pl, Se, and Bl.
Concerns: - sites within this unit with shallow and/or coarse- textured soils are vulnerable to nutrient deficiency if forest floors are reduced; site preparation methods that reduce forest floor thickness, such as slashburning or brushblading, must be avoided.
- full tree harvesting will lead to nutrient depletion and seriously reduce cones; woody debris and cones should be distributed across these sites (i.e. lop and scatter).
231
Bl- Huckleberry - Gooseberry
Ribes lacustre
Aster ciliolatus
5 mm
Pyrola asarifolia
VEGETATION
Tree Layer: 40% cover Engelmann spruce, lodgepole pine, [subalpine fir]
Shrub Layer: 25% cover Vaccinium membranaceum (black huckleberry) Ribes lacustre (black gooseberry) Lonicera involucrata (black twinberry) Sorbus scopulina (western mountain-ash) subalpine fir
Herb Layer: 25% cover Linnaea borealis (twinflower) Aster ciliolatus (fringed aster) Amica cordifolia (heart-leaved arnica) Pyrola asarifolia (rosy wintergreen) Orthilia secunda (one-sided wintergreen) Petasites frigidus var. palmatus (palmate coltsfoot) Osmorhiza chilensis (mountain sweet-cicely) Pyrola chlorantha (green wintergreen) Rubus pedatus (five-leaved bramble) Veratrum viride (Indian hellebore) Cornus canadensis (bunchberry) Tiarella trifoliata (three-leaved foamflower)
Moss Layer: 95% cover Pleurozium schreberi (red-stemmed feathermoss) Ptilium crista-castrensis (knight’s plume) Dicranum fuscescens (curly heron’s-bill moss) Peltigera aphthosa (freckle lichen)
SOIL AND SITE
Moisture Regime: 5-6 (shg-hg) Nutrient Regime: C-D (m-r)
* Slope Gradient (%): 12 (0-15) * Slope Position:
* Soil Texture:
mid - toe or depression
medium - fine Parent Material: morainal or glaciofluvial
Coarse Fragments (%): 40 (25-65)
DISTRIBUTION: common, but generally not large
232
5 mm
Bl - Huckleberry - Gooseberry (ESSFmv1/04)
INTERPRETATIONS
Site limitations: - sites within this unit with thick organic horizons (> 10 cm) have reduced spring soil temperatures, slowing root development; reduce organic horizon thickness during site preparation.
Silviculture system: - see Section 5.1 - log on firm snowpack if considering use of advance
regeneration. - if using a partial cutting system, patches of mineral
soil should be exposed to promote natural spruce regeneration.
- minimize or align large slash accumulations when logging to help meet site preparation objectives and reduce fire hazard.
Site preparation:
Species choice:
Vegetation potential:
- see Section 5.2
- Bl, Se, [Pl]
- moderate to high (white-flowered rhododendron, fireweed)
Reforestation: - try to preserve advance regeneration if it is abundant and likely to release and form an acceptable stand.
- advance Bl regeneration should only be accepted if it is likely to reach management objective before it is 150 years old.
- use of advance Se and Bl regeneration that can be protected by the snowpack should be considered if it is abundant and well distributed.
- plant in summer with stock which has already set bud.
Concerns: - site conditions may lead to frost damage of regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) are advised.
- sites within this unit with fine-textured soils are vulnerable to compaction under wet conditions; restrict traffic to winter operations or dry soil conditions.
- heavy snowpack may cause stem deformity, especially on steep slopes.
- if heavy equipment is used in summer, during or after partial cutting, every attempt should be made to avoid disturbing roots of standing trees.
233
Bl - Horsetail - Glow moss
Lonicera involucrata
Equisetum arvense
VEGETATION
Tree Layer: 30% cover Engelmann spruce
Shrub Layer: 35% cover Lonicera involucrata (black twinberry) Ribes lacustre (black gooseberry)
subalpine fir Salix spp. (willows)
Herb Layer: 90% cover Equisetum arvense (common horsetail) Aster ciliolatus (fringed aster) Tiarella trifoilata (three-leaved foamflower) Rubus pedatus (five-leaved bramble) Calamagrostis canadensis (bluejoint) Mitella nuda (common mitrewort) Valeriana sitchensis (Sitka valerian) Senecio triangularis (arrow-leaved groundsel)
Moss Layer: 95% cover Aulacomnium palustre (glow moss)
Hylocomium splendens (step moss) Pleurozium schreberi (red-stemmed feathermoss)
Drepanocladus fluvitans ( ___ )
SOIL AND SITE
Moisture Regime: 6-7 (hg-shd) Nutrient Regime: C-D (m-r)
* Slope Gradient (%): 2 * Slope Position: level or depression
Parent Material: organic or fluvial Soil Texture: variable Coarse Fragments (%): 15
* Seepage Water: generally present
DISTRIBUTION: uncommon, and small in size; associated with areas of poor soil moisture drainage
Aulacomnium palustre
234
Bl - Horsetail - Glow moss (ESSFmv1/05)
INTERPRETATIONS
Site limitations: - sites within this unit with saturated soils are poorly aerated, which slows root development; plant seedlings on naturally or artificially raised microsites.
(> 10 cm) have reduced spring soil temperatures, slowing root development; reduce organic horizon thickness during site preparation.
- very difficult sites to manage; serious consideration should be given to managing these sites as wildlife corridors.
- sites within this unit with thick organic horizons
Silviculture system:
Site preparation:
- see Section 5.1
- see Section 5.2 - creating an excessive number of mounds (eg.,
>300/ha) should be avoided, especially on sites within this unit with a water table < 30 cm from the surface.
Species choice:
Vegetation potential:
Reforestation:
- Se, Bl, [Pl]
- high (black twinberry, fireweed, bluejoint)
- plant large planting stock on raised microsites. - plant stock in groups, using available raised
microsites, rather than evenly across the site. - young Bl regeneration (< 3 m tall) may be susceptible
to heavy browsing by moose. - plant in summer with stock that has already set bud.
Concerns: - site conditions may lead to frost damage of regeneration, especially in any naturally occurring or artificially created depression; leaving a partial canopy and/or choosing a frost-resistant species (eg., Pl) are advised.
- sites within this unit with high water tables, combined with thick organic horizons (> 10 cm), increase the windthrow hazard; block layouts must have windfirm boundaries, or a wide buffer of standing timber must be left around such sites.
- water table will likely rise above the ground surface in the spring, causing seedling mortality.
- these units represent important wildlife habitat, so prescription should be discussed with fish and wildlife personnel.
- this unit is critical to the control of runoff stream flow.
235
5 INDIRECT AND GENERAL INTERPRETATIONS
This section contains general interpretations for identification of silvicultural systems options (Section 5.1), indirect interpretive keys for site preparation (Section 5.2), and important site unit - wildlife habitat relationships (Section 5.3).
5.1 Silvicultural Systems Interpretations
This section is designed to assist the field guide user in the development of site- and stand-specific prescriptions for silvicultural systems that are compatible with stand management objectives. For the users of this section, a sound background knowledge of soils, tree silvics, stand development, and harvesting systems is assumed. This section is not intended as a substitute for adequate education, field experience, professional supervision, or training. Of course, this section should not be considered as a "cookbook" of recommended prescriptions.
The choice and execution of a silvicultural system in any given forest type must consider many site-specific and operational factors. The decision must be customized to the site type, stand structure, health, and vigour of the stand, and often unique combinations of local forest management objectives. For this reason, the decision cannot be reduced to simplistic duplication of standard, textbook techniques (Weetman et al. 1990). Smith (1986) has pointed out that "a rational silvicultural system for a particular stand should fit logically into the overall management plan for the forest of which the stand is a part. Second, it should represent the best possible amalgam of attempts to satisfy all . .. basic forest management objectives." A silvicultural prescription developed for any stand should consider and integrate eight basic site-specific objectives (adapted from Cole 1985 and Smith 1986):
• development of stand conditions necessary for meeting stand-level integrated resource management goals over the longest possible time;
• provision for regeneration;
• enough control over competing vegetation to allow establishment of adequate numbers of trees growing at acceptable rates;
• development or maintenance of stand structures, species compositions, and stand conditions that minimize damage from pests, wind, and fire;
• effective use of growing space, and maintenance or improvement of existing stand and site productivity;
• compatibility with acceptable logging practices, so that future stands can be cultured and harvested;
• efficient use of resources and arrangement of operations; and
• provision for periodic monitoring and assessment of long-term silvicultural performance.
237
5.1.1
The choice of an appropriate silvicultural system for a stand and site is complex and site-specific. The following materials are provided as decision aids. Careful examination of site characteristics and the existing stand will identify one or several ecologically suitable silvicultural system options. The final choice of a silvicultural system from these available options must be the best possible compromise of short- and long-term silvicultural objectives, technical (harvesting) feasibility, economic criteria, visual quality objectives (VQO's), and stand- and landscape-level biodiversity goals.
Steps for choosing an appropriate silvicultural system
In the preparation of the silviculture prescription for an area, the following 7-step procedure should be followed:
Step 1
Identify and establish priorities for short-term and long-term stand-level and landscape-level management objectives and constraints. Be specific. Translate objectives into general stand structure goals.
Step 2
Based on aerial photos and a thorough field reconnaissance of the stand and site, stratify the area into relatively homogeneous units (see Section 3.6). This is important, because attempts to combine information from markedly different strata will result in errors in interpretation over the entire area.
Step 3
All site, soil, and vegetation information for the strata should be collected as described in Section 3.4 and Section 4 of this field guide. In particular, map out blowdown-prone sites with high water tables or root-restricting soil layers.
Step 4
Collect detailed stand information as described in Section 5.1.2 in conjunction, if desired, with standard timber-cruising activities.
Step 5
Using the stand structure key (Figure 25) identify the "natural stand structure" of the existing stand based on total basal area of the C1 (overstory) and C2 (intermediate) crown classes, and total stems per hectare of the C3 (understory) and C4 (seedling) crown classes. Again using the key (Figure 25), identify the "effective stand structure" based on acceptable basal area of the C1 (overstory) and C2 (intermediate) crown classes, and acceptable stems per hectare of the C3 (understory) and C4 (seedling) crown classes.
238
STEP 1
Stratify planned cutblock area into relatively
homogeneous management units.
STEP 2 For each management unit, summarize stand information by:
1) Basal area in C1 and C2 layers
2) Stems/ha in C3 and C4 layers
Basal area of C1 layer
> 80% of total?
Combined basal area of
C1+ C2 > 20m 2 /ha?
Density of
C3 (understory)
> 1500 sph?
Density of
C3 + C4 layers
> 3000 sph?
Legend code crown class
Overstory
Intermediate
Understory
C1
C2
C3
C3 = regeneration > 1.3 m ht.
C4 = advance regeneration <1.3 m ht.
Basal area = cross-sectional area
of stems (at 1.3 m ht) in m 2 /ha
< 7.5 cm dbh
Density of
C3 (understory)
> 1500 sph?
IRREGULAR
TWO-STORIED
Density of
C3 + C4 layers
> 3000 sph?
SINGLE-
STORIED
MULTI-STORIED
NATURAL SHELTERWOOD
FIGURE 25. Key for identification of stand structure type (modified from Weetman et al., 1990).
239
Step 6
Based on the effective stand structure, use Table 10 to determine which silvicultural systems options are potentially suited to the site unit, stand structure, species composition of the existing stand, and site-specific ecological requirements of the desired tree species.
Step 7
Refer to the descriptions of the different silvicultural systems (Section 5.1.4). Determine which options identified in Step 6 are most likely to meet management objectives, constraints, and related stand structure goals as stated in Step 1. When the most desirable option is identified, a detailed Pre-Harvest Silviculture Prescription (PHSP) for that silvicultural system should be prepared in accordance with regional guidelines and procedures. If no silvicultural system options meet both the management objectives and constraints in the short term, then deferral or rejection of current harvesting proposals for the stand should be considered.
5.1.2 Collection of stand data
Stands and sites should be stratified into relatively homogeneous strata in the field before intensive sampling is started. The following data collection procedure has been developed in part from Weetman et al. (1990), Prince Rupert Forest Region (1991), and the Silviculture Interpretations Working Group (1992).
To determine potential silvicultural system options for a given stratum, detailed information on stand structure, vigour, condition, and species composition is required. Therefore, cruise data that is normally collected in all areas to be logged in B.C. must be supplemented with additional information. Stand information will be collected from fixed- radius or prism plots located in representative areas within each treatment unit. It is recommended that a minimum of four to five plots be systematically established in each stratum being evaluated for possible silvicultural system options. The plot size should be large enough to contain an average of 20 trees > 7.5 cm dbh. Data to be collected for each tree > 7.5 cm dbh include:
• Diameter • Species • Crown class, defined as:
C1 (Overstory) C2 (Intermediate)
= trees occupying top 1/3 of canopy = trees > 7.5 cm dbh occupying middle 1/3 of
• Indicate whether each tree is acceptable or unacceptable as post- canopy or possibly lower;
harvest leave-trees, where:
Acceptable leave-trees = stem free of rots, physical defects or
= species ecologically suited to site as per
= live crown ratio > 50% (> 40% for Fd)
pathological indicators
regional guidelines
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Unacceptable leave trees
= live crown ratio < 50% (< 40 % for Fd) = stem contains physical defects or
= species not ecologically suited to site as pathological indicators;
per regional guidelines.
Approved modifications to the above acceptability criteria may be required in specific localities to meet site-specific, non-timber integrated resource objectives.
To collect information on stems less than 7.5 cm dbh, a fixed-radius plot of 5.64 m radius (0.01 ha) should be established at the same plot centre as for other stand data collections. The following information should be recorded:
• Acceptable stems per hectare (sph) by
a) species; and
b) crown class, defined as
C3 (Understory)
C4 (Seedling)
= < 7.5 cm dbh but > 1.3 m height
= > 0.3 m height but < 1.3 m height
• Total sph by crown class (C3 and C4)
Finally, return to Step 5 in Section 5.1.1 to enter stand information into Figure 25. Stand data for each sampling strata should be summarized by:
• Acceptable basal area by species, and total basal area for each of the C1 and C2 crown classes; and
• Acceptable sph by species and total sph for each of the C3 and C4 crown classes.
Natural stand structure can be identified in Figure 25 using total basal area and sph while effective stand structure can be identified in Figure 25 using acceptable basal area and acceptable sph.
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TABLE 10. Potential silvicultural system options based on effective stand structure
Effective Clearcut Seed-tree Uniform Shelterwood One-cut Shelterwood / Selection / or Uneven- Stand Preparatory Cut Overstory Removal aged Structure
~ ~~~~~~ ~~
Single- Acceptable if compatible Fd only. Requires at least Fd, Sx, Bl, Hw, Cw. Light At least 1 preparatory or Difficult. At least 2-3 light storied with management 10-75 sph 1 of acceptable removal, leave at least 50% seed cut and successful stand entries needed to
objectives and site-specific dominant or co-dominant of original basal area. regeneration required create desired multi-storied ecological requirements of trees. Seedbed disturbance Seedbed disturbance before overstory removal. structure. At least 20-25 desired species. Clearcut required. required for Fd and Sx. m 2 /ha and 50% of basal Pl-major types with no Fd area must be retained. component. Sanitation cutting likely.
Natural Acceptable if compatible Fd only. Requires at least Not required if understory Ideal if advance At least 2 light to moderate Shelterwood with management 10-75 sph of acceptable can be protected and is regeneration can be stand entries needed to
objectives and site-specific dominant or co-dominant acceptable species, density, protected during harvest create desired stand ecological requirements of trees. Seedbed disturbance and quality. See and is of acceptable structure. At least 20-25 desired species. required. Shelterwood Overstory species, density, and m 2 /ha and 50% of basal
Removal. quality. area must be retained. Sanitation cutting.
Two-storied Acceptable if compatible Fd only. Requires at least Fd, Sx, Bl, Hw, Cw. Release C2 (intermediate) 1 or more stand entries with management 10-75 sph of acceptable Harvest intermediate layer layer if adequate stocking needed to stimulate new objectives and site-specific dominant or co-dominant and weaker co-dominant and quality. Basal area regeneration and create ecological requirements of trees. Seedbed disturbance trees. Light removal, leave stocking targets may be desired stand structure. desired species. required. at least 50% of original appropriate. As above for natural
basal area. Seedbed shelterwoods. disturbance required for Fd and Sx.
TABLE 10. (Continued)
Effective Clearcut Seed-tree Uniform Shelterwood One-cut Shelterwood / Selection / or Uneven- Stand Preparatory Cut Overstory Removal aged Structure
Multi-storied Acceptable if compatible Fd only. Requires at least Fd, Sx, Bl, Hw, and Cw. Release either C2 or Ideal initial structure. Cuts
with management 10-75 sph of acceptable Not necessary if understory C3/C4 layer if either must maintain and enhance objectives and site-specific dominant or co-dominant can be protected and is of crown class has adequate existing structure, quality, ecological requirements of trees. Seedbed disturbance acceptable species, density, stocking and quality. composition, and stocking. desired species. required. and quality. Selection Advance growth must be 20-25 m 2 /ha and 50% of
systems may be more protected. Selection basal area must be appropriate. systems also appropriate. retained.
Irregular Acceptable if compatible Fd only. Requires at least If sufficient stocking of As above for multi-storied At least 1 stand entry with management 10-75 sph of acceptable dominant and co-dominant stands. needed to attain target objectives and site-specific dominant or co-dominant layer. Harvest stand structure and ecological requirements of trees. Seedbed disturbance intermediates. Selection stocking. In previously
desired species. required. systems or overstory high-graded stands, an removal may be more appropriate.
extended cutting cycle may be necessary to allow basal area stocking to recover to optimum levels of 20 m 2 /ha or more. Sanitation cutting likely.
1 Stems per hectare
TABLE 11. Comparison of objectives of silvicultural system prescriptions
Silvicultural Goals of Prescription
Method Eventual Gap Width Establishment Release of Sanitation Quality Residual Maintain Approximated Stand Form Created of New Advance Removal of Increment Basal Area Specified
Produced Regeneration Regeneration Unacceptable on Large Objective Q-value, < 12.5 cm dbh Trees Stems > 12.5 Max dbh
cm dbh
Balanced Uneven-aged <1/2 H 1 max. Yes Yes Yes Yes Yes Yes Single-tree Selection
Small-group Selection Uneven-aged 2 H max. Yes Yes Yes, within Yes R 2 R
groups
Selection with Reserves
Uniform Shelterwood Even-aged <l/2 H max. Yes (Possible) Yes Yes Desirable -- 3
S helterwood openings
One-cut (Natural) Even-aged to Minimal Fill-planting of Yes Yes
Overstory Removal
Shelterwood with Reserves
Uneven-aged Similar to above selection options, but with long-term retention of appropriate stand components through one or more cutting cycles for biodiversity and integrated resource management objectives.
Group or Strip Even-aged 2Hmax. Yes (Possible) Yes, within R R
Shelterwood or Multi-aged gaps
Two-aged Similar to above shelterwood options, but with long-term retention of appropriate stand components through one or more rotations for biodiversity and integrated-resource management objectives.
TABLE 11. (Continued)
Silvicultural Goals of Prescription
Method Eventual Gap Width Establishment Release of Sanitation Quality Residual Maintain Approximated Stand Form Created of New Advance Removal of Increment Basal Area Specified
< 12.5 cm dbh Trees Stems > 12.5 Max dbh Produced Regeneration Regeneration Unacceptable on Large Objective Q-value
cm dbh
Uniform Seed-tree Even-aged 50 m max. Yes (Possible) Yes suggested
Seed Block Even-aged 100 m max. Yes (Possible) Yes, within suggested cut area
Seed-tree with Similar to above seed-tree options but with long-term retention of appropriate stand components through one or more Reserves rotations for biodiversity and integrated resource management objectives.
Clearcut Even-aged Variable, Planted or (Minor) Yes
Clearcut with Reserves Even-aged
Even-aged with veterans
> 100m natural
Similar to clearcut option but with long-term retention of appropriate stand components through one or more rotations for biodiversity and integrated resource management objectives. with veterans
1 H = Canopy height 2
3
R = Regulation of cut by percentage of total stand area harvested per stand entry. For group selection, < 33% of the stand area is harvested per stand entry. For group or strip shelterwood, > 33% of the stand area is harvested per stand entry.
- - = Minimal concern or not applicable
TABLE 12. Comparison of residual stand structures retained after initial partial cutting stand entry
Crown Classes Retained (1st Cut)
Reproduction Method Eventual Stand Gap Width C1 C2 C3 C4 Approximated Form Produced Created Overstory Intermediate Understory Seedling
Balanced Single-tree Uneven-aged <l/2 H 1 max. P 2 P P P
Small-group Selection Uneven-aged 2 H max. P P P c3
Selection
Selection with Reserves Uneven-aged Similar to above options, but with planned long-term retention of appropriate stand components through one or more cutting cycles for biodiversity and integrated resource management objectives.
Uniform Shelterwood Even-aged < l/2 H P T T T
Group or Strip Even-aged 2 H max. (Cut and leave patches are spatially separated) Shelterwood
One-cut (Natural) Shelterwood / Even-aged Minimal T T (P) C Overstory Removal
Shelterwood with Reserves Two-aged Similar to above options, but with planned long-term retention of appropriate stand components through one or more rotations for biodiversity and integrated-resource management objectives.
TABLE 12. (Continued)
Crown Classes Retained (1st Cut)
Reproduction Method Eventual Stand Gap Width C1 C2 C3 C4 Approximated Form Produced Created Overstory Intermediate Understory Seedling
Uniform Seed-tree Even-aged 50 m max. P T T T
suggested
suggested
Similar to above options but with long-term retention of appropriate stand component through one or more rotations for biodiversity and integrated resource management objectives.
Seed Block Even-aged 100 m max. (Cut and leave areas are spatially separated)
Seed-tree or Seed Block with Reserves
Even-aged with veterans
Clearcut Even-aged > 100 m T T T T
Clearcut with Reserves Even-aged with veterans
Similar to above options but with planned long-term retention of appropriate stand component for biodiversity and integrated resource management objectives.
1 H = Canopy height 2 P = Partial Retention (25-75%) 3
4 T = Total Removal (0% retention) C = Complete Retention (76-100%)
5.1.3 General terminology
Definitions of some key terms are essential for an understanding of silvicultural systems. A reproduction method is defined as any procedure (intentional or otherwise) that leads to the establishment of vigorous regeneration and growth of a new stand of trees (Smith 1986; Daniel et al. 1979). Reproduction methods can include the partial or complete removal of the old stand, establishment of the new one, and any treatments applied to create and maintain its early growth. Reproduction methods are broadly categorized by the pattern of cutting and the type of stand created. These include even-aged methods (clearcutting, seed-tree, or shelterwood) or uneven-aged (selection) methods (Smith 1986). The term "silvicultural system" is more comprehensive, however, and includes a planned program of silvicultural treatment throughout the life of a forest stand. This can include one or a series of reproduction cuttings, and any intermediate cuttings or other stand treatments. Tables 11 and 12 are useful comparisons of silviculture systems.
Stand structure is defined, for the purposes of these interpretations, as the vertical arrangement and stocking of trees within individual crown classes (canopy layers) in a stand. Stand structure types are described in Figure 25 and include single-storied, natural shelterwood, two-storied, multi-storied, and generally poorly stocked irregular stands. Natural stand structure (as referred to in Section 5.1.1, Step 5) describes the structure of an existing stand irrespective of any management interpretations. Effective stand structure (as referred to in Section 5.1.1, Step 5) is an interpretation of the natural stand structure. Determination of effective stand structure (Figure 25) focuses only on trees within the stand that meet physical acceptability criteria for given management objectives (see Section 5.1.2). Effective stand structure may or may not be equivalent to the natural stand structure. It will depend on the unique distribution of acceptable and unacceptable trees within an individual stand. Therefore, identification of silvicultural system options for a given stand, site, and management objective is based on effective stand structure and not the existing natural stand structure.
Partial cutting is a generic term that includes certain even-aged and uneven-aged reproduction methods. These methods involve the partial or complete post-harvest retention of specific crown classes or species from the original stand (seed-tree, shelterwood, and selection). The term "partial cutting" is widely used to refer to both present and historical harvesting methods that are not clearcutting (DeLong 1991). It should be stressed that a partial cutting method is not a reproduction method if it does not result in an adequately regenerated and stocked site. Like any reproduction method, a successful partial cutting treatment is only one element of a larger silvicultural system. For example, a partial cut designed to develop an uneven-aged stand is selection cutting only if subsequent operations are consistent with the original objective and result in the eventual development of the desired multi-layered stand.
It must also be stressed that the term selective logging should not be used in, or associated with, partial cutting prescriptions of any kind. Selective logging has no legitimate silvicultural or biological meaning. To professional foresters and many others, this term is associated with uncontrolled logging practices in the past that high-graded many stands
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of their most valuable and highest-quality growing stock (Weetman et al. 1990; Jull (in prep.) 1992).
5.1.4 Descriptions of reproduction methods
The ultimate distinction between reproduction methods is the form of forest produced. The size, shape, and position of the areas cut over, as well as the proportion of the timber removed, determine the arrangement of age classes within the stand. In a managed forest, each reproduction method is the chief factor governing forest form and, when systematically applied, produces a characteristic stand structure (Smith 1986).
The fundamental objective of all reproduction methods is the regeneration and perpetuation of a forest stand. Reproduction methods that use timber harvesting normally have wood production as one of their important objectives. Stands may also be managed partially or exclusively for the provision of other non-timber resources. These include habitat for many wildlife and wild plant species, landscape diversity, protection of water quality, scenic values, recreation, and spiritual values. Forests managed only for wood production do not necessarily contain characteristics that support other uses. Where it is decided that specified non-timber forest values should be integrated with conventional timber management, determinations must be made whether integrated management objectives can be best achieved at the stand or landscape level. It is not always practical, and may not be possible, to manage for all forest values within single stands. Similarly, it is unlikely that one silvicultural system, applied everywhere across the landscape, will achieve the diversity of forest values that is often desired.
Where specific combinations of forest resource values are to be integrated in the management of a single stand, the specific stand characteristics and components important to each resource value (eg., large dominant trees of a certain species, understory cover, or coarse woody debris) must be identified in the prescription. For example, cavity- nesting birds such as woodpeckers may require a certain number of large rotten trees to be maintained in the stand, or some ungulates may require winter range areas that have stands containing large arboreal lichen- bearing trees and snags. In many cases, specified stand characteristics can be incorporated within certain conventional silvicultural systems with, perhaps, long-term retention of certain live or dead trees for several rotations or cutting cycles. Specialized prescriptions in sensitive areas should be developed in consultation with appropriate agencies and organizations.
The success or failure of any silvicultural prescription should be evaluated by regular stand monitoring and by comparison to similar prescriptions carried out on similar site types located nearby. Long-term assessment carried out in this way will provide the feedback necessary to incorporate long-term results into future prescriptions.
5.1.4.1 Clearcutting methods
Background: The clearcutting method, like the seed-tree and shelterwood method, is a form of even-aged stand management. Clearcutting methods involve the complete removal of the entire stand
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in one cutting. Regeneration is obtained by planting, or by natural seeding from adjacent stands and cones shed from trees cut in the logging operation (Smith 1986). In concept, clearcutting is the simplest way of harvesting and replacing mature stands. It can mimic some of the conditions created by catastrophic disturbances. These conditions are responsible for regenerating certain species, particularly shade- intolerant and exposure-tolerant species. In some instances, catastrophic or rapidly deteriorating conditions in natural stands caused by insect epidemic, disease, fire, or very heavy incidence of rots or mistletoes will dictate the use of clearcutting.
Open area dominates and edge situations are minimal in a clearcut (Daniel et al. 1979). Clearcutting as a technical term should not be used to refer to heavy overstory removal cuttings that release new stands already established beneath them as advance growth. These types of cuttings are more appropriately referred to as one-cut (natural) shelterwoods and/or shelterwood overstory removals. The distinction is particularly important where site exposure after true clearcutting would greatly inhibit establishment of new seedlings. On such sites, preservation of pre-established advance growth can be a distinct silvicultural advantage.
Silvicultural Objectives: Regeneration after clearcutting can be achieved by natural regeneration, planting, or a combination of both. Under appropriate conditions, natural regeneration of conifers can occur by seeding from the stand edges adjacent to clearcuts, or, in the case of lodgepole pine, by lopping and scattering of serotinous cones during harvest operations. The clearcut system can have a number of advantages. Clearcutting is an efficient means of harvesting timber and completely clearing the site for (possible) intensive site preparation and planting of nursery-grown seedlings. Planting and even-aged plantation management can allow better control over a stand’s species and genetic composition than natural regeneration. Plantations can potentially allow establishment of more uniform and evenly stocked stands, provide prompt occupation of the site by trees where competing vegetation is a problem, and reduce natural regeneration delays. The disadvantages of clearcutting with planting include: high planting costs; risks of plantation failure; long-term costs of plantation maintenance (brushing, weeding, and thinning); and possible reduction of stand-level biodiversity in the absence of natural regeneration or retention of larger residual trees and organic debris.
Clearcutting methods are the simplest silvicultural systems to plan and harvest. By definition, clearcuts remove all of the original stand and advance regeneration is not specifically protected. Typically, site series, soil type, and terrain are the only determinants of logging method, desired species, stocking standards, and site preparation method. However, in extreme environments such as high-elevation sites, frost pockets, heavy snow zones, brush-prone areas, or areas with high sensitivity to mass wasting, the silvicultural benefits and costs of clearcutting systems should be assessed carefully. Because of undesirable aesthetic impacts, clearcutting should be used with discretion and in conjunction with careful planning in high-use recreational areas and highway scenic corridors. In particular, cutblock
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size, shape, and orientation may need to be modified to mitigate impacts.
Refer to Tables 11 and 12 to compare clearcutting systems with other silvicultural systems.
5.1.4.2 Seed-tree methods
Background: The seed-tree method is applied with the objective of naturally regenerating even-aged stands. A limited number of the best, most thrifty and windfirm trees or tree groups from the original stand are retained (10-75 sph) to provide a seed source for natural regeneration. Species and genotype of resulting natural regeneration can be influenced by selecting seed-trees of desirable species and form. Site preparation to expose mineral seedbeds may be necessary to stimulate natural regeneration establishment and reduce established brush competition. Seed-trees may be harvested when regeneration is obtained, or they may be retained through to the next rotation in order to meet wildlife, biodiversity, aesthetic, or future increment objectives.
Silviculture Objectives: Leave windfirm co-dominant and dominant trees that have the best ability to produce seed to the site. This ensures that regeneration objectives can be met wholly or in part by natural regeneration. Identified seed-trees must be conspicuously marked-to- leave with blue paint on all sides of the tree. Leave-trees should be healthy and have at least 40% live crown ratio (J. Revel, pers. comm., 1990). A sufficient number of trees should be left on windfirm areas to provide seed to the entire area for which natural regeneration is sought. This is commonly 10-75 sph (< 10 m2/ha). In the Prince George Forest Region, this is an appropriate system for Fd regeneration only. Bl, Hw, Cw and Sx are not consistently windfirm enough for exposure of single trees or small groups. On coarser-textured soils, or those with thin litter layers, summer logging activities may provide sufficient mineral soil exposure to stimulate Fd regeneration. On other areas, careful ground scarification (mineral soil exposure) will generally be necessary. Five to ten years will likely be required to achieve acceptable stocking of natural regeneration on seedbeds. This time frame is contingent on natural factors such as cone crop timing or vegetation competition. Conventional ground-based skidding or feller-bunchers can be used as long as root systems of leave-trees are not disturbed.
Refer to Tables 11 and 12 to compare seed-tree systems with other silvicultural systems.
5.1.4.3 Shelterwood methods
Background: Shelterwood methods are even-aged management techniques in which a stand of timber is gradually removed in a series of cuts. These cuts extend over a relatively short portion of the rotation and are intended to facilitate understory regeneration and development. Regeneration is established by natural seedfall or supplemented by under-planting, and growth occurs under the overhead or lateral shelter of an existing overstory. Preparatory shelterwood cuttings may be uniformly dispersed throughout the stand (uniform shelterwood), or they may take place as a series of edge cuttings in patches or strips
251
that are less than two tree heights wide (group or strip shelterwood). A portion of the stand in a group shelterwood may be reserved until later in the rotation creating a series of small, even-aged patches. In stands where an understory of acceptable natural regeneration already exists, one-cut shelterwoods, which completely remove overstory trees while protecting existing regeneration, are an option if the regeneration is tolerant of sudden exposure. Although the classical intent of a shelterwood is to eventually remove all of the overstory, modern variations may call for retention of part of the overstory in order to meet wildlife, biodiversity, aesthetic, or increment objectives.
Silviculture Objectives: For a preparatory shelterwood cut, leave at least 50% of the main tree canopy (C1 crown class) intact (75-200 sph or 10-30 m 2 /ha basal area). This will help maintain windfirmness, provide protection to young advance regeneration and new seedlings, and reduce understory vegetation competition. The trees will also serve, for a number of years, as an ongoing seed supply for natural regeneration. Many of the most thrifty and windfirm trees and tree groups are retained. Species and genotype of resulting regeneration under the shelterwood can be influenced by selection of shelterwood leave-trees of desirable species and form. Identified overstory leave- trees must be marked-to-leave on all four sides of the tree with conspicuous blue paint. Shelterwood preparatory cuts involve one or several overstory partial harvests. These are designed to gradually open up the canopy, simulate regeneration establishment and vigour, and create the desired stand structure in preparation for final overstory removal and regeneration release. This process will generally be completed 5-25 years after the first cut. Careful seedbed scarification (mineral soil exposure) is necessary for Fd and Sx regeneration establishment, and desirable for prompt establishment of Bl, Hw, and Cw. Conventional ground-based skidding or feller-bunchers can be used in summer (for Fd) or winter (for Sx, Hw, Cw, and Bl). It must be ensured that root systems of leave-trees are not disturbed. In some natural stands and old partial cuts, past light disturbances or other favourable conditions have stimulated the establishment of a vigorous, well-stocked advance regeneration layer. In such stands, preparatory cuts may be unnecessary, and one-cut (natural) shelterwoods with complete overstory removal may be feasible. Careful pre-harvest skid trail layout, appropriate logging machinery (ie., small tracked skidders), skilled operators, and intensive supervision are all important factors for ensuring the protection of existing regeneration. Post-harvest sanitation thinning will be necessary to remove badly scarred and broken stems of advance regeneration, especially those of subalpine fir.
Refer to Tables 11 and 12 to compare shelterwood systems with other silvicultural systems.
5.1.4.4 Selection methods
Background: Selection methods refer to a series of planned treatments and partial harvests designed to create or maintain managed, uneven- aged stands. An uneven-aged stand contains at least three well-defined, intermingled age classes (not just size classes). In single-tree selection, the management unit of interest is the individual tree, or very small clumps of trees less than one-half of canopy tree height in width. Group
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selection involves the management of discrete even-aged groups of trees. Under the group selection system, even-aged aggregations of trees in the stand are small by definition and have a width less than twice the height of the tallest trees. A single-tree selection system prescription must include regulation of cut by basal area and diameter distribution (q-value). Post-harvest maximum residual diameter of trees to be left should also be specified. Pre-harvest marking of trees to cut is strongly recommended as the means to achieve desired stand objectives. Group selection prescriptions include regulation of cut by the percentage of area harvested per stand entry. This is usually < 33%. Location of selected groups and access skid trails should be determined prior to harvest, and be designed to accommodate future volume removals. Regeneration is continuous from natural seedfall and may be supplemented by under-planting. Continuous forest cover is maintained. Variations upon the selection system can be complex and numerous. Further discussion can be found in Smith (1986), Daniel et al. (1979), Matthews (1989), or the Silviculture Interpretations Working Group (1992).
Silviculture Objectives: Leave as complete a distribution of age and size classes as possible while improving stand vigour and quality. A residual basal area of at least 20 to 25 m2/ha and 50% of the pre- harvest stand basal area must be protected and retained during harvest. Maximum residual diameter and diameter distribution (specified q-value) of stems in each diameter class must be determined for the PHSP and approximated operationally. The cutting cycle, or period of years between selection harvests, should be specified. A detailed inventory of all tree size classes, vigour, and pathological condition should be conducted (as per section 5.1.2). This assists in determining stand suitability and planning tree marking. Trees to be harvested should be marked-to-cut with conspicuous red paint on all sides of the tree or, conversely, acceptable trees marked-to-leave with blue paint.
As with shelterwood systems, important factors for achieving a successful selection stand entry are: careful and knowledgeable skid road and landing layout; appropriate logging machinery (ie., small tracked skidders); skilled operators; and rigorous harvest supervision. Winter logging on a compressible snowpack of 1 m is recommended to protect small advance regeneration from damage during stand entries. Post-harvest seedbed preparation may be necessary to create mineral soil seedbeds for Fd or Sx. Post-harvest sanitation thinning will be necessary to remove badly scarred and broken residual stems, especially those of subalpine fir.
Refer to Tables 11 and 12 to compare selection systems with other silvicultural systems.
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5.2 Site Preparation Keys
The keys provided in this section are intended to provide the user with a variety of site preparation treatment options based on the characteristics of the site for which treatments are prescribed. Two publications, Mechanical Site Preparation Equipment in North Central British Columbia (Coates and Haeussler 1987) and Site Preparation Strategies to Manage Soil Disturbance (Curran et al. 1990), were used extensively in preparing these keys. The keys are not meant to replace these documents and they should be consulted before making a final site preparation decision. Another useful reference is Chapters 11 and 12 in Regenerating British Columbia's Forests (Lavender et al. 1990). Before using the site preparation keys, site and soil information should have been collected and the site unit identified. The following steps should then be followed.
Step 1
Using Table 13, identify the appropriate soil grouping for the site unit using coarse fragment content and soil texture information previously collected.
Step 2
Using Table 14, identify the appropriate site group for the site unit you have previously identified.
Step 3
Proceed to appropriate site group key and, using site and soil information, advance step by step through the key until a site preparation code box is reached.
Step 4
Refer to site preparation code descriptions and decide which site preparation alternative best suits the site limitations and management objectives for the site.
TABLE 13. Soil grouping for all combinations of coarse fragment content and soil texture (from Curran et al. 1990)
Texture Coarse Fragment Content
< 30% 30 - 70% > 70%
S, LS, SL Coarse Very Coarse Very Coarse
vfSL, Loam Medium Coarse Very Coarse
SiL, Si Medium Medium Coarse
SC, SiC, SCL Fine Medium Medium
SiCL, CL, C Fine Medium Medium
S = sand, sandy Si = silt, silty
C = clay, clayey L = loam, loamy
vfSL = very fine sandy loam
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TABLE 14. Figure and page numbers for site preparation keys
SBSdw2/01,05 SxwFd - Pinegrass 27 258
SBSdw3/01
SBSmc2/01,04 Sxw - Huckleberry 27 258
SBSmc3/01 SBSmk1/01
SBSdw2/07 Pl - Pinegrass - Feathermoss 27 258 SBSdw3/05 and SbBl - Feathermoss SBSmc2/03 SBSmc3/05,06 SBSmk1/06 SBPSmc/03
SBSdk/01 Sxw - Twinberry - Step moss 26 256
SBSdw2/08 SBSdw3/06,07 SBSmc2/07 SBSmc3/07
SBSdk/06 Sxw - Thimbleberry - Dogwood 26 256
SBSmc2/05
SBSdw3/08 Sxw - Oak fern - Step moss 26 256
SBSmc2/06,08 SBSmk1/07
SBSdw2/09 Sxw - Devil's club - Oak fern 26 256
SBSmc2/09 SBSmk1/08
SBSdk/07,08 Sxw - Horsetail 28 259
SBSdw2/10 SBSmc2/10 SBSmc3/08 SBSmk1/09 SBPSmc/05
SBSdw3/09 Sxw - Horsetail - Glow moss 28 259
SBSmc2/11 SBPSmc/06
ESSFmv1/01 Bl - Rhododendron - Knight’s plume 29 260
ESSFmv1/04 Bl - Huckleberry 29 260
ESSFmv1/05 Bl - Horsetail - Sphagnum 28 259
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FIGURE 26. Site preparation key number 1 (wet sites).
* LGP vehicles must be used as prime mover for mechanical site preparation on these soils and soils must be dry or frozen.
FIGURE 26. (continued).
* LGP vehicles must be used as prime mover for mechanical site preparation on these soils and soils must be dry or frozen.
FIGURE 27. Site preparation key number 2 (moist sites).
FIGURE 28. Site preparation key number 3 (very wet sites).
* LGP vehicles must be used as prime mover for mechanical site preparation on these soils and soils must be dry or frozen.
FIGURE 29. Site preparation key number 4 (high elevation sites).
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SITE PREPARATION CODES
np: No Site Preparation - this option requires that slash reduction and alignment of slash become important components of the harvesting prescription (see Section 5.2.1). If brush hazard is high to extreme (see individual site unit interpretations), large sturdy stock should be planted in planter-prepared screefs. Areas receiving no site preparation should be monitored carefully to assess the need for brushing and weeding.
Brush Blading Normal - this technique includes all equipment capable of blading on sites up to 30% slope. The intent of this treatment is to pile slash and remove a portion of the organic layer without removing mineral soil. Increasingly complex microtopography makes this treatment more difficult to perform. A skilled operator, small equipment, and close supervision are required for this treatment to be effective without damaging the site.
Broadcast Burning - broadcast burning has been separated into severity classes based on Trowbridge et al. (1989) (see Table 15). Operational experience will be needed to meet the objectives stated in the tables. When prescribing a broadcast burn it is important to consider other units that may be included in the block to be harvested and are more sensitive to burning (eg., drier units with thinner humus layers or shallow soils). The probable impact of the treatment on these units will need to be determined. If the treatment is felt to be too severe for these other units, an attempt should be made to either exclude them from the block or guard these areas from the burn impact. Broadcast burning will generally stimulate species that regenerate from buried seed (eg., raspberry, currants, and gooseberries) or rhizomes (eg., thimbleberry). Brushing and weeding will be required if these types of species are present.
bn:
b#:
TABLE 15. Fuel consumption for different prescribed burning severities
Severity Fuel Consumption
Slash (%)
Duff <7 cm Diam. >7 cm Diam.
1 moss/litter 40 15
2 1-2 cm 50 20
3 2-5 cm 60-70 30
4 5-8 cm 80 40
5 8-15 cm 90 50
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ch: Chemical or Biological - this technique includes biological controls (eg., sheep) and any type of chemical or biological herbicide control. If prescribing this option, slash reduction and alignment of slash will become important components of the harvesting prescription (see Section 5.2.1). The Wildlife Interpretation section of this guide (Section 5.3) should be referred to when using this method so that important browse species for wildlife can be identified. Choose the treatment that best meets wildlife and site preparation objectives.
Drag Scarification - drag scarification can be used to prepare sites for planting but is more generally used to enhance natural regeneration of lodgepole pine. It is important to include a cone survey in the prescription when implementing drag scarification for natural regeneration. A lop-and-scatter clause may also need to be included if the harvesting is to be done by feller-bunchers. On sites with moderate or higher brush hazard (see individual site unit interpretations), the site should be carefully monitored in case brushing and weeding are required.
Excavator Mounding - this option requires that slash reduction and alignment of slash become important components of the harvesting prescription (see Section 5.2.1). As slash loading increases on slopes, the productivity of the excavator decreases. Vegetation growth generally increases with amount of organic matter incorporated in the mound capping. Careful monitoring will determine if brushing and weeding are required on sites with thick organic layers.
Excavator Patch Scarification - the intent of this treatment is to remove zero or a very limited amount of mineral soil during treatment. This option requires that slash reduction and alignment of slash become important components of the harvesting prescription (see Section 5.2.1). As slash loading increases on slopes, the productivity of the excavator decreases.
Light Piling - this category includes any equipment capable of placing slash in piles without the use of a blade (eg., rake with retractable teeth excavator). This equipment should be capable of piling while causing very minimal disruption of the upper soil layers, including the humus. There will be minimal effect on competing vegetation and no increase in soil warming using this treatment.
Mounding - this category includes all site preparation equipment capable of producing well-distributed raised profiles of organic and/or mineral soil. On sites where heavy slash accumulations are expected, alignment of slash will become an important component of the harvesting prescription (see Section 5.2.1). Vegetation growth generally increases with amount of organic matter incorporated in the mound capping. Careful monitoring will determine if brushing and weeding are required on sites with thick organic layers. Soils that are fine and have blocky structure should not be mounded, especially on drier sites or in drier biogeoclimatic units.
Motor Manual - this category includes brush saws and hand-held spot scarifiers. This option requires that slash reduction and alignment of slash become important components of the harvesting prescription (see
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Section 5.2.1). On sites where potentially competing species are present and will be stimulated by the action of the treatment chosen (eg., thimbleberry if spot scarifying), large sturdy stock should be planted.
Patch Scarification - this category includes all site preparation equipment capable of producing well-distributed patches of mineral soil for planting. The intent of this treatment is to remove the humus layer and a thin layer of mineral soil from the prepared patch. On sites where heavy slash accumulations are expected, alignment of slash will become an important component of the harvesting prescription (see Section 5.2.1). Patch scarification will generally stimulate species that regenerate from on-site seeding (eg., fireweed and grasses) or rhizomes (eg., thimbleberry). Brushing and weeding will be required if these types of species are present.
Trenching - this category includes all site preparation equipment capable of producing shallow continuous trenches (eg., disc trencher). Trenches should be made by contouring the slope where slopes are > 15%. Trenching will generally stimulate species that regenerate from on-site seeding (eg., fireweed and grasses). Brushing and weeding will be required if these types of species are present. Trees should usually be planted high up on the hinge in the units covered by this guide. Trench depth should never exceed 2/3 of the effective rooting depth on the site (see Table 2).
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5.2.1 Reducing slash during harvesting
Slash reduction to reduce fire and pest risks and improve planter access is often one of the reasons that site preparation is conducted. On ecologically sensitive sites, however, many site preparation techniques used to reduce slash may also damage the site. Slash can often be reduced during harvesting if the need is identified in the PHSP. There are several good references on the subject of reducing slash during harvesting. Two which should be referred to are Treatment of Logging Residues: Alternatives to Prescribed Burning (Hedin 1991) and Alternatives to Prescribed Burning (Burton 1991). Some of the techniques that can be used are slash alignment using feller-bunchers or grapples, increasing utilization, and on-site processing of residue (eg., chipping).
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5.3 Wildlife Interpretations
This section is included to provide information on stand and vegetation characteristics important to key wildlife species or species groups. Section 5.3.1 contains information on important habitat characteristics for some major wildlife species. For each ecological grouping (site group) there is a table provided that lists seral stages, vegetation, and special habitat components important to the species or species groups listed. Within the tables, bold text indicates species or habitat attributes of particular importance, normal type indicates general concern, and bracketed species or habitat components are of lower incidence or concern. To determine which table to use refer to Table 17. Descriptions of the information found in the tables and how it might be applied are outlined in the following text.
Seral Stage(s): these are defined on the basis of several attributes that change over time, including stand age, vegetation physiognomy, stand structure, mortality/replacement relationships and stand diversity. Figure 30 offers a schematic representation of various seral stages. The wildlife tables list which seral stages are important for selected wildlife species. In certain instances where seral stage features are of critical importance (eg., old growth), retention during harvesting may be necessary. The importance, extent, and distribution of a certain ecological unit/seral stage combination within a management area (eg., watershed) will assist in determining if the unit should be deferred from harvesting. The following descriptions are intended to assist in the recognition and classification of seral stages.
SH: Shrub - Herb - this stage develops after a disturbance in which the forest canopy is completely or significantly removed (eg., after clearcut logging or a severe fire) and typically lasts up to 15 years, although it may persist much longer. The vegetation is characterized by the dominance of shrubs and herbs; young trees are also abundant, although not dominant. Establishment is the primary process; biomass increases rapidly and floristic diversity is often high.
PS: Pole - Sapling - this stage typically begins 5 to 15 years after a disturbance, when the young trees overtop the shrubby or herbaceous vegetation. It usually lasts for up to 30 years, but may persist indefinitely - as in the case of some lodgepole pine stands in the Interior. Trees at this stage are characterized by their vigorous growth and lack of dead lower branches. Stands are more or less even-aged, having been planted or established naturally within a relatively short time. Establishment remains the dominant process, with stand biomass continuing to increase. Understory biomass declines as the canopy closes in.
YF: Young Forest - this stage begins when self-thinning becomes evident. A second cycle of trees begin to show a significant presence in the ground layer by the end of this stage. Differentiation of the initial tree species into dominant, co-dominant, and suppressed layers, and self- thinning, low stand diversity, and increasing biomass through rapid height growth are characteristic of this stage. Understory development is often limited by the dense forest canopy. This stage usually starts about 30 years after a succession-initiating disturbance and lasts for up to fifty years. In open forests where self-thinning may not be evident and a second cycle of trees is lacking, this stage will be characterized more
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Seral stage Seral plant association (common name) Site association
Shrub-herb (SH)
Pole-sapling (PS)
Young forest (YF)
Mature forest (MF)
Old-growth (OG)
$ Fireweed - Red raspberry
$ PI - Thimbleberry
$PI- Western hemlock
CWHW - Oak fern
CwHw - Oak fern
FIGURE 30. Example of forest structure associated with seral stages.
by the vigorous growth of the trees.
MF: Mature Forest - this stage extends until the initial trees mature, height growth slows, and some of the initial trees begin to die. A second cycle of trees may show a significant presence in the lower tree layers. In some cases, the first cycle of trees may begin to die from old age before significant development of a replacement layer begins; in other cases, the next cycle of trees may be well developed before significant mortality of the initial trees occurs. Generally, the even age distribution typical of early stages changes as new trees become established and older trees begin to die. Gap phase replacement may begin to be important at this stage. The understory re-develops as the canopy opens.
OG: Old-Growth - old-growth stands generally have an all-age class distribution. Growth slows and volume is lost through rot. Stands show structural heterogeneity as gaps develop in the canopy after trees fall. The understory biomass increases as light becomes available. The presence of dead wildlife trees and rotting logs scattered on the forest floor enhances the value of forests at this seral stage for wildlife. This stage often begins about 250 years after a succession-initiating disturbance.
Vegetation: this column within the tables indicates the species of vegetation important to the wildlife species listed for the site group. The species are generally listed by their scientific binomial, the first four letters indicating the genus and the second three letters indicating the species. Species presence and utilization is very important information to consider when choosing site preparation and brushing and weeding options. Information on how some vegetational species are affected by different treatments is provided in A Preliminary Guide to the Response of Major Species of Competing Vegetation to Silvicultural Treatments (Coates and Haeussler 1986). In certain cases (eg., Bryoria spp.) the species can only be retained by leaving older trees on the site.
Special Habitat Components: this column within the tables indicates which habitat components are important to the wildlife species being managed for. Many wildlife species are associated with a particular successional stage, usually the shrub - herb or the mature seral - old-growth stages. Timber management practices emphasize the pole - sapling and young forest stages, which are generally the least valuable for wildlife and have the lowest species diversity. However, management at the stand level can maintain some of the most important features of shrub - herb and old-growth forests, thereby increasing the stand’s value to wildlife throughout the rotation. The habitat components included in the table are described in the following commentary.
WT: Wildlife Trees - otherwise known as snags, these are important for cavity dwellers such as woodpeckers, common and Barrow’s goldeneye, marten and fisher. They also provide perching sites for owls and raptors and foraging substrates for insectivorous birds. Small wildlife trees are used only by small species; pileated woodpeckers, which excavate the larger cavities used by ducks and fisher, require wildlife trees of at least 26 cm dbh and preferably 40 cm.
CWD: Coarse Woody Debris - this includes sound and rotting logs and stumps and provides cover for small mammals and their predators. It is widely used by invertebrates and hence as a foraging substrate by
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insectivorous birds. CWD provides nesting and denning sites for birds and larger mammals and can be important in courtship rituals. It provides a sheltered environment for reptiles and amphibians that cannot tolerate extremes of temperature or drought. CWD also provides subnivean access routes that are particularly important for marten. Wildlife trees and CWD have a limited lifespan, depending on their size and degree of decomposition, and isolated wildlife trees are of limited value to wildlife. A preferred option would be to leave groups of wildlife trees with some large green trees (future wildlife trees), possibly where harvesting would be difficult or uneconomical. Wildlife trees and CWD are vulnerable to destruction by prescribed fire. However, large-diameter wood is generally only charred, especially if fire is used in spring or after heavy rain when fine fuels have dried out but larger fuels have not. Although charred logs are made more durable by fire hardening, they also become less valuable to wildlife in the short term as loose bark is removed and they are made too hard to be utilized by wood-boring insects or by cavity-excavating birds.
DT: Deciduous Trees - this component is important to songbirds such as warblers, vireos and flycatchers as foraging and nesting areas. Many primary cavity nesters prefer aspen and cottonwood to conifers, probably because cavity excavation is easier. Living and dead cottonwood trees are particularly important because of their large size.
SP: Slash/Brush Piles - this structural feature provides snow interception and cover for small birds and mammals. Because this is such an important structural attribute for voles, predators such as marten, fox, coyote, and weasels will also benefit. Leaving small slash piles unburned could increase populations of voles and porcupines.
ED: Edges - these occur between vegetation types (such as mature timber - clearcut or forested wetland - mesic forest) and are important for species that utilize either area. Species using both areas often prefer the juxtaposition of habitat types. Edges also provide habitat for species that prefer the transition zone (ecotone) between them. Induced edge effects can be maximized by creating a few smaller clearcuts instead of one large one, by creating irregularly shaped clearcuts, and by extending the time between passes. Maximizing edge may be detrimental to species that require large tracts of undisturbed habitat.
SA: South Aspects - this feature, because of increased solar radiation, is associated with reduced snow accumulation. This favours species such as mule deer, which do not tolerate deep snow. These areas are among the first sites to provide spring forage.
SU: Spring Use - occurs on those sites that provide important early season foraging opportunities. As such, it is closely related to southerly aspect and early disappearance of snow cover. These areas are important for hibernating species and for those that do not tolerate deep snow.
SL: Shelter - provides thermal and hiding cover for all wildlife species. It is particularly important for big game species during hunting and calving seasons. In winter, tree canopies intercept snowfall and minimize the energy expended in movement.
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OH: Open Habitats - these areas are important for production of Cladonia and Cladina lichens that constitute a critical food source for caribou in dry, pine-dominated stands.
LGS: Low-Gradient Streams - as one component of riparian habitats, these areas are extremely important for fish and wildlife. These areas provide a water source for many organisms and create a more moderate microclimate than is found in more upland forests. Streams may also function as corridors that facilitate genetic interchange, daily and seasonal movements, and range extension. Beaver prefer streams with gradients < 6%.
WE: Wetlands - these areas are found adjacent to the normal high water line around lakes, ponds, rivers, and streams. These habitats provide abundant vegetation for forage and cover, horizontal and vertical diversity, large invertebrate populations, water sources for drinking, and a more stable microclimate than the surrounding upland forests. Because of their high productivity, many wildlife species reach their highest densities in riparian habitats, especially in those adjacent to old-growth forests.
5.3.1 Habitat characteristics for species of management concern
Grizzly bear - early seral stages provide berries, especially huckleberries, soapberries, raspberries, and many others. Bears must have a variety of berry-bearing shrubs so that fruit is available throughout the summer. Protein-rich succulent herbs (horsetail, sedges, and cow parsnip) in riparian and seepage areas are particularly important in spring. Access to salmon streams is essential.
Beaver - use aspen/willow shrubs <10 cm dbh, near water; also riparian herbs in spring; preferred stream gradient is < 6%.
Red squirrel - population fluctuates with cone crop, primarily spruce; use groups of large conifers for nesting, coarse woody debris for food cache.
Coyote - use mostly early seral stages through young forest; often associated with edges/ecotones.
Gray wolf - depends on prey (beaver-sized or larger); no particular habitat requirements.
Red fox - use mostly early seral stages through young forest; often associated with edges/ecotones.
Cougar - depends on ungulate (chiefly deer) prey; no particular habitat requirements.
Lynx - dependent on snowshoe hare (found chiefly in shrubby stands or overstocked pine plantations 15-25 years old); den in blowdown in old growth.
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Wolverine - dependent on ungulate carrion; no particular habitat requirements although generally prefers upland coniferous forest; does not tolerate disturbance.
River otter - aquatic and riparian; often associated with beaver activity; uses logjams, coarse woody debris, and dense riparian shrubs and herbs.
Marten - uses mature forest and old growth, most common in productive forest with large down logs; highly dependent on coarse woody debris. Wildlife trees and brush piles are also used as den sites and access routes to subnivean hunting grounds.
Fisher - uses pole - sapling and young mixed forest in summer, mature forest and old growth in winter, possibly for snow interception; requires >50% crown closure; natal dens in large tree cavities; also uses coarse woody debris, slash piles, and edges/ecotones.
Striped skunk - opportunistic omnivore; prefers open forest and fore st edge.
Ermine - dependent on small mammals, chiefly voles; most common in early seral stages.
Long-tailed weasel - dependent on small mammals (chiefly voles) but also takes hares; most common in fairly early seral stages.
Least weasel - hunts mostly small voles and mice; prefers open areas, especially aspen parkland.
Mink - wetlands, riparian; dependent on emergent vegetation and riparian thickets; also uses brush piles, coarse woody debris, and logjams.
Black bear - uses wetland and seepage areas for grasses and sedges in early spring; early seral stages for berries in summer, especially raspberries, huckleberries, strawberries, and saskatoon; dens under tree roots, fallen logs, slash piles, and rock crevices.
Moose - uses wetland edges and areas of dense cover in summer; requires adequate densities of browse plants, chiefly willow and red-osier dogwood, in areas of reduced snow accumulation in winter. May move to mature or old-growth forest for protection from cold stress and in late winter for snow interception. Young aspen bark is important in spring.
Mule deer - uses old-growth coniferous forest, preferably on southerly aspects, with arboreal lichen and litterfall in winter, and dry, south-facing juniper slopes in early spring.
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TABLE 16. Bird species groups considered in the wildlife tables
Species Group Description Representative Species
A primary cavity-nesters, mainly in conifers. black-backed woodpecker, three-toed woodpecker
B
C secondary cavity-nesters.
primary cavity-nesters, mainly in deciduous trees
or wildlife trees. woodpecker.
red-breasted sapsucker, northern flicker, downy woodpecker, hairy woodpecker, pileated
Barrow’s goldeneye, common goldeneye, bufflehead, hooded merganser, common merganser, northern hawk owl, boreal owl, northern saw-whet owl, Vaux swift, many passerines; also bats.
cinnamon teal, American wigeon, ring-necked duck, lesser scaup, white-winged scoter.
warblers, vireos, flycatchers, thrushes; other migrating passerines.
crossbill.
D ground-nesters near water.
E
F mature coniferous forest dwellers.
eared grebe, Canada goose, green-winged teal, mallard, northern pintail, blue-winged teal,
deciduous tree and thicket dwellers.
northern goshawk, red-breasted nuthatch, brown creeper, Townsend’s warbler, red
TABLE 17. Table and page numbers for wildlife tables
Site Series Site Group Table Page Number Number
SBSdk
01 Sxw - Spirea - Sxw - Twinberry - Step moss 22 278
02 Pl - Juniper - Ricegrass Pl- Cladonia 18 274
81 Saskatoon - not assigned yet not not
03 Pl - Feathermoss - Cladina Pl - Kinnikinnick - 18 274 Feathermoss
04 Fd - Soopolallie - Fd - Pinegrass - Feathermoss 19 275
82 Bluegrass- not assigned yet not not
05 Sxw - Spirea - Feathermoss Sxw - Twinberry - Step moss 22 278
06 Sxw - Twinberry - Coltsfoot Sxw - Thimbleberry - 22 278
07 Sxw - Horsetail Sxw - Horsetail 23 279
08 Act - Dogwood - Prickly rose not assigned yet 23 279
09 Sb - Creeping snowberry - Sb - Sedge - Sphagnum 25 281
10 Sb - Soft-leaved sedge - Sb - Sedge - Sphagnum 25 281
SBSdw2
01 SxwFd - Pinegrass SxwFd - Pinegrass 20 276
02 FdPl - Cladonia FdPl - Pinegrass - 19 275 Feathermoss
03 Pl - Kinnikinnick - Pl - Kinnikinnick - 18 2 74 Wavy-leaved moss Feathermoss
04 Fd - Pinegrass - Aster Fd - Juniper - Pinegrass 19 275
05 SxwFd - Cat’s-tail moss SxwFd - Pinegrass 20 276
06 Pl - Pinegrass - Feathermoss Pl - Pinegrass - Feathermoss 18 274
07 PlSb - Feathermoss Pl - Pinegrass - Feathermoss 18 274
08 Sxw - Twinberry Sxw - Twinberry - Step moss 22 278
09 Sxw - Devil’s club - Sxw - Devil’s club - Oak fern 22 278
10 Sxw - Horsetail Sxw - Horsetail 23 279
11 Sb - Soft-leaved sedge - Sb - Sedge - Sphagnum 25 281
SBSdw3
01 SxwFd - Pinegrass SxwFd - Pinegrass 20 276
02 FdPl - Cladonia FdPl - Pinegrass - 19 275 Feathermoss
Purple peavine
Slender wheatgrass assigned assigned
Feathermoss
Slender wheatgrass assigned assigned
Dogwood
Sphagnum
Sphagnum
Knight’s plume
Sphagnum
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TABLE 17. (Continued)
Site Series Site Group Table Page Number Number
SBSdw3 (cont.)
03 Pl - Feathermoss - Cladina Pl - Kinnikinnick - 18 274 Feathermoss
04 SxwFd - Ricegrass SxwFd - Feathermoss 20 276
05 PlSb - Feathermoss Pl - Pinegrass - Feathermoss 18 274
06 Sxw - Pink spirea - Sxw - Twinberry - Step moss 22 278
07 Sxw -Twinberry Sxw - Twinberry - Step moss 22 278
08 Sxw-oak fern Sxw - Oak fern - Step moss 22 278
09 Sxw - Horsetail - Sxw - Horsetail - Glow moss 23 279
Prickly rose
Glow moss
Sphagnum 10 Sb - Soft-leaved sedge - Sb - Sedge - Sphagnum 25 281
SBSmc2
01 Sxw - Huckleberry Sxw - Huckleberry 21 277
02 Pl - Huckleberry - Cladonia Pl - Cladonia 18 274
03 SbPl - Feathermoss SbBl - Feathermoss 18 274
04 Sxw - Huckleberry - Sxw - Huckleberry 21 277
05 Sxw - Twinberry - Coltsfoot Sxw - Thimbleberry - 22 278
06 Sxw-Oakfern Sxw - Oak fern - Step moss 22 278
07 SXW - Scrub birch - Sxw - Twinberry - Step moss 22 278
08 Sxw - Twinberry - Oak Sxw - Oak fern - Step moss 22 278
09 Sxw - Devil’s club Sxw - Devil’s club - Oak fern 22 278
10 Sxw - Horsetail Sxw - Horsetail 23 279
11 Sxw - Horsetail - Sxw - Horsetail - Glow moss 23 279
Dwarf blueberry
Dogwood
Feathermoss
fern
Glow moss
Sedge 12 SbSxw - Scrub birch - Sb - Sedge - Sphagnum 25 281
SBSmc3
01 Sxw - Huckleberry SXW - Huckleberry 21 277
02 Pl - Juniper - Pl - Kinnikinnick - 18 274 Dwarf blueberry Feathermoss
03 Pl - Feathermoss - Cladina Pl - Kinnikinnick - 18 274 Feathermoss
04 Sxw - Huckleberry - Sxw - Huckleberry 21 277
05 Sb - Huckleberry - Spirea SbBl - Feathermoss 18 2 74
Soopolallie
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TABLE 17. (Continued)
Site Series Site Group Table Page Number Number
SBSmc3 (cont.)
06 SbPl - Feathermoss SbBl - Feathermoss 18 274
07 Sxw -Twinberry Sxw - Twinberry - Step moss 22 278
08 Sxw - Horsetail Sxw - Horsetail 23 279
09 SbSxw - Scrub birch - Sb - Sedge - Sphagnum 25 281
SBSmk1
01 Sxw - Huckleberry - Sxw - Huckleberry 21 277
02 Pl- Cladina - Step moss Pl - Cladonia 18 274
03 Pl - Feathermoss - Cladina Pl - Kinnikinnick - 18 274 Feathermoss
04 SxwFd - Knight’s plume SxwFd - Feathermoss 20 276
05 SxwFd - Toad-flax SxwFd - Feathermoss 20 276
06 Sb - Huckleberry - Spirea SbBl - Feathermoss 18 274
07 Sxw-Oakfem Sxw - Oak fern - Step moss 22 278
08 Sxw - Devil’s club Sxw - Devil’s club - Oak fern 22 278
09 Sxw - Horsetail Sxw - Horsetail 23 279
Sedge
Highbush-cranberry
10 Sb - Scrub birch - Sedge Sb - Sedge - Sphagnum 25 281
SBPSmc
01 Pl - Feathermoss - Cladina Pl - Kinnikinnick - 18 274 Feathermoss
02 Pl - Kinnikinnick - Pl - Cladonia 18 274
03 SbPl - Feathermoss Pl - Huckleberry - Cladonia 18 274
04 SXW - Sxw birch - Sxw - Twinberry - Step moss 22 278
05 Sxw - Horsetail Sxw - Horsetail 23 279
06 Sxw - Horsetail - Sxw - Horsetail - Glow moss 23 279
Cladonia
Feathermoss
Glow moss
Sedge 07 SbSxw - Scrub birch - Sb - Sedge - Sphagnum 25 281
ESSFmv1
01 Bl - Rhododendron - Bl - Rhododendron - 24 280
02 Pl - Huckleberry - Cladonia Pl - Cladonia 18 274
03 Bl - Huckleberry - Bl - Huckleberry 24 280
Feathermoss Knight’s plume
Feathermoss
Gooseberry 04 Bl - Huckleberry - Bl - Huckleberry 24 280
05 Bl - Horsetail - Glow moss Bl - Horsetail - Sphagnum 23 279
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TABLE 18. Information for wildlife species of management concern for dry lodgepole pine site groups a
Species Successional Important Forage Special Habitat Stage b Species Components c
(grizzly bear) SH MF OG Shepcan Calarub (PS YF) Rosa aci Spir bet
Rubu par
Bryo spp. Cladonia caribou MF OG (YF) Alec spp. Cladina OH
(black bear) (ALL) grasses cambium SU, SA, ED
coyote ALL SP, ED
ermine SH (ALL) SP, CWD
(gray wolf) (ALL)
lynx SH PS CWD, SP
(moose) MF OG (SH) Corn sto Abie las SL, ED, DT
YF of Pl
Amel aln Epil ang Rosa spp. Cala rub
Pseu men Betu pap Popu spp. Vacc spp.
(red fox) SH PS ED, SP
red squirrel (PS) YF MF WT, CWD
(mule deer) SH MF OG Alec spp. Bryo spp. SL, ED
OG
Popu tre Amel aln Sali spp. Betu pap
voles/mice ALL CWD, SP
chipmunks ALL CWD, SP
snowshoe hare PS YF SP, CWD
(porcupine) PS YF SP
(SH MF)
(Group B) MF OG WT, DT
(Group C) MF OG WT, DT
Group E ALL Vibu edu Ribe spp. DT, CWD
Group F ALL DT a
b
c
Site groups included are: Pl - Kinnikinnick - Feathermoss, Pl - Cladonia, Pl - Huckleberry - Cladonia, Pl - Pinegrass - Feathermoss, and SbBl - Feathermoss. SH - shrub - herb, PS - pole - sapling, YF - young forest, MF - mature forest, OG - old growth. OH - open habitats, SU - spring use, SA - south aspect, ED - edges, SP - slash/brush piles, CWD - coarse woody debris, SL - shelter, DT - deciduous trees, WT - wildlife trees.
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TABLE 19. Information for wildlife species of management concern for dry Douglas-fir site groups a
Species Successional Important Forage Special Habitat Stageb Species Components c
black bear ALL Cala rub Spir bet SU, SA, ED Shep can Rosa aci Abie las
cougar (ALL)
coyote ALL SP, ED
ermine ALL SP, CWD
(fisher) CWD
(gray wolf (ALL)
(lynx) PS CWD, SP
(marten) MF OG CWD, WT, SP
(moose) ALL Amel aln Popu tre SL, ED, DT
mule deer ALL Rosa aci Amel aln SA, ED Cala rub Oryz spp. Fest spp. Pens fru Agro spi
red fox ALL ED, SP
red squirrel MF OG WT, CWD
voles/mice SH OG CWD, SP
chipmunk ALL CWD, SP
(snowshoe hare) PS (YF) SP, CWD
(PS YF)
(PS YF MF)
(porcupine) ALL SP
Group A MF OG WT, DT
Group B MF OG WT, DT
Group C MF OG WT, DT
(Group E) (ALL) DT, CWD
Group F MF OG DT a
b
c
Site groups included are: Fd - Pinegrass - Feathermoss, Fd -Juniper - Pinegrass, and FdPl - Pinegrass - Feathermoss. SH - shrub - herb, PS - pole - sapling, YF - young forest, MF - mature forest, OG - old growth. SU - spring use, SA - south aspect, ED - edges, SP - slash/brush piles, CWD - coarse woody debris, WT - wildlife trees, SL - shelter, DT - deciduous trees.
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TABLE 20. Information for wildlife species of management concern for moist Douglas-fir site groups a
Species Successional Important Forage Special Habitat Stageb Species Componentsc
grizzly bear SH MF OG Cala rub Spir bet
black bear ALL Cala rub Spir bet SU, SA, ED
cougar ALL
coyote ALL SP, ED
ermine SH (ALL) S P , CWD
(PS YF) Rubu par Rosa aci
Rubu par Rosa aci
gray wolf (ALL)
(lynx) ALL CWD, SP
moose SH PS MF Corn sto Abie las SL, ED, DT OG (YF) Amel aln Epil ang
Rosa spp. Popu spp. Acer gla
red fox ALL ED, SP
red squirrel MF OG WT, CWD
mule deer SH OG PS Pseu men Acer gla SA, ED
PS YF
MF (YF) Rosa aci Abie las Paxi myr
voles/mice ALL (PS YF) CWD, SP
chipmunks ALL (PS YF) CWD, SP
(snowshoe hare) PS YF SP, CWD
porcupine PS YF MF SP
Group A MF OG WT, DT
Group B MF OG WT, DT
Group C MF OG WT, DT
(SH MF)
(Group D) CWD
Group E ALL Vibu edu Ribe spp. DT, CWD
Group F MF OG DT
Site groups included are: SxwFd - Pinegrass and SxwFd - Feathermoss. SH - shrub - herb, PS - pole - sapling, YF - young forest, MF - mature forest, OG - old growth.
SU - spring use, SA - south aspect, ED - edges, SP - slash/brush piles, CWD - coarse woody debris, SL - shelter, DT - deciduous trees, WT - wildlife trees.
a
b
c
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TABLE 21. Information for wildlife species of management concern for moist hybrid white spruce site groups a
Species Successional Important Forage Special Habitat Stage b Species Components c
grizzly bear ALL Spir bet Rosa aci Shep can Rubu par Equi arv
(beaver) SH PS YF Popu bal Sali spp. LGS, WE, DT
black bear ALL Rubu par Vacc mem SU, SA, ED
coyote SH PS SP, ED
ermine SH PS OG SP, CWD
(fisher) PS YF MF CWD, DT
gray wolf (ALL)
lynx SH PS CWD, SP
marten MF OG (SH) CWD, WT, SP,
moose SH PS MF Popu spp. Acer gla SL, ED, DT
Epil ang
OG
(YF MF OG)
ED
OG (YF) Sali spp. Abie las Vibu edu Sorb sit Rubu par Epil ang Corn sto Vacc spp.
red fox SH PS ED, SP
red squirrel PS YF MF WT, CWD
(mule deer) (ALL) Alec spp. Bryo spp. SL, ED
OG
Corn sto Rosa aci Pseu men
(wolverine) (ALL)
voles/mice SH OG CWD, WT, SP red-backed vole (PS YF MF)
snowshoe hare PS YF SP, CWD (SH MF OG)
porcupine (PS YF MF) SP
Group A MF OG (YF) WT, DT
Group B OG YF MF WT, DT
Group C OG MF WT, DT
(Group D) MF OG CWD
Group E ALL Vacc spp. DT, CWD
Group F MF OG DT
a
b
c
Site group included is Sxw - Huckleberry. SH - shrub - herb, PS - pole - sapling, YF - young forest, MF - mature forest, OG - old growth. LGS - low-gradient streams, WE - wetlands, DT - deciduous trees, SU - spring use, SA - south aspect, ED - edges, SP - slash/brush piles, CWD - coarse woody debris, WT - wildlife trees, SL - shelter.
277
TABLE 22. Information for wildlife species of management concern for wet hybrid white spruce site groups a
Species Successional Important Forage Special Habitat Stageb Species Components c
grizzly bear SH MF OG Vacc mem Rubu par (PS YF) Epil ang Equi spp.
Athy fil Hera lan
beaver SH PS YF Popu tre Sali spp. LGS, WE, DT
black bear SH MF OG Rubu par Vacc mem ED (PS YF) Epil ang
coyote SH SP, ED
ermine SH (ALL) SP, CWD
fisher YF MF OG WT, DT, CWD
gray wolf (ALL)
lynx SH PS OG CWD, SP
marten MF OG (SH) CWD, WT, SP,
moose SH PS MF Popu spp. Corn sto SL, ED, DT
(PS)
(YF)
ED
OG (YF) Sali spp. Abie Las Epil ang Ribe spp. Vibu edu Vacc spp.
red fox SH PS ED, SP
red squirrel MF OG WT, CWD
(mule deer) (ALL) Alec spp. Bryo spp. SL, ED
(wolverine) (ALL)
voles/mice SH OG CWD, WT, SP red-backed (PS YF MF) vole
snowshoe hare PS SH SP, CWD
porcupine PS YF MF SP
Group A MF OG (YF) WT, DT
Group B OG YF MF WT, DT
Group C OG MF WT, DT
(Group D) MF OG CWD
Group E SH PS YF DT, CWD
Group F MF OG Vacc spp. DT
(PS YF)
Rosa aci Abie las
(YF OG)
MF (OG)
a
b
c
Site groups included are: Sxw - Twinberry - Step moss, Sxw - Thimbleberry - Dogwood, Sxw - Oak fern - Step moss, and Sxw - Devil’s club - Oak fern. SH - shrub - herb, PS - pole - sapling, YF - young forest, MF - mature forest, OG - old growth. LGS - low-gradient streams, WE - wetlands, DT - deciduous trees, ED - edges, SP - slash/brush piles, CWD - coarse woody debris, WT - wildlife trees, SL - shelter.
278
TABLE 23. Information for wildlife species of management concern for very wet hybrid white spruce - subalpine fir site groups a
Species Successional Important Forage Special Habitat Stage b Species Components c
grizzly bear ALL Equi spp. Hera lan Ribe spp. Rosa aci Rubu spp. Gymn dry Athy fil
beaver SH PS YF Sali spp. Popu spp. LGS, WE, DT
black bear ALL Equi spp. Hera lan ED
(cougar) (ALL)
coyote SH PS YF SP, ED
ermine SH (ALL) SP, CWD
(fisher) PS YF MF WT, CWD, SP OG ED, DT
gray wolf (ALL)
lynx SH PS CWD, SP
marten MF OG (SH) WT, CWD, SP,
moose SH OG Sali spp. Equi spp. ED, SL
(OG YF)
ED
(PS YF MF) Corn sto Popu bal Abie las Urti dio Epil ang Ribe spp. Loni inv Vibu edu
(red fox) SH (PS YF) ED, SP
red squirrel MF OG WT, CWD
(mule deer) (ALL) Corn sto Sali spp. ED, SL
voles/mice SH OG CWD, WT, SP
(PS YF)
Ribe spp. Rosa aci
(PS YF MF)
(SH MF OG) (snowshoe hare) PS YF SP, CWD
Group A MF OG WT
Group B MF OG WT, DT
Group C MF OG WT, DT
Group E SH PS YF Vibu edu Ribe spp. DT
Group F MF OG DT
MF (OG)
a
b
c
Site groups included are: Sxw - Horsetail, Sxw - Horsetail - Glow moss, and Bl - Horsetail - Sphagnum. SH - shrub - herb, PS - pole - sapling, YF - young forest, MF - mature forest, OG - old growth. LGS - low-gradient streams, WE - wetlands, DT - deciduous trees, ED - edges, SP - slash/brush piles, CWD - coarse woody debris, WT - wildlife trees, SL - shelter.
279
TABLE 24. Information for wildlife species of management concern for moist subalpine fir site groups a
Species Successional Important Forage Special Habitat Stage b Species Components c
grizzly bear SH MF OG Equi spp. Hera lan
(caribou) MF OG Alec spp. Bryo spp.
(black bear) ALL Equi spp. Hera lan ED
(coyote) SH SP, ED
(PS YF)
ermine SH (ALL) SP, CWD
gray wolf (ALL)
(lynx) (ALL) CWD, SP
marten MF OG (SH) WT, SP, CWD,
moose SH MF OG Vacc spp. Samb rac SL, ED
ED
(PS YF) Rubu par Care spp. Forbs
red squirrel MF OG (PS YF) WT, CWD
voles/mice SH OG CWD, SP, WT red-backed vole (PS YF MF)
(snowshoe hare) PS YF SP, CWD
(Group A) MF OG WT
(Group C) MF OG WT, DT
Group E SH PS YF Vibu edu Ribe spp. DT
Group F MF OG DT
(SH MF OG)
a
b
c
Site groups included are Bl - Huckleberry and Bl - Rhododendron - Knight's plume. SH - shrub - herb, PS - pole - sapling, YF - young forest, MF - mature forest, OG - old growth. ED - edges, SP - slash/brush piles, CWD - coarse woody debris, WT - wildlife trees, SL - shelter, DT - deciduous trees.
280
TABLE 25. Information for wildlife species of management concern for very wet black spruce site groups a
Species Successional Important Forage Special Habitat stage b Species Components c
grizzly bear SH MF OG Equi spp. Care spp. SU
(beaver) SH PS YF Sali spp. Betu gla DT
black bear (ALL) Equi spp. Care spp. SU, ED
coyote SH SP, ED
ermine SH (ALL) SP, CWD
(fisher) PS YF MF OG SP, WT, CWD,
gray wolf (ALL)
long-tailed weasel PS SH (ALL) SP, ED
lynx SH PS YF CWD, SP
mink (ALL) CWD, SP
(PS YF)
ED, DT
(marten) MF OG WT, CWD, SP
moose ALL SH OG Sali spp. Betu gla SL, ED, DT
(mule deer) (ALL) SH OG SL, ED
(red squirrel) MF OG PS YF WT, CWD
striped skunk ALL ED
(wolverine) (ALL)
voles/mice (ALL) SH OG Loni inv Vibu edu CWD, SP
chipmunks ALL Corn can CWD, SP
(snowshoe hare) PS YF SP, CWD
porcupine (PS YF MF) SP
(Group D) SH YF MF OG ED
(Group E) ALL DT, CWD, SP
(Group F) MF OG DT, WT
Loni inv
(SH MF OG)
a
b
c
Site group included is Sb - Sedge - Sphagnum. SH - shrub - herb, PS - pole - sapling, YF - young forest, MF - mature forest, OG - old growth.
SU - spring use, DT - deciduous trees, ED - edges, SP - slash/brush piles, CWD - coarse woody debris, WT - wildlife trees, SL - shelter.
281
APPENDIX 1. New names for biogeoclimatic and site units in the southwest portion of the Prince George Forest Region
Old Biogeoclimatic Units and Ecosystem Associations Series
New Biogeoclimatic Units and Site
SBSd SBSdk
01 Mesic Rose - Peavine - Moss 01 Sxw - Spirea - Purple peavine
02 Pine - Lichen 02 Pl - Juniper - Ricegrass
03 Pine - Lichen - Moss 03 Pl - Feathermoss - Cladina
04 Saskatoon - Wheatgrass Scrub/Steppe 81 Saskatoon - Slender wheatgrass
05 Grasslands 82 Bluegrass - Slender wheatgrass
06 Douglas-fir - Soopolallie 04 Fd - Soopolallie - Feathermoss
07 Submesic Bunchberry - Moss 05 Sxw - Spirea - Feathermoss
08 Moist Shrub - Forb 06 Sxw - Twinberry - Coltsfoot
09 Spruce - Horsetail 07 Sxw - Horsetail
10 Cottonwood Bottomland 08 Act - Dogwood - Prickly rose
11 Spruce Swamps 10 Sb - Soft-leaved sedge - Sphagnum
12 Black Spruce Bogs 09 Sb - Creeping snowberry - Sphagnum
SBSk2 SBSdw2
01 Prickly rose - Bunchberry 01 SxwFd - Pinegrass
02 Douglas-fir - Lichen 02 FdPl - Cladonia
03 Pine - Velvet-leaved blueberry 03 Pl - Kinnikinnick - Wavy-leaved moss
04 Douglas-fir - Pinegrass 04 Fd - Pinegrass - Aster
05 Douglas-fir - Moss 05 SxwFd - Cat’s-tail moss
06 Pinegrass - Moss 06 Pl - Pinegrass - Feathermoss
07 Pine - Black spruce 07 PlSb - Feathermoss
08 Black twinberry - Coltsfoot 08 Sxw - Twinberry
09 Devil’s club - Oak fern 09 Sxw - Devil’s club - Knight’s plume
10 Spruce - Horsetail 10 Sxw - Horsetail
11 Bog Ecosystems 11 Sb - Soft-leaved sedge - Sphagnum
SBSk3 SBSdw3
01 Prickly rose - Queen’s cup 01 SxwFd - Pinegrass
02 Douglas-fir - Kinnikinnick 02 FdPl - Cladonia
03 Pine - Soopolallie - Moss 03 Pl - Feathermoss - Cladina
04 Wild Sarsaparilla - Prince’s pine 04 SxwFd - Ricegrass
05 Pine - Black spruce 05 PlSb - Feathermoss
No previous unit
06 Black twinberry - Coltsfoot 07 Sxw - Twinberry
07 Black twinberry - Oak fern 08 Sxw - Oak fern
08 Spruce - Horsetail 09 Sxw - Horsetail - Glow moss
09 Bogs 10 Sb - Soft-leaved sedge - Sphagnum
06 Sxw - Pink spirea - Prickly rose
282
APPENDIX 1. (cont.)
Old Biogeoclimatic Units and Ecosystem Associations Series
New Biogeoclimatic Units and Site
SBSe1 SBSmc2
01 Mesic Bunchberry - Moss 01 Sxw - Huckleberry
02 Pine - Lichen 02 Pl - Huckleberry - Cladonia
03 Pine - Lichen - Moss 02 Pl - Huckleberry - Cladonia
04 Submesic Bunchberry - Moss 01 Sxw - Huckleberry
05 Pine - Black spruce 03 SbPl - Feathermoss
05 Huckleberry - Dwarf blueberry 04 Sxw - Huckleberry - Dwarf blueberry
06 Moist Thimbleberry - Forb 05 Sxw - Twinberry - Coltsfoot
07 Oak fern 06 Sxw - Oak fern
08 Twinberry - Oak fern 08 Sxw - Twinberry - Oak fern
08 Devil’s club 09 Sxw - Devil’s club
09 Horsetail Flat 10 Sxw - Horsetail
10 Moist Poor Spruce - Glow moss 07 Sxw - Scrub birch - Feathermoss
11 Horsetail - Glow moss 11 Sxw - Horsetail - Glow moss
11 Fen and Swamp Ecosystem 12 SbSxw - Scrub birch - Sedge
SBSi SBSmc3
01 Prickly rose - Coltsfoot 01 Sxw - Huckleberry
02 Pine - Juniper 02 Pl - Juniper - Dwarf blueberry
03 Pine - Soopolallie 03 Pl - Feathermoss - Cladina
04 Soopolallie - Showy aster 04 Sxw - Huckleberry - Soopolallie
05 Prickly rose - Crowberry 05 Sb - Huckleberry - Spirea
06 Black twinberry - Crowberry 06 SbPl - Feathermoss
07 Black twinberry - Trailing raspberry 07 Sxw - Twinberry
08 Spruce - Horsetail 08 Sxw - Horsetail
not described 09 SbSxw - Scrub birch - Sedge
SBSe2 SBSmk1
01 Bunchberry - Moss 01 Sxw - Huckleberry - Highbush-cranberry
02 Soopolallie - Lichen 02 Pl - Cladina - Step moss
03 Kinnikinnick - Feathermoss 03 Pl - Feathermoss - Cladina
04 Douglas-fir - Subalpine fir 04 SxwFd - Knight’s plume
05 Ricegrass - Moss 05 SxwFd - Toad-flax
06 Pine - Black spruce 06 Sb - Huckleberry - Spirea
07 Highbush-cranberry - Oak fern 07 Sxw -Oak fern
08 Devil’s club - Lady fern 08 Sxw - Devil’s club
(Cariboo Region)
(Cariboo Region)
(Cariboo Region)
283
APPENDIX 1. (cont.)
Old Biogeoclimatic Units and Ecosystem Associations Series
New Biogeoclimatic Units and Site
SBSe2 (cont.) SBSmk1 (cont.)
09 Spruce - Horsetail 09 Sxw - Horsetail
10 Bogs 10 Sb - Scrub birch - Sedge
SBSa2 SBPSmc
01 Zonal Pine - White Spruce - Moss 01 Pl - Feathermoss - Cladina
02 Pine - Lichen 02 Pl - Kinnikinnick - Cladonia
03 Submesic Pine - Lichen - Moss 01 PI - Feathermoss - Cladina
04 Pine - Black spruce - Labrador tea 03 SbPl - Feathermoss
05 Moist Poor Pine - Spruce - Glow moss
06 Moist Rich White Spruce - Black 05 Sxw - Horsetail twinberry - Feathermoss
07 Wet White spruce - Mountain alder - 06 Sxw - Horsetail - Glow moss Horsetail - Leafy mosses
08 Black Spruce Bogs 07 SbSxw - Scrub birch - Sedge
ESSFmv1 ESSFmv1
01 Bl - Rhododendron - Feathermoss same
02 Pl - Huckleberry - Cladonia same
03 Bl - Huckleberry - Feathermoss - 03 Bl - Huckleberry - Feathermoss
04 Bl - Huckleberry - Feathermoss - 04 Bl - Huckleberry - Gooseberry
05 Bl - Horsetail - Glow moss same
04 Sxw - Scrub birch - Feathermoss
Blueberry
Currant
284
APPENDIX 2. Selected references for ecosystem description and interpretation, soils, vegetation, wildlife, and silvicultural systems for the southwest portion of the Prince George Forest Region
Ecology
Annas, R.M. and R. Coupé (editors). 1979. Biogeoclimatic zones and subzones of the Cariboo Forest Region. B.C. Min. For., Williams Lake, B.C.
B.C. Ministry of Forests, Cariboo Forest Region. 1987. A field guide for the identification and interpretation of ecosystems of the Cariboo Forest Region. Revised ed. B.C. Min. For., Williams Lake, B.C.
DeLong, C., G. Hope, and A. McLeod. 1984. A field guide for the identification and interpretation of ecosystems of the SBSe2 in the Prince George Forest Region. First approx. B.C. Min. For., Prince George, B.C. Draft report.
. 1985. A field guide for the identification and interpretation of ecosystems of the SBSi in the Prince George Forest Region. First approx. B.C. Min. For., Prince George, B.C. Draft report.
. 1987. A field guide for the identification and interpretation of ecosystems of the SBSk3 in the Prince George Forest Region. First approx. B.C. Min. For., Prince George, B.C. Draft report.
Delong, C. and A. McLeod (compilers). 1985. A field guide for the identification and interpretation of ecosystems of the SBSk2 in the Prince George Forest Region. First approx. B.C. Min. For., Prince George, B.C. Draft report.
Illingworth, K. and J.W.C. Arlidge. 1960. Interim report on some forest types in lodgepole pine and spruce - subalpine fir stands. B.C. Dep. Lands For., For. Serv., Victoria, B.C. Res. Note No. 35.
Lewis, T., J. Pojar, D. Holmes, R. Trowbridge, and K.D. Coates. 1986. A field guide for identification and interpretation of the Sub-Boreal Spruce zone in the Prince Rupert Forest Region. B.C. Min. For., Victoria, B.C. Land Manage. Handb. No. 10.
Pojar, J., R. Trowbridge, and D. Coates. 1984. Ecosystem classification and interpretation of the Sub-Boreal Spruce zone, Prince Rupert Forest Region, British Columbia. B.C. Min. For., Victoria, B.C. Land Manage. Rep. No. 17.
Pojar, J., R. Trowbridge, and T. Lewis. 1982. Biogeoclimatic zones of the Cassiar Timber Supply Area, northwestern British Columbia. B.C. Min. For., Smithers, B.C.
Revel, R.D. 1972. Phytogeocoenoses of the Sub-Boreal Spruce biogeoclimatic zone in north central British Columbia. Ph.D. thesis. Univ. B.C., Vancouver, B.C.
285
Wali, M.K. and V.J. Krajina. 1973. Vegetation - environment relationships of some Sub-Boreal Spruce zone ecosystems in British Columbia. Vegetatio 26: 237-381.
Soils
Cotic, I. 1974. Soils of the Nechako - Francois Lake area. B.C. Dep. Agric., Kelowna, B.C. Interim report.
Dawson, A.B. 1989. Soils of the Prince George - McLeod Lake area. B.C. Min. Environ. and B.C. Min. Agric. and Fisheries, Victoria, B.C. Min. Environ. Tech. Rep. No. 29.
Farstad, L. and D.G. Laird. 1954. Soil survey of the Quesnel, Nechako, Francois Lake and Bulkley - Terrace areas. B.C. Soil Survey, Can. Dep. Agric., Ottawa, Ont. Rep. No. 4.
Vegetation
Coupé, R., C.A. Ray, A. Comeau, M.V. Ketcheson, and R.M. Annas (compilers). 1982. A guide to some common plants of the Skeena area, British Columbia. B.C. Min. For., Victoria, B.C. Land Manage. Handb. No. 4.
Pojar, J., R. Love, D. Meidinger, and R. Scagel. 1982. Some common plants of the Sub-Boreal Spruce zone. B.C. Min. For., Victoria, B.C. Land Manage. Handb. No. 6.
Wildlife
Armleder, H.M., R. J. Dawson, and R.N. Thomson. 1986. Handbook for timber and mule deer management co-ordination on winter ranges in the Cariboo Forest Region. B.C. Min. For., Victoria, B.C. Land Manage. Handb. No. 13.
Wildlife Branch. 1989. Regional wildlife habitat maps. B.C. Min. Environ., Victoria, B.C.
Child, K. and D. King. 1988. Regional Wildlife Plan for the Omineca Sub-Region, Northern Region. Min. Environ., Wildlife Branch. Prince George, B.C.
Silvicultural Systems
Alexander, R.R. 1987. Ecology, silviculture, and management of the Engelmann spruce - subalpine fir type in the central and southern Rocky Mountains. U.S. Dep. Agric. For. Serv., Agric. Handb. No. 659.
Klinka, K., and R.E. Carter. 1991. A stand-level guide to the selection of reproduction methods for regenerating forest stands in the Vancouver Forest Region. B.C. Min. For., Vancouver Forest Region, Burnaby, B.C. Contract report.
Filip, G.M. and C.L. Schmitt. 1990. Rx for Abies: silviculture options for diseased firs in Washington and Oregon. U.S. Dep. Agric. For. Serv., Gen. Tech. Rep. PNW-252. Pac. Northwest Res. Stn., Portland, Oregon.
286
Jull, M.J. 1991. Evaluating partial-cutting practices for old-growth stands in the ESSFh3 subzone: Discussion paper. B.C. Min. For., Prince George Forest Region, Prince George, B.C. Contract report.
Jull, M.J. [1993]. Current and historical partial-cut reproduction methods and opportunities for silvicultural system development in the Prince George and Robson Valley Forest Districts. B.C. Min. For., Prince George Forest Region, Prince George, B.C. In prep.
287
6 LITERATURE CITED
B.C. Ministry of Forests, Cariboo Forest Region. 1987. A field guide for the identification and interpretation of ecosystems of the Cariboo Forest Region. Revised ed. B.C. Min. For., Williams Lake, B.C.
Braumandl, T.F. and M.P. Curran (editors). 1992. A guide to site identification and interpretation for the Nelson Forest Region. B.C. Min. For., Victoria, B.C., Land Manage. Handb. No. 20.
Burton, G.D. (compiler and editor). 1991. Alternatives to prescribed burning. B.C. Min. For., Victoria, B.C. Contract report.
Coates, D. and S. Haeussler. 1986. A preliminary guide to the response of major species of competing vegetation to silvicultural treatments. B.C. Min. For., Victoria, B.C., Land Manage. Handb. No. 9.
Coates, D. and S. Haeussler. 1987. A guide to the use of mechanical site preparation equipment in north central British Columbia. Revised 2nd ed. A. MacKinnon, L. Bedford, and J. Maxwell. Min. For., Victoria, B.C. and For. Can., Victoria, B.C. FRDA Res. Handb. No. 2.
Cole, D.M. 1985. Acceptable silviculture systems in relation to desired stand character and successional roles of lodgepole pine. In Integrating management strategies for the mountain pine beetle with multiple- resource management of lodgepole pine forests. M. MacGregor and D.M. Cole (editors). U.S. Dep. Agric. For. Serv., Intermountain Forest and Range Exp. Stn., Gen. Tech. Rep. INT-174, pp.45-56.
Courtin, P.J., R.N. Green, and G. Shishkov. 1989. An ecological approach to organizing forests for woodlot management. B.C. Min. For., Victoria, B.C., Land Manage. Handb. Rep. No. 58.
Curran, M., B. Fraser, L. Bedford, M. Osberg, and B. Mitchell. 1990. Site preparation strategies to manage soil disturbance. B.C. Min. For., Victoria, B.C. Land Manage. Handb. No. 5, Field Guide Insert 2.
Daniel, T.W., J.A. Helms, and F.S. Baker. 1979. Principles of silviculture, 2nd ed. McGraw-Hill Series in Forest Resources. New York, N.Y.
DeLong, C., G. Hope, and A. McLeod. 1984. A field guide for the identification and interpretation of the ecosystems of the SBSe2 in the Prince George Forest Region. First approx. B.C. Min. For., Prince George, B.C. Draft report.
. 1985. A field guide for the identification and interpretation of ecosystems of the SBSi in the Prince George Forest Region. First approx. B.C. Min. For., Prince George, B.C. Draft report.
. 1987. A field guide for the identification and interpretation of ecosystems of the SBSk3 in the Prince George Forest Region. First approx. B.C. Min. For., Prince George, B.C. Draft report.
288
Delong, D. 1991. Partial-cutting prescriptions in southern B.C. Forest Engineering Research Institute of Canada, Western Division, Vancouver, B.C. Interim report.
Green, R.N., K. Courtin, K. Klinka, R.F. Slaco, and C.A. Ray. 1984. Site diagnosis, tree species selection and slashburning guidelines for the Vancouver Forest Region. B.C. Min. For., Victoria B.C., Land Manage. Handb. No. 8.
Hedin, I.B. 1991. Treatment of logging residues: alternatives to prescribed burning. Forest Engineering Research Institute of Canada, Western Division, Vancouver, B.C. Contract report.
Jull, M.J. [1993]. Current and historical partial-cut reproduction methods and opportunities for silvicultural system development in the Prince George and Robson Valley Forest Districts. B.C. Min. For., Prince George, B.C. Draft report. In prep.
Krajina, V.J. 1965. Biogeoclimatic zones and biogeocoenoses of British Columbia. Ecol. West. N. Amer. 1:1-17.
. 1969. Ecology of forest trees in British Columbia. Ecol. West. N. Amer. 2: 1-146.
Lavender, D.P., R. Parish, C.M. Johnson, G. Montgomery, A. Vyse, R.A. Willis, and D. Winston (editors). 1990. Regenerating British Columbia’s forests. For. Can., Victoria, B.C. and B.C. Min. For., Victoria, B.C. Dist. by Univ. B.C. Press. Vancouver, B.C.
Lewis, T., J. Pojar, D. Holmes, R. Trowbridge, and D. Coates. 1986. A field guide for the identification and interpretation of the Sub-Boreal Spruce Zone in the Prince Rupert Forest Region. B.C. Min. For., Victoria, B.C. Land Manage. Handb. No. 10.
Lloyd, D., K. Angove, G. Hope, and C. Thompson. 1990. A guide to site identification and interpretation for the Kamloops Forest Region. B.C. Min. For., Victoria, B.C., Land Manage. Handb. No. 23.
Luttmerding H.A., D.A. Demarchi, E.C. Lea, D.V. Meidinger, and T. Vold (editors). 1990. Describing ecosystems in the field. 2nd ed. B.C. Min. For., Victoria, B.C. and B.C. Min. Environ., Victoria, B.C. Min. Environ. Manual No. 11.
MacKinnon, A., J. Pojar, and R. Coupé (editors). 1992. Plants of northern British Columbia. B.C. Min. For., Victoria, B.C. Lone Pine Publishers, Edmonton, Alta.
Matthews, J.D. 1989. Silviculture systems. Oxford University Press. New York, N.Y.
Meidinger, D. and J. Pojar (editors). 1991. Ecosystems of British Columbia. B.C. Min. For., Victoria, B.C. Special Rep. Series No. 6.
289
Mitchell, W.R., R.N. Green, G.D. Hope, and K. Klinka. 1989. Methods for biogeoclimatic ecosystem mapping. B.C. Min. For., Victoria, B.C. Res. Rep. 89002-KL.
Pojar, J., K. Klinka, and D.V. Meidinger. 1987. Biogeoclimatic ecosystem classification in British Columbia. For. Ecol. Manage. 22:119-154.
Prince Rupert Forest Region. 1991. Interim procedures for preparation of partial cut pre-harvest silviculture prescriptions. B.C. Min. For., Smithers, B.C. Silviculture Manual Insert "L".
Silviculture Interpretations Working Group. 1992. First approximation of correlated guidelines for management of uneven-aged dry-belt Douglas-fir stands in British Columbia. B.C. Min. For., Victoria, B.C. Draft No. 5.
Silviculture Regulations. 1988. B.C. Reg 147/88; O.C. 593/88. Queen’s Printer, Victoria, B.C.
Smith, D. 1986. The practice of silviculture. 8th ed. John Wiley and Sons, New York, N.Y.
Trowbridge, R., S. Schmidt, and L. Bedford. 1989. Prescribed Fire Severity Guidelines for the Moist Cold Sub-Boreal Spruce Subzone in the Prince Rupert Forest Region. First Approx. B.C. Min. For., Victoria, B.C. Sub- Boreal Spruce Zone Field Guide Insert.
Weetman, G.F., E. Panozzo, M. Jull, and K. Marek. 1990. An assessment of opportunities for alternative silviculture systems in the SBS, ICH, and ESSF biogeoclimatic subzone of the Prince Rupert Forest Region. B.C. Min. For., Smithers, B.C. Contract report.
290