animal damage to coniferous plantations in oregon and

arcl bulletin 25Cam

0 7t 5

may 1979

animal damageto coniferous plantationsin Oregon and Washington

dart 1. a survey,1963-1975

Hugh C. BlackEdward J. Dimock IIJames Evans.James A. Rochelle

Since 1941, the Forest Research Labo-ratory-part of the School of Forestryat Oregon State University in Corval-lis-has been studying forests and whythey are like they are. A staff of morethan 50 scientists conducts research toprovide information for wise public andprivate decisions on managing and usingOregon's forest resources and operatingits wood-using industries. Because ofthis research, Oregon's forests nowyield more in the way of wood prod-ucts, water, forage, wildlife, and recrea-tion. Wood products are harvested,processed, and used more efficiently.Employment, productivity, and profit-ability in industries dependent on for-ests also have been strengthened. Andthis research has helped Oregon tomaintain a quality environment for itspeople.

Much research is done right in theLaboratory's facilities on the campus.But field experiments in forest genetics,young-growth management, foresthydrology, harvesting methods, and re-forestation are conducted on 12,000acres of School forests adjacent to thecampus and on lands of public andprivate cooperating agencies throughoutthe Pacific Northwest.

With these publications, the Forest Re-search Laboratory supplies the resultsof its research to forest land ownersand managers, to manufacturers andusers of forest products, to leaders ofgovernment and industry, and to thegeneral public.

As a research bulletin, this publicationis one of a series that comprehensivelyand in detail discusses a long, complexstudy or summarizes available informa-tion on a topic.

the authorsHugh Black-formerly associate pro-fessor in the Department of ForestScience, School of Forestry, OregonState University-now is a regionalwildlife ecologist with the U.S. ForestService, Region 5, San Francisco, Calif.94111. Edward Dimock II is principalsilviculturist with the U.S. Forest Serv-ice, Pacific Northwest Forest andRange Experiment Station, Corvallis,Oreg. 97331. James Evans is leader ofthe forest-animal research project, U.S.Fish and Wildlife Service, Olympia,Wash. 98502. James Rochelle is man-ager of environmental sciences, Weyer-haeuser Company, Forestry ResearchCenter, Centralia, Wash. 98531.

acknowledgmentsThis study could not have been com-pleted without the support and cooper-ation of many individuals and organiza-tions. Industrial forestry companies andpublic-land managing agencies installedsampling plots, made initial measure-ments of tree heights, and gave otherassistance. The Cooperative AnimalDamage Survey Committee chaired byWilliam Looney of Simpson TimberCompany, assisted with planning andcoordination. Edward F. Hooven andRichard P. Newman, Oregon StateUniversity; Glenn L. Crouch (now atthe Rocky Mountain Forest and RangeExperiment Station), Pacific NorthwestForest and Range Experiment Station,U.S. Forest Service; Dan. L. Campbelland Wendell E. Dodge (now Leader,Massachusetts Cooperative Wildlife Re-search Unit), U.S. Fish and WildlifeService; Harry D. Hartwell and LarryE. Johnson, Washington State Depart-ment of Natural Resources; William H.Lawrence and Donald Swanson, Weyer-haeuser Company; and others helpedwith field examinations and data tabu-lation- for the first 5 years. Kenneth,Wilmarth, Colorado State University;Louella Spencer, WeyerhaeuserCompany; and Charles Loveless, PaulHegdal, and John Oldermeyer, U.S.Fish and Wildlife Service, assisted withprogramming and data analysis forthose years. Glenn L. Crouch, GordonFisch (now at the Alaska Forest Serv-ice, Forestry Sciences Laboratory,Juneau, Alaska), Floyd A. Johnson,and Pat Williams, Pacific NorthwestForest and Range Experiment Station,helped tabulate, program, and analyzedata collected during the last 5 yearsof the survey. -

disclaimerThe mention of trade names or com-mercial products in this publicationdoes not constitute endorsement orrecommendation for use.

to order copiesCopies of this and other Forest Re-search Laboratory publications areavailable from:

Forest Research LaboratorySchool of ForestryOregon State UniversityCorvallis, Oreg. 97331

Please include author(s), title, and pub-lication number if known.

contents

4

preface

summarytypes and causesimpact on survivalimpact on height

introductionproceduresplot examinationcontinued examination

douglas-fir plots: years 1-56 animal damage8 plot10 distribution10 minor types

10 survivald

11 growth14 damage and plot features14 ownership15 slash treatment

15 aspect

15 slope

15 site quality

16 elevation16 stock class

16 tree age and damage occurrence16 barking16 browsing16 budding16 clipping

18 pine plots: years 1-518 animal damage19 survival19 growth

1

3

4

5

6

20 selected douglas-fir plots: years 1-1020 animal damage21 survival22 growth

24 individual plot histories24 succession of damage agents24 budding by grouse25 clipping by rodents25 ponderosa pine25 douglas-fir

26 browsing and trampling by domestic stock28 browsing by deer

30 discussion30 caging30 stand maintenance30 damage distribution31 damage to saplings and trees31 damage agents31 impact of damage

32 conclusions33 references cited34 appendix tables44 checklist of plants and animals

preface

The Cooperative Animal DamageSurvey Committee conducted thissurvey in coordination with theNorthwest Forest Pest Counciland the Western Forestry andConservation Association togather information that forest-industry and forest-managingagencies needed on the natureand significance of mammal andbird damage to plantations ofDouglas-fir and ponderosa pine.

This description of animal damageprovides a benchmark for asses-sing future damage to forest plan-tations. Comparisons of caged anduncaged trees provide a measureof the survival and growth, disre-garding animal damage, of refor-ested Douglas-fir and pine inOregon and Washington.

An economic analysis and itsimplications, based on computersimulation models that projectplantation development with var-ying amounts of animal damage,is contained in a second report,Part 11, by J. Douglas Brodie,Hugh C. Black, Edward J.Dimock 11, James Evans, ChiangKao, and James A. Rochelle.

summary

This report evaluates the impactof animal damage on survival andgrowth of Douglas-fir [Pseudo-tsuga menziesii (Mirb.) Franco]and ponderosa pine (Pinus pon-derosa Laws.) in Oregon andWashington. That evaluationdraws on mammal and bird dam-age recorded on Douglas-fir andponderosa pine plots randomlyestablished in 1963-64, then ob-served for 5 to 10 years.

Forest land owners planting50,000 or more seedlings during1962-63 (first series) or 1963-64(second series) were potentialparticipants in the survey; plan-tations east of the Cascade Moun-tains were not sampled in thesecond series. In all, 194 samplingplots were installed. Ten of the110 seedlings on each plot werecaged to protect them from ani-mals. All trees were marked withstakes, then examined after plant-ing and after bud burst each yearfor 5 years. Observations of a

selected sample of 45 Douglas-firplots were continued for 10 yearsto study long-term patterns andeffects of severe plantation dam-age.

Then survival and growth ofcaged trees were compared withthe survival and growth of un-caged trees exposed to animaldamage. The agents, kind,amount, and distribution of thatdamage were evaluated by state,by subregion, and by relation tosite features.

types and causesAnimals damaged an average of30 percent of all unprotectedDouglas-fir trees each year on the165 plots in Oregon and Washing-ton. (Percentages are expressed inwhole units throughout this text.Appendix tables give more refineddata.) Browsing (22%) was by farthe most common type of dam-age to Douglas-fir. Clipping (6%)and budding (3%) were also com-mon and widespread. Trampling,barking, pulling of seedlings, root

cutting, and miscellaneous damage(each less than 1 %) were ofminor importance.

Deer ranked first among causes ofdamage to individual trees, brows-ing about one of every fiveDouglas-fir trees each year. Dur-ing the first 5 years after plant-ing, agents of damage were (indescending order of incidence):deer (19%), hares and rabbits(4%), elk (3%), grouse (3%),mountain beavers (1%), pocketgophers (1%), voles and woodrats(1%), domestic stock (1%), andother animals (1%).

Damage to Douglas-fir varied con-siderably by subregions through-out Oregon and Washington. Bud-ding by grouse (9%) and clippingby hares and mountain beavers(12%) were greatest in the CoastRange of Washington; browsingby deer and elk (11%) was leastin the Cascade Mountains ofWashington. On the 165 Douglas-fir plots in Oregon and Washing-ton, damage predominated on pri-vate forest lands with high sites,unburned slash, south aspects,gentle slopes, and medium eleva-tions of 1,100-1,500 feet(335-457 m).

During years 1-5, 15 percent ofponderosa pine trees were dam-aged each year on the 29 plots inOregon and Washington. Browsingagain was most common (10%),followed by clipping (4%), thenbarking, trampling, root cutting,and pulling of seedlings (each lessthan 1%). Other types of animaldamage were insignificant. Deerranked first (7%) among damaginganimals, followed by pocketgophers (3%), domestic stock(2%), hares (2%), and elk andporcupines (each less than 1%).Damage by other animals wasnegligible.

On the 45 selected plots exam-ined for 10 years, damage toDouglas-fir seedlings declinedyearly. Although browsing contin-ued as these stands developed,mean annual frequency of damage

1

dropped from 52 percent for thefirst 5 years to 41 percent forthe second 5 years. Some changesin damage types and agents wererelated to animal or plant succes-sion. For example, stem damageand budding decreased as standsdeveloped, and minor damage byDouglas squirrels, wood rats, andblack bears occurred for the firsttime on some of the older planta-tions.

impact on survivalPlanted seedlings die from a

variety of causes, especially duringthe first year after planting. Con-sequently, considerable mortalityunrelated to animal damage wasrecorded for both caged and un-caged Douglas-fir seedlings soonafter planting and throughout thefirst year.

After 5 years, survival on the 165Douglas-fir plots in Oregon andWashington averaged 71 percentof caged trees and 57 percent ofuncaged trees. We attributed this14 percent difference to animaldamage, chiefly clipping by hares,rabbits, and mountain beavers.Mean survival of caged and un-caged Douglas-fir trees was 77percent and 66 percent, respec-tively, in Washington and 68 per-cent and 53 percent, respectively,in Oregon. Mean survival washighest (85% and 71%) in theCoast Range of Washington andlowest (59% and 42%) in south-western Oregon.

Despite continued frequent injury,few additional caged and uncagedDouglas-fir trees died during years6 to 10 on the 45 selected plots.Evidently trees established for 5years can sustain repeated animaldamage by browsing, budding,and clipping with negligible effecton survival. For caged and un-caged pine seedlings, mean surviv-al decreased rapidly in the first 2years, falling to 71 and 49 per-cent, respectively, after 5 years.

impact on heightOn the 165 Douglas-fir plots inOregon and Washington, meanheight of caged trees exceededthat of uncaged trees by 12inches (30 cm) after 5 years.Caged trees averaged 50 inches(127 cm) and uncaged trees 38inches (97 cm), a 24-percentheight loss equivalent to about1.5 years' growth. Heights rangedfrom 58 inches (147 cm) in theWashington Coast Range to 29inches (74 cm) in the CascadeMountains of Oregon. UncagedDouglas-fir averaged 12 inches (30cm) taller in Washington than inOregon.

On 29 plots in Oregon, heights ofcaged and uncaged pines averaged23 and 18 inches (58 and 46cm), respectively, less than halfthose of Douglas-fir after 5 years.That 5 inch (13 cm) differencewas a proportional height loss of22 percent, similar to that forDouglas-fir.

On the Douglas-fir plots inOregon and Washington selectedfor 10-year study primarily be-cause of heavy animal damage,caged and uncaged trees averaged60 and 35 inches (152 and 89cm), respectively, 5 years afterplanting-a difference of 25inches (63 cm). Suppression ofheight continued, and the meandifference in height between thecaged and uncaged trees increaseduntil after the eighth year, whenit apparently stabilized near 42inches (107 cm).

After 10 years, heights of cagedand uncaged trees on these plotsaveraged 171 and 129 inches(434 and 328 cm), respectively, adifference of 42 inches (107 cm)or about 2 years' growth. Heightsof caged trees exceeded those ofuncaged trees by identicalamounts (42 in. or 107 cm) inboth states, despite the fact thattrees in Washington-by chanceon better sites-averaged 66inches (168 cm) taller at 10years.

2

introductionAnimal damage, the result of anyanimal activity that reduces ordelays total forest yield (Dimockand Black 1969), can determinethe success of reforestation inOregon and Washington (Moore1940, Lawrence 1958). West ofthe Cascade Mountains, youngDouglas-fir trees are injured bysmall rodents (such as voles andwoodrats), sooty grouse, moun-tain beavers, snowshoe hares,brush 'rabbits, deer, elk, livestock,and black bears. East of theCascade Mountains, ponderosapine are damaged by pocketgophers, snowshoe hares and jackrabbits, deer, elk, livestock, andporcupines.

To define the nature and signifi-cance of such damage by mam-mals and birds and to estimatethe economic consequences, theCooperative Animal Damage Sur-vey Committee undertook a10-year study. Douglas-fir andponderosa pine plantations estab-lished in Oregon and Washingtonin 1962 and 1963 were examinedannually for 5 to 10 years. Sitesregenerated by natural or artificialseeding, or with older age-classes,were excluded. All plantationsreflected reforestation practicesand stand-maintenance proceduresof private land owners and ofpublic forest-managing agenciesfrom 1963 to 1975.

When the survey began in1963-1964, reforestation in thePacific Northwest was character-ized by close planting, commonlyat 8- by 8-ft (2.4 x 2.4 m)intervals; by Douglas-fir seedlingstreated with Thiram animal repel-lent in the nursery bed; and byinfrequent use of herbicides instand maintenance. Reforestationwas mainly on old burns or onrecent clearcuttings where slashhad been broadcast burned. Di-rect seeding was also an impor-tant method of regeneration.

However, forest-management prac-tices are dynamic, responding tochanging economic conditions and

technology. Reforestation nowcalls for better planting stock,better handling and plantingmethods, wider spacing, lessbroadcast burning, and more in-tensive site preparation, includingconversion of brushfields. Westernhemlock and other conifer speciesless susceptible to animal damageare planted more frequently, andcontainerized stock has largelysupplanted direct seeding. Seed-lings increasingly are mechanicallyprotected, chiefly by "Vexar"tubing (Campbell and Evans1975b). Stand maintenance hasintensified with increased herbi-cide spraying for release, precom-mercial thinning, and control ofmountain beavers in precommer-cially thinned stands. For themost part, these practices havepromoted establishment andgrowth of seedlings, while re-ducing seedling, vulnerability toanimal damage. But these trendshave been partially offset by ex-tensive planting of small, contain-erized stock especially susceptibleto animal damage, by reduced useof Thiram (Anonymous 1975-76),and by more reforestation of con-verted brush fields with high po-tential for damage.

A preliminary report (Black et al.1969) described animal damageby type and agent, temporal andspatial distribution of damage,and impact of damage on survivaland growth of seedlings. This re-port summarizes the findings for194 sampling plots during fivegrowing seasons in the field. Inaddition, we describe the contin-ued occurrence of damage andthe growth response of 45Douglas-fir plots that were selec-ted from the original 165 Doug-las-fir plots and examined annual-ly for another 5 years. Historiesof individual plantations illustratethe succession and impact of var-ious damage agents.

The findings of this survey aremost applicable to stands estab-lished and maintained under con-ditions similar to those describedfor the sample plots. However,exposure! of conifer seedlings andsaplings to animal damage can beexpected to follow the patternsdescribed here; the impact ofdamage will vary with manage-ment practices.

3

procedures

Only newly established planta-tions of more than 50,000 Doug-las-fir or ponderosa and Jeffreypine trees were surveyed. Onesampling plot of 110 seedlingswas installed for each 500,000trees planted. To protect themfrom wildlife, 10 of the 110seedlings on each plot (usuallyevery 10th seedling) were cagedin cylinders, 3 feet (1 m) wideand 4 feet (1.2 m) tall, of 1-inch(2.5 cm) mesh wire. Stakes sup-ported the cages.

Plot location, marking, and exam-ination are detailed by Black etal. (1969). A total of 194sampling plots were installed inOregon (142 or 73%) andWashington. Of the total, 112were installed in 1963-64 (firstseries), and 82 were installed in1964-65 (second series). Of the194 plots, 163 (85%) were onpublic lands of the U.S. ForestService (73 plots), Bureau ofLand Management (54 plots),Oregon State Department of For-estry (26 plots), and WashingtonDepartment of Natural Resources(10 plots).

Species on the plots varied; 165plots (85%) were in Douglas-fir, 4plots (2%) in mixed Douglas-firand ponderosa pine, and 25 plots(13%) in ponderosa pine, Jeffreypine, or a mixture of both.

plot examinationThe first examination was at timeof planting (P), and the secondexamination was at bud burst inthe spring or summer after plant-ing (0). Thereafter, annual exam-inations during spring and sum-mer recorded 1 year's growthfrom bud burst to bud burst.

Personnel of the agency or com-pany installing a plot measuredheight immediately after planting;all other observations and meas-urements were made by a selectgroup of wildlife biologists andforesters under the direction ofthe Cooperative Animal DamageSurvey Committee. Height, re-corded to the nearest inch, wasmeasured from the ground to thebase of new terminal growth; cur-rent growth was not measured.

Animal-caused injuries to seedlingswere classified according to ter-minology in the illustrated Guideto Wildlife Feeding Injuries onConifers in the Pacific Northwest(Lawrence et al. 1961).

Data for individual trees on eachplot were recorded for each ob-servation period. Direct transcrip-tion in the field proved un-workable, but notes were re-corded in field notebooks andsubsequently transcribed ontooptical mark reader (OMR) formsso data could be automaticallyprocessed on magnetic tapes. Sim-plified programs summarized es-sential data. For plots observedmore than 5 years, data weretablulated with hand calculators.

continuedexaminationTo study the impact of animaldamage after establishment and tomonitor damage for a longer peri-od, we chose a subset of 51 plots(47 Douglas-fir and 4 ponderosapine) that-after 5 years-had ex-perienced heavy damage (chieflyby deer), a marked differencebetween heights of caged anduncaged trees, and above averagesurvival. About one-third of the51 plots were on private lands,proportionally more than in thetotal sample because damage oc-curred more frequently under pri-vate ownership.

Observation of 45 of the Douglas-fir plots, referred to herein asselected plots, was continuedthrough the 10th year; 30 ofthese were in Oregon (21 in thefirst series, 9 in the second), and15 in Washington (7 in the firstseries, 8 in the second). Slash hadbeen burned on 28 of these 45plots. Most were at low to medi-um elevation, 18 at elevations of1,000 to 1,500 feet (305-457 m),and only 2 were above 2,500 feet(762 m). This selected samplealso was skewed to higher siteclasses; 19 plots were classifiedsite 1 or 2 for Douglas-fir, 24classified as site 3, and 2 classi-fied as site 4. No site 5 classeswere included.

In addition, one Douglas-fir plotin Oregon and one in Washingtonwere observed through the 8thyear, and four ponderosa pineplots in Oregon were observedthrough the 8th to 10th years.However, findings are summarizedonly for the selected plots.Individual histories of some selec-ted plots and some of the othersix plots are cited to showsuccession of animal damage andthe effect of damage by variousanimals.

5

douglas-fir plots: years 1-5

animal damageDamage type was, of course,closely related to damage agent;for example, injury by deer cor-related with browsing. Mean fre-quency of damage for all Doug-las-fir plots peaked at 32 percentduring the first year (third exam-ination), remained at about thatlevel for 2 more years, then de-creased in years 4 and 5. Stemdamage peaked at 29 percent thefirst year, then decreased gradual-ly (Fig. 1).

Browsing, which averaged 21 per-cent each year, was the mostcommon type of damage onDouglas-fir plots in all subregions

60

40

20 7C

w

00

of both states (Tables 1-3). Otherdamage was clipping (6%), bud-ding (3%), and trampling, barking,pulling of seedlings, root cutting,and miscellany (each less than1%). Deer (19%) ranked first as adamage agent, followed by haresand rabbits (4%), elk (3%), grouse(3%), mountain beavers (1%), andpocket gophers, microtine ro-dents, domestic stock, and miscel-laneous agents (each less than1%). On the average, more thanone of every five live uncagedtrees were browsed, mainly bydeer. Porcupine damage was notrecorded on any of the 165Douglas-fir plots during the first5 years of the study.

0

stem damage--'

P O 1 2 3years

4 5

Figure 1.

Mean percent of uncaged Douglas-fir trees damaged by animals on165 plots in Oregon and Washing-ton, years 1-5 after planting.

Table 1.

ANIMAL-DAMAGED DOUGLAS-FIR PLOTS, YEARS 1-5 AFTERPLANTING.(mean annual percent)

OREGON WASHINGTONCoast Cascade South- Coast Cascade BOTHRange Mountains west All Range Mountains All STATES

Damage (49)a (24) (33) (116) (24) (25) (49) (165)

TYPEBarking 0.12 0.16 0.08 0.12 0.32 0.33 0.32 0.18Browsing

Overall 24.38 24.00 23.08 23.86 23.44 11.36 17.28 21.90Stem 20.30 20.41 20.75 20.46 15.93 8.41 12.09 17.98

Budding b

Overall 0.22 3.23 2.34 1.71 8.74 1.89 5.25 2.76Stem 0.01 0.60 0.07 0.20 3.18 1.43 2.28 0.82

ClippingOverall 6.21 5.50 1.67 4.71 11.55 4.66 8.04 5.70Stem 3.41 3.22 1.08 2.69 4.02 2.68 3.33 2.88

Root cutting 0.07 0.02 0.00 0.04 0.01 0.00 0.00 0.03Pulling 0.10 0.01 0.22 0.11 0.03 0.01 0.02 0.08-Trampling 0.23 0.27 0.21 0.23 0.37 0.13 0.25 0.24Other 0.03 0.04 0.01 0.03 0.17 0.11 0.14 0.16-All Damage 30.61 32.20 26.99 30.05 39.08 17.81 28.22 29.51Stem Damage 23.98 24.42 22.20 23.60 23.44 12.72 17.97 21.93

AGENTDeer 21.82 24.26 19.31 21.32 14.38 10.62 12.46 19.04Domestic stock 0.01 0.02 0.01 0.01 0.02 0.00 0.01 0.01Elk 2.71 0.03 4.03 2.30 10.65 1.27 5.87 3.36Gopher 0.10 0.03 0.01 0.06 0.01 0.00 0.00 0.04Grouseb 0.22 3.25 2.39 1.72 8.78 1.97 5.30 2.79Hare 5.40 3.90 1.31 3.80 3.70 2.64 5.61 4.33Mountain beaver 0.82 1.18 0.37 0.80 2.88 0.59 1.71 1.07P1icrotine 0.01 0.01 0.03 0.02 0.07 0.05 0.06 0.03Porcupine 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00Other 0.03 0.40 0.00 0.13 0.08 1.42 0.76 0.32

a Numbers in parentheses are number of plots.

bFrequency of overall budding and of grouse damage should be identical becausegrouse are the only agents. Small differences are errors.

Table 2.

DOUGLAS-FIR TREES DAMAGED BY ANIMALS, YEARS 1-5

AFTER PLANTING.a(mean percent)

Year

Damage Ob 1 2 3 4 5

TYPEBarking 0.00 0.12 0.12 0.17 0.32 0.23Browsing

Overall 4.92 25.35 23.52 26.31 20.00 16.13Stem 4.46 23.44 19.28 20.58 15.69 11.95

BuddingOveralls 0.27 1.23 2.79 3.27 3.77 3.22Stem 0.27 1.23 2.79 0.00 0.00 0.00

ClippingOverall 1.10 5.90 6.19 6.47 4.52 5.92Stem 0.93 4.37 3.33 2.57 2.04 2.01

Root cutting 0.00 0.00 0.01 0.02 0.02 0.08Pulling 0.24 0.14 0.03 0.00 0.00 0.03Trampling 0.19 0.24 0.26 0.21 0.29 0.09Other 0.05 0.10 0.11 0.02 0.02 0.0

All Damage 6.59 32.15 31.82 34.45 27.00 24.41Stem Damage 5.99 29.15 25.41 23.41 18.04 14.30

AGENTDeer 4.15 22.05 19.84 24.12 16.68 14.14Domestic stock 0.02 0.00 0.02. 0.01 0.01 0.01Elk 1.01 3.64 3.95 3.29 3.82 2.19Gopher 0.01 0.01 0.03 0.05 0.05 0.06Grousec 0.28 1.23 2.86 3.30 3.77 3.27Hare 0.75 4.39 5.17 4.83 3.23 4.53Mountain beaver 0.38 1.01 0.72 1.47 1.03 1.09Microtine 0.00 0.04 0.09 0.01 0.00 0.01Porcupine 0.00 0.00 0.00 0.00 0.00 0.00Other 0.02 0.53 0.23 0.25 0.24 0.34

a Based on 165 plots.

bFirst bud burst about 4 months after planting.cFrequency of bud burst and grouse damage should be identical because grouseare the only agents. Small differences are errors.

plotThe percent of plots, rather thantrees, having animal damage is

summarized by type and agentfor each examination and for thesum of all examinations (Tables 3and 18A). Because individualplots may not have been damagedin some years, frequency in a

given examination is always lowerthan the combined frequency.For example, barking injuries oc-curred on only 5 to 9 percent ofall Douglas-fir plots during annualexaminations, but occurred oneor more times on 25 percent ofthe plots for all examinations.Animal damage was recorded onall Douglas-fir plots at least once

during the study, but on onlytwo-thirds of all plots during thefirst examination. Animal damageoccurred on more than 90 per-cent of all plots each year afterthe first, except the fifth yearwhen only 84 percent of plotswere damaged.

Damage types were browsing(99%), clipping (80%), budding(50%), trampling (35%), and bark-ing (25%). Barking and buddingoccurred on proportionally moreplots in Washington than inOregon; differences were smallerfor other types of damage toplots in the two states (Table18A). In all, budding occurred on

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Table 3.

DOUGLAS-FIR PLOTS DAMAGED BY ANIMALS, YEARS 1-5 AFTERPLANTING.a(mean annual and aggregate percent)

Year

Damage 0b 1 2 3 4 1-5

TYPEBarking 0.00 6.67 5.45 7.27 6.67 9.09 25.45Browsing

Overall 55.76 86.67 91.52 88.48 78.79 72.12 99.39Stem 51.52 85.45 88.48 85.45 76.36 63.03 98.18

BuddingOverallc 4.24 13.33 20.61 26.06 29.09 23.64 49.70Stem 4.24 13.33 20.61 0.00 0.00 0.00 25.45

ClippingOverall 24.85 55.76 50.30 46.06 42.42 43.64 80.00Stem 23.03 50.30 41.21 32.12 26.06 27.27 73.94

Root cutting 0.00 0.00 0.61 1.21 0.61 2.42 3.64Pulling 4.85 6.67 1.82 0.00 0.00 0.61 11.52Trampling 7.27 10.30 13.94 10.30 6.67 3.64 35.15Other 2.42 6.67 1.82 1.82 1.21 1.21 12.73

All Damage 66.67 92.73 95.15 95.76 90.30 84.24 100.00Stem Damage 64.24 92.12 93.33 92.12 81.21 75.76 99.39

AGENTDeer 54.55 80.00 84.24 81.82 69.09 66.67 96.36Domestic stock 0.61 0.00 1.21 0.61 0.61 0.61 3.64Elk 4.85 10.91 13.33 12.12 15.15 13.33 21.21Gopher 0.61 0.61 0.61 0.61 1.21 1.82 3.54Grouses 4.24 13.33 20.61 26.67 29.09 24.85 50.91Hare 19.39 47.88 40.61 41.21 30.91 30.91 75.15Mountain beaver 7.88 10.91 11.52 13.33 13.33 10.30 25.45Microtine 0.00 1.82 3.03 1.21 0.00 0.61 6.06Porcupine 0.00 0.00 0.00 0.00 0.00 0.00 0.00Other 1.21 4.24 3.03 1.82 1.82 4.85 10.91


bFirst bud burst about 4 months after planting.cFrequency of overall budding and of grouse damage should be identical becausegrouse are the only agents. Small differences are errors.

half or more of all plots in eachsubregion except the OregonCoast Range.

All 165 Douglas-fir plots in bothstates were browsed except forone plot in the Oregon CascadeMountains. Frequency data forthat plot may have been affectedby poor survival; only 25 percentof uncaged trees survived to thefirst year, and only 7 percent tothe fifth year. Clipping occurredon 80 percent of the 165 plots,budding on 50 percent; all othertypes of damage occurred on lessthan 50 percent of the plots.Root cutting and pulling of seed-lings were less frequent-on 6

plots (4%) and 19 plots (12%),respectively.

Ranked by plot frequency, dam-age agents were deer (96%), haresand rabbits (75%), grouse (51%),mountain beavers (25%), elk(21%), microtine rodents (6%),pocket gophers (4%), domesticstock (4%), and miscellaneous ani-mals (11%). Damage by gophersand domestic stock was uncom-mon in all regions, and none wasrecorded on plots in the CascadeMountains of Washington. Neitherporcupines nor bears damagedany of the 165 Douglas-fir plotsduring the first 5 years of thestudy.

9

5

distributionDistribution of damage variedconsiderably by subregions onboth series of plots. Budding bygrouse (9%) and clipping by haresand mountain beavers (11%) weregreatest in the Coast Range ofWashington, and browsing by deerand elk (11%) was lowest in theCascade Mountains of Washington(Table 1).

The highest frequency of damage(39%), recorded on the 24 plotsin the Coast Range of Washing-ton, was a combination of brows-ing, budding, and clipping of thesame trees. The lowest frequency(18%) was recorded on the 25plots in the Cascade Mountains ofWashington.

Browsing, especially stem brows-ing, occurred less in Washington(17%) than in Oregon (24%), butbudding and clipping of lateralswere more frequent on plots inWashington (5%) than in Oregon(2%). Stem clipping was compar-able in both states. Deer browsedfewer trees in Washington (12%)than in Oregon (22%), althoughinjuries by elk, grouse, hares, andmountain beavers totaled higherin Washington (18%) than inOregon (9%).

minor typesTrampling, barking, pulling ofseedlings, root cutting, and otherinjuries occurred on less than 1

percent of Douglas-fir trees eachyear. Trampling was mainly bydeer, elk, and domestic livestock;barking was mainly by rodents,lagomorphs, and big game (antlerrubbing). Deer and elk usuallypulled seedlings only in the firstand second years after planting.Root cutting by pocket gophersand mountain beavers was infre-quent, and miscellaneous injurywas insignificant.

survivalMean survival of caged and un-caged trees on the 165 Douglas-fir plots in Oregon and Washing-ton is summarized by state andsubregion in Table 4. Missing anddead seedlings (damaged and un-damaged by animals) were in-cluded in mortality.

Early mortality between plantingand bud burst was unrelated toanimal damage. Mortality from allcauses peaked during the firstyear after planting (Fig. 2) butdeclined rapidly thereafter, espe-cially on plots in Washington.After 5 years, survival on theDouglas-fir plots in Oregon andWashington averaged 71 percentof caged trees and 57 percent ofuncaged trees-a highly significant(P>0.01) difference chiefly dueto animals. Thus, about one-third(33%) of total uncaged mortality(14% divided by the 43% total)was animal related. This propor-tion was consistent, ranging from32 to 35 percent for years 1 to5.

Survival of both caged and un-caged trees (Fig. 2) was higher inWashington (77% and 66%) thanin Oregon (68% and 53%). Meansurvival was highest in the Wash-ington Coast Range (85% ofcaged and 71% of uncaged treesafter 5 years) and lowest insouthwestern Oregon (59% ofcaged and 42% of uncaged trees).

Mortality differed between plant-ing series. Trees planted in thefirst series survived better in eachstate than did trees planted inthe second series (Figs. 2B,C).These differences were greatest inOregon. There mean survival ofcaged Douglas-fir trees in the firstseries of 70 plots was 71 percent;it was 64 percent in the secondseries of 46 plots. Survival ofDouglas-fir trees in Washingtonwas 4 percent higher in the firstseries of 24 plots than in thesecond series of 25 plots. Thesedifferences are mainly attributable

10

Table 4

SURVIVALa OF CAGED AND UNCAGED DOUGLAS-FIR TREES,YEARS 1-5 AFTER PLANTING.b(mean percent)

Year

Location PlotsTreat-ment

Plant-ing 0c 1 2 3 4 5

OREGON

Coast Range 49 Caged 100.00 87.30 82.59 81.16 78.10 76.90 75.47Uncaged 99.94 86.72 74.23 70.27 64.82 62.14 60.29

CascadeMountains 34 Caged 100.00 81.55 72.19 71.04 69.57 68.10 67.22

Uncaged 100.00 79.17 63.69 59.07 55.87 53.24 51.92Southwest 33 Caged 100.00 89.10 72.16 67.31 65.19 60.98 58.88

Uncaged 100.00 83.15 53.99 48.51 45.96 43.56 41.83Total 116 Caged 100.00 86.12 76.58 74.26 71.93 69.79 68.33

Uncaged 99.97 83.49 65.38 60.79 56.83 54.25 52.59

WASHINGTONCoast Range 24 Caged 100.00 95.83 91.25 89.17 88.33 86.67 85.00

Uncaged 100 00 93 42 81 66 76 70 73 66 5471 5470. . . . . . .


Uncaged 100.00 88.64 69.68 65.64 63.86 62.08 61.44

Total 49 Caged 100.00 92.65 83.06 80.24 79.42 78.61 77.38Uncaged 100.00 90.98 75.55 71.05 68.57 66.71 65.90

BOTH STATESTotal 165 Caged 100.00 88.06 78.50 76.03 74.16 72.41 71.02

Uncaged 99.98 85.71 68.40 63.84 60.32 57.95 56.54

aMissing trees are included in mortality regardless of cause.bBased on 165 plots.

cFirst bud burst about 4 months after planting.

to the poor growing conditions inspring and summer of 1965(Black et al. 1969).

On the selected sample, an aver-age of 85 percent of caged treesand 64 percent of uncaged treessurvived, a better rate due mainlyto removal of all plots with poorsurvival.

growthMean height of all caged anduncaged Douglas-fir trees is shownin Figure 3A and Table 5. Alltrees grew more in Washingtonthan in Oregon (Fig. 3B). OnWashington plots, height averaged58 inches (147 cm) for cagedtrees, and 46 inches (117 cm) foruncaged trees, a difference of 11inches (28 cm). In Oregon heightaveraged 46 inches (117 cm) for

caged trees and 34 inches (86cm) for uncaged trees, a differ-ence of 12 inches (30 cm). Onall Douglas-fir plots after 5 years,mean height was 50 inches (127cm) for caged trees and 38 inches(97 cm) for uncaged trees-a 24percent height loss equivalent toabout 1.5 years' growth.

In the Washington Coast Range,height at 5 years averaged 74inches (188 cm) for caged treesand 58 inches (147 cm) for un-caged trees. In the Oregon Cas-cade Mountains, mean height at 5years was substantially higher, 40inches (102 cm) for caged treesand 29 inches (74 cm) for un-caged trees. Tree growth in south-western Oregon and in the Cas-cade Mountains of both stateswas much lower than in theCoast Range of both states.

On the 30 selected plots inOregon, caged trees were taller,51 inches (130 cm), than in thetotal sample; uncaged trees wereshorter, 26 inches (66 cm).Height variation between trees inboth planting series was minor, asit was on the 15 selected Doug-las-fir plots in Washington at 5years. Although caged trees weretaller in the first than in thesecond series, mean height of un-caged trees differed negligibly.Both caged and uncaged trees onthe Washington plots were tallerthan on Oregon plots at 5 years.Uncaged trees in Washington werealmost twice as tall as uncagedtrees in Oregon, 51 inches (130cm) and 26 inches (66 cm), re-spectively.

11

a

>D

100

80

100

cageWashington

Oregon

60

40

20

0100

80

60

40

20

uncageuncaged

80 ........ series

60

40

A

::. caged

N.......... ........... ..... ....

uncaged

20

0100

80

60

40

20

B

n

cagedO 0

cage

0

puncaged

C D

0P O 1 2 3 4 5 P 01

years1 2 3 4 5

Figure 2.

Mean survival of Douglas-fir trees,years 1-5 after planting. (A) 116plots in Oregon, 49 plots inWashington. (B) Both series inOregon. (C) Both series in Wash-ington. (D) 165 plots in Oregonand Washington.

00

series1

8

12

Figure 3.

Mean height of Douglas-fir trees,years 1-5 after planting. (A) 165plots in Oregon and Washington.(B) 116 plots in Oregon, 49 plotsin Washington.

13

Table 5.

MEAN HEIGHT OF CAGED AND UNCAGED DOUGLAS-FIR TREES,YEARS 1-5 AFTER PLANTING.a(inches)

Year

Location PlotsTreat-ment

Plant-ina Ob 1 2 3 4 5

OREGONCoast Range 49 Caged 9.33 9.14 11.03 16.47 25.63 38.13 53.33

Uncaged 9.18 8.97 9.25 12.28 18.23 27.15 39.49


Uncaged 8.23 8.19 8.38 10.39 14.31 20.73 28.77

Southwest 33 Caged 7.81 7.71 9.13 13.13 20.33 30.39 41.92

Uncaged 7.93 7.89 8.37 10.58 14.76 21.50 30.86

Total 116 Caged 8.62 8.48 10.10 14.62 22.48 33.29 46.09

Uncaged 8.55 8.43 8.75 11.26 16.12 23.85 33.91

WASHINGTONCoast Range 24 Caged 12.37 12.39 14.37 22.44 35.61 53.15 74.34

Uncaged 12.28 12.28 13.05 17.41 26.42 39.80 57.86


Uncaged 7.79 7.71 8.31 11.20 16.88 25.15 35.25

Total 49 Caged 10.12 10.17 11.81 18.09 28.57 41.92 57.59

Uncaged 9.99 9.95 10.63 14.24 21.55 32.33 46.32

BOTH STATESTotal 165 Caged 9.06 8.98 10.61 15.67 24.33 35.91 49.61

Uncaged 8.98 8.88 9.32 12.16 17.77 26.43 37.71

aBased on 165 plots.

bFirst bud burst about 4 months after planting.

damage andplot featuresAnimal damage is related to plotfeatures such as ownership, slashtreatment, aspect, slope, site qual-ity, elevation, and stock class(Tables 1A-18A). Because none ofthese features is independent, oc-currence of damage is similarlyrelated to several features. Forexample, site quality tends to belower as elevation or slope in-creases.

ownershipBrowsing by deer and elk wasonly about half as frequent onU.S. Forest Service lands (11%)as on other ownerships (20-25%)(Table 1A). Elk frequently dam-aged lands managed by theOregon State Department of For-estry, but grouse budding wasleast frequent there. In Oregon,private lands led in occurrence ofdamage by all agents except elk.Budding by grouse and clippinginjuries, chiefly by hares, weremost frequent on private lands inWashington. Private lands led inoccurrence of damage of all typesin both states (Table 2A and

14

3A). Damage to stems and lat-erals averaged 44 percent on pri-vate lands, 19 to 37 percent onpublic lands.

Distribution of damage related toownerships differed most withinregions. The mean for deerbrowsing of Douglas-fir plots inthe Oregon Cascades was onlyabout 6 percent on U.S. ForestService plots, but 34 percent onprivate plots and 40 percent onBureau of Land Managementplots. Of the 49 Douglas-fir plotsin Washington, only 8 percent oftrees were browsed on the 24U.S. Forest Service plots, butmore than 25 percent werebrowsed on both the 10 plots ofthe Washington Department ofNatural Resources and the 15private plots. One percent oftrees were budded on U.S. ForestService plots, but 13 percent onplots on private lands. Four per-cent of trees were clipped onU.S. Forest Service plots, 10 per-cent on lands of the Departmentof Natural Resources, and 14 per-cent on private lands. These dif-ferences between private and pub-lic lands probably reflect differ-ences in environment and manage-ment history.

slash treatmentOn the average, unburned plotswere damaged more often (34%)than burned plots (27%) (Table4A). Principal differences werethe higher incidence of buddingand clipping, but damage by elk,hares, mountain beavers, andgrouse also was more frequent.

In Oregon, occurrence of animaldamage was comparable on slash-burned and unburned plots (Table4A), but unburned plots inWashington experienced morebrowsing, budding, and clipping.Mean annual occurrence of deerbrowsing was similar on burnedand unburned plots, but damageby elk, grouse, and hares wasmuch higher on unburned plots.

aspectAspect influenced damage onDouglas-fir plots (Tables 5A, 6A,and 7A). Damage was greatest onplots with southerly aspectswhere most browsing by deer andbudding by grouse occurred. Onlyminor differences in mean annualfrequency of damage, includingbrowsing and budding, werefound among other aspects. But,on the average, more browsing byelk and clipping by hares oc-curred on level plots with nopredominant aspect.

This overall pattern was similar tothat on Douglas-fir plots inOregon (Table 6A), although clip-ping by hares was more frequenton other aspects. On the Douglas-fir plots in Washington, meanoccurrence of clipping by hareswas greatest on level plots (Table7A). Deer browsing and grousebudding occurred most frequentlyon east and south aspects; elkbrowsing was recorded most oftenon south and west aspects.

slopeMean annual frequency of animaldamage is related to slope inTables 8A, 9A, and 10A. Damageof all types was most frequent ongentle slopes (6%-25%), althoughclipping damage in Oregon oc-curred with about the same fre-quency on flat, gentle, moderate,and steep slopes. In both states,damage by elk and mountain bea-vers was high on both level andsteep terrain; hare damage wasconsistently highest on level andgently sloped terrain.

site qualityOf the 165 Douglas-fir plots, 88plots were classified site 3 forDouglas-fir, 46 were site 1 or 2,and 31 were site 4 or 5 (Table11A). All principal types of ani-mal damage (browsing, clipping,and budding) occurred most fre-quently on the highest sites andleast frequently on the lowestsites. Agents also followed this

15

pattern, except that deer damagewas highest on intermediate sites(site 3). The relationship was in-consistent on Douglas-fir plots inOregon (Table 12A), althoughsites 3 or better were damagedmore frequently than sites 4 and5. On Douglas-fir plots in Wash-ington, however, damage of alltypes and by all agents predom-inated on site classes 1 and 2(Table 13A). An average of 51percent of trees on plots on highsites were injured each year. Only14 percent of trees were injuredon low-site plots. Notably, elk,grouse, and hares substantiallydamaged high-site plots.

elevationThe relation of annual frequencyof damage by type, agent, andelevation is shown for all Doug-las-fir plots in Oregon and Wash-ington in Tables 14A, 15A, and16A. Most plots (130 of 165)were located at low to mediumelevations, 600 to 2,500 feet(183-762 m), where damage of alltypes was most frequent. Brows-ing was most frequent on plots at1,100 to 1,500 feet (335-457 m),budding on plots at 2,100 to2,500 feet (640-762 m), and clip-ping on plots at 0 to 500 feet(0-152 m). Deer and elk were themost frequent agents of damageat 1,100 to 1,500 feet (335-457m), grouse at 2,100 to 2,500 feet(640-762 m), and hares at 0 to500 feet (0-152 m). In Oregonand Washington, all types of dam-age were most frequent on plotsat 1,100 to 1,500 feet (335-457m).

stock classMost Douglas-fir plots wereplanted with 2-0 stock (Table17A). The three sizes of stockmost commonly planted (2-0, 3-0,and 2-1) sustained comparabledamage, although deer damagewas highest on 2-0 stock anddamage by other animals washighest on the remainder. Damageappeared more related to locationthan to stock size. The smallnumber of plots of some stock

classes in each subregion and theplanting of older stock on siteswith brush competition and highdamage potential may have influ-enced the findings.

tree ageand damageoccurrencebarkingMost of the negligible amount ofbarking that was recorded oc-curred on seedlings 3 to 5 yearsafter planting.

browsingBrowsing was most frequent inthe first, second, and third years,and declined markedly in thefourth and fifth years. Douglas-firplots in the Coast Range ofOregon were browsed most fre-quently (Fig. 4A). Althoughbrowsing was not systematicallyrecorded during the dormant andgrowing seasons, most damage oc-curred on new-shoot growth inthe spring.

buddingBudding by grouse (3%) was sur-prisingly common and widespread,especially in Washington. Itranked third among damagetypes, and grouse ranked fourthamong damage agents (Table 1).Grouse budding occurred on 51percent of all Douglas-fir plots(Table 18A) and remained fairlyconstant throughout the 5-yearperiod; however, terminal budsgenerally were affected only dur-ing years 1 and 2 (Tables 2-3).

clippingClipping on all Douglas-fir plots(Tables 2-3) changed little fromyear to year, although stem clip-ping peaked the year after plant-ing and declined as trees matured.Figure 4B illustrates heightgrowth and occurrence of stemclipping, mainly by hares, onDouglas-fir plots in the CoastRange of Washington where fre-quency of clipping was highest.

16

Figure 4.

Mean percent of stem damage touncaged Douglas-fir trees in rela-tion to mean height of trees,years 1-5 after planting. (A) Treesbrowsed by deer on 49 plots inthe Oregon Coast Range. (B)Trees clipped, chiefly by hares,on 24 plots in the WashingtonCoast Range.

17

pine plots: years 1-5

animal damageAnimal damage of some type oc-curred on all pine plots (Table19A). Browsing occurred duringthe 5-year period on all but oneof the plots, clipping on three-fourths of the plots, and all otherdamage types on less than half ofthe plots.

However, mean annual frequencyof damage of all types was only15 percent the pine plots (Table6). Browsing (10%) was the mostcommon type (as on Douglas-firplots), followed by clipping (4%),then barking, trampling, root cut-ting, and pulling of seedlings(each less than 1%). Mean fre-quency of damage was highest inthe first and second years, thenstabilized at about 6 percent an-nually on uncaged trees (Fig. 5).

Trees were damaged by deer(7%); pocket gophers (3%);domestic stock, chiefly cattle(3%); hares or rabbits (2%); elk(<1%); and porcupines (<1%).Few trees were injured by grouse,and damage by other agents wasnegligible. No trees were damagedby mountain beavers or microtinerodents.

PINE TREES DAMAGED BYANIMALS, YEARS 1-5 AFTERPLANTING.(mean annual percent)

Damage Both Statesa

TYPEBarking 0.60Browsing

Overall 9.82Stem 8.44

BuddingOverall 0.01Stem 0.00

ClippingOverall 4.01Stem 3.49

Root cutting 0.49Pulling 0.16Trampling 0.53Other 0.01

All Damage 15.10Stem Damage 13.20

AGENTDeer 7.18Domestic stock 2.46Elk 0.71Gopher 2.56Grouse 0.01Hare 1.57Mountain beaver 0.00Microtine 0.00Porcupine 0.70Other 0.07

aBased on 29 plots.

all damage

stem damage'r x

P O 1 2 3 4 5

years

Figure 5.

Mean percent of pine trees dam-aged by animals on 19 plots inOregon, years 1-5 after planting.

18

Table

n

Deer damaged all but one plotduring the 5-year period. Hares(or rabbits), domestic stock, andpocket gophers each caused dam-age on about half of the plots.Other agents damaged only a fewplots.

survivalMean survival of caged and un-caged seedlings on all 29 pineplots decreased rapidly in thefirst 2 years after planting andmore gradually thereafter (Fig.6A). After 5 years, the differencein mean survival between cagedand uncaged trees (Table 7) was22 percent (caged trees-71%, un-caged trees-49%). If this differ-ence is attributed to animal dam-age, 43 percent of all mortalitywas animal related.

growthMean height of all caged anduncaged pine seedlings at 5 yearswas only 23 and 18 inches (58and 46 cm), respectively (Table7, Fig. 6B). Although the differ-ence was only 5 inches (13 cm),the proportional height loss of 22percent was similar to that forDouglas-fir in western Oregon andWashington.

Table 7.

100

80

D

60

>LD

40

20

0

a-srn

s

20

0P0 1 2 3 4

years

SURVIVALa AND HEIGHT OF CAGED AND UNCAGED TREES,YEARS 1-5 AFTER PLANTING.b

Year

Planting Oc 1 2 3 4 5

SURVIVAL (%)Caged 100.00 95.52 84.14 79.00 75.20 73.48 70.72Uncaged 100.00 95.00 69.79 59.86 54.86 50.89 48.62

HEIGHT (in.)Caged 4.61 4.55 5.42 7.84 11.48 16.79 23.38Uncaged 4.57 4.50 4.95 6.49 8.99 13.21 18.37

aMissing trees are included in mortality regardless of cause.bBased on 29 plots.

cFirst bud burst about 4 months after planting.

Figure 6.

Mean survival (A) and height (B)of pine trees on 29 plots inOregon and Washington, years 1-5after planting.

19

5

selected douglas-fir plots: year

animal damageOn 45 selected Douglas-fir plots,browsing was the principal typeof damage, followed by clipping,budding, barking, and miscel-laneous injury (Table 8, Fig. 7).Most damage on the selectedplots was caused by deer, fol-lowed by hares, elk, grouse, andmountain beavers. Incidental dam-age was attributed to Douglassquirrels, wood rats, black bears,and band-tailed pigeons-damageagents not identified during thefirst 5 years of the survey.

Table 8.

Even on these plots, selected be-cause of heavy damage duringyears 1 to 5, damage continuedto decrease as stands developed.The percentage of plots damagedduring the first 5 years was 52percent, for the second 5 years41 percent (Fig. 7). The differ-ence between the first and second5 years was greater on the 30plots in Oregon (50% and 36%)than for the 15 plots in Washing-ton (55% and 52%) (Table 6).

DOUGLAS-FIR TREES DAMAGED BY ANIMALS ON SELECTED PLOTS, YEARS 1-10 AFTERPLANTING.a(mean annual and aggregate percent)

Years

Damage 0 1 2 3 4 5 6 7 8 9 10 0-5 6-10

TYPEBarking 0.00 0.11 0.18 0.09 0.23 0.31 0.24 0.42 0.35 0.39 0.40 0.17 0.36Browsing

Overall 12.80 60.60 41.47 52.08 41.72 34.59 36.27 28.86 22.05 24.36 22.25 45.64 26.76

Stem 12.22 56.30 33.21 40.18 32.06 26.10 20.07 12.53 7.94 7.22 4.91 37.54 10.53Budding 0.91 3.77 6.33 6.45 6.81 3.05 1.53 1.77 1.14 0.39 0.48 5.13 1.06Clipping

Overallc 1.47 10.04 8.08 8.44 7.05 7.15 12.41 14.19 11.42 12.02 10.46 7.93 12.24Stem 1.37 7.32 3.61 2.93 3.22 2.45 1.81 2.37 1.36 1.76 1.36 3.94 1.73

Root cutting 0.00 0.00 0.03 0.00 0.00 0.00 0.00 0.00 0.00 0.21 0.00 0.01 0.04Pulling 0.79 0.40 0.03 0.00 0.00 0.00 0.00 0.00 0.00 0.03 0.00 0.24 0.01

Trampling 0.48 0.25 0.27 0.32 0.37 0.07 0.06 0.07 0.03 0.10 0.03 0.33 0.06Other 0.16 0.11 0.00 0.06 0.03 0.00 0.62 1.91 0.60 2.16 0.96 0.07 1.25

All Damage 15.99 72.93 54.45 62.87 51.42 42.77 48.05 46.14 35.58 36.17 34.89 56.37 40.17Stem Damage 15.36 67.29 42.33 43.41 35.66 28.84 22.52 15.51 10.02 11.48 6.98 43.69 13.30

AGENTDeer 9.64 50.35 31.55 48.23 34.87 28.98 28.50 25.06 18.94 18.37 18.33 38.20 21.84Domestic stock 0.07 0.00 0.00 0.03 0.00 0.00 0.00 0.00 0.53 0.50 0.00 0.02 0.21Elk 3.79 10.67 10.19 7.10 8.32 5.96 8.42 7.13 2.93 4.40 3.88 8.64 5.35Gopher 0.00 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.25 0.00 0.00 0.05cGrouse 0.94 3.74 7.16 6.35 6.92 3.05 1.53 1.77 1.14 0.39 0.48 5.28 1.06Hare 0.33 7.18 6.58 6.91 4.24 5.08 9.86 9.76 9.66 9.27 8.24 5.69 9.36Mountain beaver 1.25 2.83 1.49 1.59 2.67 1.92 2.23 2.34 1.32 1.58 1.66 2.20 1.83Other 0.02 0.05 0.15 0.09 0.03 0.07 0.80 2.87 0.93 2.85 1.62 0.08 1.81


bFirst bud burst about 4 months after planting.cFrequency of overall budding and grouse damage should be identical because grousedifferences are errors.

are the only agents. Small

20

1-10

80

40

20

0PO 2

all damage11

11

stem damage

n0 n

n

4 6 8 10

years

Figure 7.

Mean percent of uncaged Douglas-fir trees damaged by animals on45 selected plots in Oregon andWashington, years 1-10 afterplanting.

survivalMortality was low in years 6 to10; hence the difference in sur-vival between caged trees (83%)and uncaged trees (60%) was thesame (23%) after 10 years asafter 5 years (Table 9, Fig. 8).During the first 5 years, browsingand budding damage affectedheight growth but had little im-pact on survival, and 10-year ob-servations further showed that es-tablished trees (5 years and older)can sustain repeated animal dam-age (browsing, budding, and clip-ping) without serious effect. Mor-tality that did occur (about 2%to caged and about 4% to

uncaged trees in 5 years) wasfrom stem clipping by mountainbeavers and hares, mechanicaldamage such as windthrow (frompoor planting procedures), or sup-pression by competing vegetation.

Mean survival was better on plotsin Washington than in Oregon-90percent of caged trees after 5 and10 years, 74 and 69 percent ofuncaged trees after 5 and 10years, respectively. Survival forcaged trees on the 30 plots inOregon averaged about 83 percentafter 5 years and 79 percent after10 years. Survival for uncagedtrees was 58 percent after 5 yearsand 55 percent after 10 years.

21

Table 9.

SURVIVAL OF CAGED AND UNCAGED DOUGLAS-FIR TREES ON SELECTEDPLOTS, YEARS 1-10 AFTER PLANTING.(mean percent)

Year

Treatmenta 1 2 3 4 5 6 7 8 9 10

OREGON (30)Caged Mean 91.67 87.00 86.00 84.00 83.33 82.67 82.33 82.33 80.67 80.00 79.33

S.D. 11.47 14.66 15.67 15.45 14.93 14.84 14.55 14.55 17.21 17.62 17.21

Uncaged Mean 88.93 73.33 68.13 63.40 59.93 58.33 57.33 56.83 56.30 55.40 54.93

S.D. 10.36 14.43 15.85 16.94 17.11 18.03 17.92 18.41 18.68 19.25 19.79

WASHINGTON (15)Caged Mean 99.33 96.67 94.67 92.67 92.67 90.00 90.00 90.00 90.00 90.00 90.00

S.D. 2.58 8.16 8.34 9.61 9.61 13.09 13.09 13.09 13.09 13.09 13.09

Uncaged Mean 96.20 85.40 81.67 77.87 75.20 74.07 73.33 72.67 72.67 69.67 69.27

S.D. 4.30 8.47 12.64 16.00 17.44 18.13 18.79 19.52 19.71 21.00 20.89

BOTH STATES (45)Caged Mean 94.22 90.22 88.89 86.89 86.44 85.11 84.89 84.89 83.78 83.33 82.89

S.D. 10.11 13.57 14.18 14.27 14.01 14.56 14.40 14.40 16.42 16.79 16.60

Uncaged Mean 91.36 77.36 72.64 68.22 65.02 63.58 62.67 62.11 61.62 60.16 59.71

S.D. 9.41 13.90 16.06 17.84 18.51 19.37 19.55 20.04 20.29 20.75 21.07


bFirst bud burst about 4 months after planting.

22

100

80

B

nN

60

20

o-n

0

0PO 2 4

caged0-o- J

f)uncaged

16 8 10

years

Figure 8.

Mean survival of Douglas-fir treeson 45 selected plots in Oregonand Washington, years 1-10 afterplanting.

growthAfter 5 years, height of cagedand uncaged trees in selectedplots averaged 60 and 35 inches(152 and 89 cm), respectively, adifference of 26 inches (66 cm).After 10 years, heights of cagedand uncaged trees (Table 10) inthese plots averaged 171 and 129inches (434 and 328 cm), respec-tively, a difference of 43 inches(109 cm). Although animal-relatedsuppression of height continuedand the mean difference in heightbetween the caged and uncagedtrees increased by about 18inches (46 cm), the growth ratesof caged and uncaged trees werenearly the same after 10 years(Fig. 9). Moreover, height differ-ences between caged and uncagedtrees appeared to stabilize atabout 42 inches (107 cm) by theeighth year.

On the '15 selected plots inWashington, mean height of cagedtrees increased from 79 inches(201 cm) at 5 years to 215inches (546 cm) at 10 years,while uncaged trees increased

Table 10.

MEAN HEIGHT OF CAGED AND UNCAGED DOUGLAS-FIR TREES ON SELECTED PLOTS,YEARS 1-10 AFTER PLANTING.(inches)

Year

Treatmenta Planting 0b 1 2 3 4 5 6 7 8 9 10

OREGON (30)Caged Mean 8.95 8.87 10.84 15.53 24.66 36.57 50.75 67.47 89.97 107.29 126.73 149.42

S.D. 2.62 2.70 2.75 3.70 6.46 10.71 16.44 21.85 27.57 33.87 39.08 46.49

Uncaged Mean 8.78 8.47 8.25 9.53 12.71 18.11 26.48 36.96 50.55 67.08 85.08 106.96S.D. 1.99 1.49 1.73 2.04 3.28 6.03 10.39 15.86 22.50 30.36 36.69 43.83

WASHINGTON (15)Caged Mean 13.40 13.35 15.91 25.31 39.40 57.42 79.25 101.36 127.36 154.39 182.71 215.28

S.D. 6.83 6.73 7.35 9.87 14.40 20.04 26.99 34.88 43.72 51.73 60.61 68.55

Uncaged Mean 13.11 12.87 12.96 16.19 23.85 35.41 51.18 67.77 89.90 114.65 142.35 172.37S.D. 6.06 5.97 5.95 6.54 7.93 11.52 18.95 27.42 37.81 47.21 55.85 66.26

BOTH STATES (45)Caged Mean 10.43 10.36 12.53 18.79 29.57 43.52 60.25 78.76 100.43 122.99 145.39 171.37

S.D. 4.88 4.87 5.29 7.86 11.95 17.38 24.38 31.03 38.47 45.95 53.74 62.49

Uncaged Mean 10.23 9.94 9.82 11.75 16.42 23.87 34.72 47.23 63.66 82.94 104.17 128.76S.D. 4.31 4.15 4.28 5.14 7.44 11.58 18.00 24.92 33.77 42.79 51.23 60.30

aNumbers in parentheses are number of plots.bFirst bud burst about 4 months after planting.

from 51 to 172 inches (130-437cm), 43 inches (109 cm) shorterthan the caged trees. I n the sameperiod, mean height of cagedtrees on the 30 selected plots inOregon increased from 51 to 149inches (130-378 cm), while un-caged trees increased from 26 to107 inches (66-272 cm), 42inches (107 cm) shorter than thecaged trees. Thus, even thoughtrees in Washington averagedabout 66 inches (168 cm) tallerthan those in Oregon at 10 years,differences between caged and un-caged trees were nearly identicalfor each state.

After 5 years, uncaged trees inWashington averaged 51 inches(130 cm) tall and were less sus-ceptible to stem damage bybrowsing, budding, or clippingthan were uncaged trees inOregon with a mean height of

0 0 I I2

only 26 inches (66 cm). After 5 Figure 9.more years' growth, however,terminal buds of shoots of most Mean height of Douglas-fir treestrees on all 45 selected plots on 45 selected plots in Oregonwere out of reach of most ani- and Washington, years 1-10 aftermals that browse, bud, and clip. planting.

200

160

caged

c 120

s0)

80

0

G)

40 0

0

e

n

0n

uncaged

0

0

07 dn

41

6 8 101

years

23

individual plot histories

succession ofdamage agentsDouglas-fir plot 314-a high-site,low-elevation plot on Weyer-haeuser Company land in south-western Washington-clearly illus-trates the pattern of animal-damage succession (Fig. 10A).Damage by grouse, deer, and hareoverlapped throughout the 10-year period. However, grouse bud-ding in the second year was theprincipal damage, peaking and de-clining to a low level after year4. Only laterals were budded af-ter the third year. Deer browsingincreased until the fifth year,then declined to a moderate levelfrom years 6 to 10 (except for asharp increase in year 8). Hareclipping, at a low level duringestablishment, increased to 25 to55 percent in years 7 to 10.

Tree survival was unaffected bythis continuous succession offeeding injuries mainly becauselaterals, not stems, were injured.After 10 years, 100 percent ofthe caged and 95 percent ofuncaged trees survived. But heightgrowth on this plantation-one ofthe fastest growing plantations inthe survey-was reduced by anamount equivalent to about a

year's growth; mean height was320 inches (813 cm) for cagedtrees and 279 inches (709 cm)for uncaged trees.

budding by grouseDouglas-fir plot 414 in the CoastRange of southwestern Washing-ton illustrates suppression prima-rily by grouse budding. However,a small amount of browsing(10%-25%), mainly by elk, oc-curred each year during years 1

to 6, and lateral clipping by hareswas moderate each year duringyears 3 to 10 (Fig. 10B).

In March 1965, 2-year-old Doug-las-fir were planted at the2,300-foot (701 m) elevation onthis high-site land managed bythe Crown Zellerbach Company.After 4 years, during which mostdamage was caused by grousebudding, height averaged 61inches (155 cm) for caged treesand 25 inches (63 cm) for un-caged trees-a difference of 26inches (66 cm). Stem damage bybudding, browsing, or clippingwas negligible after the fourthyear, although hares clipped lat-erals on about half of all uncagedtrees each year in years 5 to 10.Mean height differences increasedslightly during years 5 to 7, butprecommercial thinning in year 8removed about one-third ofuncaged trees, precluding furthercomparisons.

24

clipping by rodentsponderosa pineIn southwestern Oregon, plot 81experienced only a small amountof damage during early establish-ment (1-5 years), although pocketgophers were abundant and por-cupines were in the area. Pocketgophers caused minor damage, in-cluding damage to about half ofthe uncaged trees in the eighthyear. However, neither survivalnor height growth were muchaffected. Porcupines damagedsmall numbers of pine saplingseach year during years 6 to 10.

Three-year-old ponderosa pineswere planted on plot 83, a siteof intermediate quality at about5,000 feet (1,525 m) on theWallowa-Whitman National Forestin northeastern Oregon. The treesgrew marginally during early es-

tablishment while browsed bydeer and elk and clipped bygophers. Tree mortality, causedprincipally by gophers, reducedsurvival of uncaged trees to 43percent after 5 years; 80 percentof caged trees survived. Gopherdamage to both caged and un-caged trees increased in years 6and 7. Because of poor tree sur-vival, we discontinued observa-tions in year 8.

Figure 10.

Percent of Douglas-fir trees dam-aged by specific agents on Plot314 (A) and Plot 414 (B) in south-western Washington, years 1-10after planting.

douglas-firRodent clipping caused seedlingattrition on several Douglas-firplots such as plot 120 located onthe Siuslaw National Forest inwestern Oregon. This clearcuttinghad been broadcast burned, butshrubby vegetation rapidly re-covered to create a favorablehabitat for mountain beavers andto compound the effects of sup-pression caused by their clipping.Moderate clipping damage bymountain beavers reduced bothheight growth and survival eachyear. After 7 years, 52 percent ofuncaged trees and 80 percent ofcaged trees survived.

25

A combination of moderate dam-age by deer, hare, and mountainbeavers occurred on Douglas-firplot 20 in the Cascade Mountainsof western Oregon. During thefirst 5 years, deer browsingaveraged 20 percent per examina-tion period; clipping by mountainbeaver and hare averaged 11 per-cent. This pattern was reversed inyears 6 to 10 when the meanoccurrence of mountain beaverclipping was 27 percent and deerbrowsing was only 7 percent eachyear. Similarly, on plot 19 in thesame area, annual clipping bymountain beavers (mainly stemclipping) averaged 11 percent forthe first 5 years and 17 percentfor the second 5 years.

Browsing and clipping damagesuppressed height growth. On plot20, mean height after 10 yearswas 108 inches (274 cm) forcaged trees and 57 inches (145cm) for uncaged trees. Attritionof trees, mainly from mountainbeaver clipping, continued and re-duced survival of uncaged trees to30 percent after 10 years. Cagedtrees had a survival rate of 80percent.

browsing andtramplingby domestic stockTwo-year-old, untreated ponderosapine seedlings were planted inDecember 1963 on plot 49, a

burned clearcutting of the Bureauof Land Management in south-western Oregon. Dense herbaceouscover, chiefly perennial grassesthat developed after planting,competed with seedlings and pro-vided abundant forage for cattlegrazing there each spring andsummer throughout the study.

Initial survival was good, butnearly all uncaged seedlings werebrowsed by deer during the dor-mant season immediately afterplanting. Moderate browsing bycattle and minor trampling duringthe growing season each subse-quent year drastically reducedsurvival of unprotected trees. Af-ter 10 years, 90 percent of cagedtrees survived, but only 18 per-cent of uncaged trees. Meanheight was 84 inches (213 cm)for caged trees and 22 inches (56cm) for uncaged trees, a differ-ence of 62 inches (157 cm) (Fig.11). Furthermore, two to five ofthe caged trees had been browsedrepeatedly in years 6 to 10.

Heavy browsing damage duringinitial establishment, in combina-tion with vegetative competition,adversely affects tree survival.Furthermore, suppressed seedlingsremain vulnerable to browsing,and the cumulative effect of re-peated moderate browsing bydeer and cattle reduces bot:- treesurvival and height growth.

26

100

C

80

60

40

20

0PO(1963)

Figure 11.

Mean height of ponderosa pinetrees on plot 49 in southwesternOregon, years 1-10 after planting.

Of)

years

a

11

a

caged

A

uncaged

27

browsing by deerDouglas-fir plot 32 illustrates thatrepeated heavy browsing, chieflyby deer, decreases height growth(Figs. 12, 13). In January 1964,2-year-old Douglas-fir seedlingswere planted on a site 2, un-burned plot at low elevation inthe Oregon Coast Range. Theplantation had a high population

200

160

120

0)

C_

80

40

0

of black-tailed deer. Roosevelt elkalso occurred in the area, al-though their use of the plot wasnot noted until year 8. Seedlingsurvival on the plot was excellent(100% of caged and 96% of un-caged trees after 10 years).

From time of planting to budburst, browsing injury was negli-gible, possibly because of Thiram

caged

0

0P 0 2 4

years

a

6)

0

n

uncaged

Figure 12.

Mean height of Douglas-fir treeson plot 32 in western Oregon,years 1-10 after planting.

28

8 10

animal repellent. However, deerbrowsed new shoots of most un-caged seedlings after bud burst in1964. Browsing of new shoots onmost seedlings, with a smalleramount of stem browsing duringdormancy, was repeated throughthe 10th year. An exception wasthe dormant season of 1965when deer browsed terminalshoots of uncaged trees. Animaldamage declined from a peak of95 percent in the fifth year toabout 18 percent in the ninthyear; however, browsing of termi-nal and lateral shoots increased toabout 60 percent in the 10thyear (47% stem browsing). Stembrowsing by deer began de-creasing when mean height ofuncaged trees ranged from about13 to 19 inches (33-48 cm). Elkbrowsed (about 23% of uncagedtrees) for the first time in the10th year, which probably ac-counted for much of the in-creased damage that year Damage

of other types and by other

agents was negligible.

Repeated browsing did not affectsurvival, but it significantly sup-pressed growth (Fig 12) At theend of the fifth year, heightaveraged only 13 inches (33 cm)for uncaged trees and 69 inches(175 cm) for caged trees. After10 years, mean heights of cagedand uncaged seedlings were 168and 68 inches (427 and 173 cm),respectively-a difference of 100inches (254 cm) The uncagedtrees looked like shrubs with mul-tiple shoots because of repeatedbrowsing (Fig. 13) Growth curvesof caged and uncaged trees con-tinued to diverge for 8 years. Inyears 9 and 10, height growth ofuncaged seedlings accelerated, ap-proximating that of caged trees,however, the difference in heightbetween caged and uncaged treeswas equivalent to about 5 years'growth.

Figure 13.

Plot 32 in western Oregon, sum-mer 1974 after 10 years' growth.Hedged appearance, shrubbyform, and multiple shoots ofDouglas-fir trees illustrate the ef-fects of repeated browsing bydeer. Cages have been removedfrom the taller, protected trees.

29

discussionApart from individual plot his-tories, the findings of this 10-yearsurvey have been presented toshow the average condition, meanfrequency of damage, and meanresponse of protected and unpro-tected trees. Although valid, thesedata can be misleading becausethe amount of animal damagewas not uniform among planta-tions. For the most part, damagewas moderate in frequency, limit-ed to 1 or 2 years after planting,and confined mainly to lateralshoots with only minor effects onsurvival, growth, or both. Onsome plots, such as the 45 selec-ted plots of Douglas-fir, damagewas persistent, and repeated dam-age to stems significantly affectedgrowth. In other instances, clip-ping damage (often in combina-tion with other mortality factors)decreased stocking below ac-ceptable levels.

cagingCaged seedlings do not provide anunbiased sample of tree perform-ance. Installation of cages dis-turbed some planting spots, andcaging may have affected growth,positively or negatively. Animalsfrequently damaged seedlingswithin the cages, particularly afterterminal and lateral shoots wereexposed to browsing by deer andelk. After 5 years, the principaleffect of caging was the greatlyincreased growth of competingherbaceous and woody vegetationwhere it was protected from allfeeding by animals. In severalinstances, this dense vegetationsuppressed growth of caged seed-lings. As trees grew and becameconfined, cages were removedfrom most trees on the selectedDouglas-fir plots before comple-tion of the survey. Nonetheless,the wire netting frequently in-jured the foliage and stems ofthese caged saplings.

stand maintenanceThe plantations observed for 5years and the selected plots ob-served for 10 years received littlemaintenance except stocking sur-veys. Land managers on theseplantations did not try to bait ortrap rodent or lagomorph popula-tions, to retreat seedlings withrepellents, or to protect treeswith seedling protectors orfencing. These practices wouldhave been incompatible with sur-vey objectives, and none wereproposed. A few plantations wereinterplanted, treated with phe-noxy herbicides or hand-grubbedto "release" conifers, or precom-mercially thinned.

More intensive management dur-ing stand establishment mighthave reduced the impact of ani-mal damage. Stand maintenancecan reduce carrying capacity ofhabitats for small or large mam-mals. By promoting conifergrowth, maintenance can reducethe period of exposure to signifi-cant animal damage and increasethe capacity of conifers to sustaindamage. I n well-stocked stands,precommercial and commercialthinning can remove trees sup-pressed by animals (and otheragents) and thus minimize ap-parent adverse effects.

damagedistributionNeither the distribution nor theincidence of deer use of Douglas-fir is random (Crouch 1968,Hines 1973). Deer confined in afenced enclosure in westernOregon in winter heavily browsedDouglas-fir trees on most sites,but browsed little at other siteswithin the enclosure. Deer dam-age to Douglas-fir plantations onVancouver Island concentrated inareas seldom exceeding 2 acres or0.8 ha (Smith and Walters 1965).Of Douglas-fir stem browsed byelk, 95 percent were in areasadjacent to standing timber; only3 percent of the high-use areaswere more than 300 yards (274

30

A

m) from timber (Harper 1969).Thus, even on plantations thatreceive only light overall use,damage may be concentrated suf-ficiently to cause serious loss.

Crouch (1968) and Hines (1973)concluded that the primary factorregulating deer use of Douglas-firis the relation of deer density tothe available quantity of morepalatable forage. In areas of com-parable deer density, coniferbrowsing was affected by winterweather and availability of forage.Browsing of Douglas-fir trees inwinter was also related to seed-ling size, elevation, aspect, slope,and amount of soil disturbance.In the Tillamook Burn of westernOregon, both investigators foundthat deer use was greatest belowelevations of 2,000 feet (610 m),on south-facing slopes with gradesof less than 60 percent, and onsoils disturbed by logging.

Elk transplanted by state agenciesmay have contributed to changesin damage patterns on some plan-tations. One pattern showed in-creased elk damage as standsdeveloped. For example, fiveDouglas-fir plots in northwesternOregon, inhabited by both deerand elk, were browsed mainly bydeer during the first 5 years; elkbrowsing became common only asstands grew older. Harper (1969)showed that elk use was higheston clearcuttings that were 6 to 8years old.

Browsing followed a similar pat-tern on a Douglas-fir plot inwestern Washington. Moderate toheavy deer browsing, but no elkbrowsing, occurred from years 1

to 5; however, from years 6 to10, browsing was principally byelk. Although browsing decreasedeach year (from 54% to 4%),most was stem browsing.

On five plots in western Oregonand Washington, elk browsing wasnot observed during years 1 to 5,then only infrequently as planta-tions developed. On one plot inwestern Oregon, deer browsed

exclusively from years 1 to 9,but in the 10th year, elk browsedstems of 23 percent of uncagedseedlings averaging 67 inches (170cm) in height. In these instances,elk probably had extended theirrange to include the clearcuttings.

damage tosaplings and treesIn several instances, animals dam-aged saplings and pole-size trees.Douglas squirrels clipped terminalleaders and upper lateral shootsof trees on seven Douglas-fir plotsin Washington and six in Oregon.This type of damage, reported byFisch and Dimock (1978), oc-curred mainly during years 6 to10. Woodrats damaged 10-year-oldDouglas-fir trees in a south-western Oregon plot where a

dense young stand provided a

favorable habitat (Hooven 1959),although the woodrats had beenabsent during plantation establish-ment. Bear damage, which occursmost frequently on pole-size trees10 to 30 years old (Poelker andHartwell 1973), occurred in the10th year on one Douglas-fir plotin western Washington. In oneinstance, damage to Douglas-firsaplings was attributed to band-tailed pigeons landing on andbreaking the succulent leader.

damage agentsTo rank damage types and animalagents in order of destructivenessto tree regeneration, both severityand amount of damage must beevaluated. Types of damage over-lapped in nearly all plantations,and apportioning precise losses toeach type or agent is impossible.However, we can reasonably inferthat stem clipping by hares, rab-bits, and mountain beavers causedmost animal-related mortality inDouglas-fir. Likewise, clipping androot cutting by pocket gophersprobably caused most animal-related mortality in ponderosapine. Height losses in both Doug-las-fir and ponderosa pine resultedchiefly from combinations ofbrowsing and clipping. Because

deer browsed both species almosteverywhere, exceeding damage byall other agents combined, we canreasonably infer that deer brows-ing reduced tree height more thanany other damage.

impact of damageAfter 5 years, differences betweenprotected and unprotected treesin average plantations show thatanimals substantially reducedheight and survival of Douglas-fir(24% and 20%, respectively) andponderosa pine (22% and 31%,respectively). Tree mortality,usually from clipped stems orroots, becomes significant whenstocking is reduced below an ac-ceptable production level and re-planting is required.

Most plantations can sustainminor damage without significantimpact on stocking or growth.For example, Campbell and Evans(1975a) estimated that stems of35 percent of the trees in a

plantation can be deer browsedbefore stands lose significantheight. On many sites, regenera-tion from natural seedfall con-tributes to stocking. Althoughyield may be reduced when opti-mum stocking is not achievedpromptly, natural regenerationoften offsets the effects of animaldamage on tree survival.

Suppressed height growth, themost common and widespread ef-fect of animal damage, suggestsextension of rotation, althoughthinning when stocking exceedsoptimum for the site could mini-mize the difference between dam-aged and undamaged trees. Smithand Walters (1965) calculatedthat a height advantage of 10inches (25 cm) for Douglas-fir atplanting may, if the advantagepersists, mean a difference of 2.6years in length of the rotation.Mitchell (1964) concluded thatproductivity of Douglas-fir planta-tions on Vancouver Island wouldnot be seriously reduced at rota-tion age, despite an average re-duction in tree height of 6 to 24

31

conclusionsinches (15-61 cm) from deerbrowsing over 8 to 10 years.

In this survey, height of protec-ted and unprotected trees differedby an average of 43 inches (109cm) after 10 years on plantationsheavily damaged by deer andother animals. This suggests thatthe growth differential willpersist, measurably reducing ordelaying yield. However, asCrouch (1969) noted, the relationbetween browsing of trees asseedlings or saplings and theircondition at rotation age has notbeen described.

32

The survey of forest plantationsin Oregon and Washington wasdesigned to comprehensivelyevaluate the impact of animaldamage. We believe that the find-ings represent a reasonably ac-curate appraisal. Moderate toheavy browsing, budding, andclipping damage-principally bydeer, grouse, and hares-damagedplantations throughout both statesduring stand establishment. Onthe average, animal damage ad-versely affected tree survival,causing 33 percent of the mor-tality on Douglas-fir plots and 43percent of the mortality on pon-derosa pine plots. Animal damagesuppressed tree height the equiva-lent of about 1.5 years' growthafter 5 years. On Douglas-fir plan-tations experiencing heavy dam-age, height suppression was equiv-alent to about 2.5 years' growthat both 5 and 10 years afterplanting.

We believe that mortality factorsmust be evaluated carefully anddamage must be identified accu-rately before control measures areundertaken. Minor browsing, bud-ding, or clipping injuries-especially to established trees-canbe disregarded, and control meas-ures are not indicated. Becausedeer browsing is so widespreadand pocket gopher and mountainbeaver damage so serious, moreresearch is justified to developeffective control measures and re-forestation practices designed toalleviate damage by these animals.

Stand damage in plantations ex-posed to heavy animal use, espe-cially during seedling establish-ment, warrants expenditure forprotective measures. Areas ofpotentially heavy damage shouldbe identified early (before refor-estation, if possible), and the bestavailable combination of controlmeasures should be applied.Recognition of the distribution ofdamage in relation to manage-ment practices and site featureswill help identify high-risk areas.The findings of this survey offerthe basis for developing predic-tion models to identify areas thatwill be exposed to significant ani-mal damage. Such predictors areurgently needed.

references citedANONYMOUS. 1975-76. Thiramuse in reforestation of Douglas-fir: effects of animal browsingand tree planter health. A stu-dent-originated studies projectfunded by Nat. Sci. Found. Univ.Oreg., Eugene. 92 p.

BLACK, H. C., E. J. DIMOCK II,W. E. DODGE, and W. H.LAWRENCE. 1969. Survey ofanimal damage on forest planta-tions in Oregon and Washington,p. 388-408 I N Trans. 34th NorthAm. Wildl. Nat. Resour. Conf.

CAMPBELL, D. L., and J.EVANS. 1975a. Improving wild-life habitat in young Douglas-firplantations, p. 202-208 I N Trans.40th North Am. Wildl. Nat. Re-sour. Conf.

CAMPBELL, D. L., and J.EVANS. 1975b. "Vexar" seedlingprotectors to reduce wildlife dam-age to Douglas-fir. U.S. FishWildl. Serv., Wildl. Res. Center,Denver, Colo. Wildl. Leafl. 508.11 p.

CROUCH, G. L. 1968. Forageavailability in relation to deerbrowsing of Douglas-fir seedlingsby black-tailed deer. J. Wildl.Manage. 32(3):542-553.

CROUCH, G. L. 1969. Deer andreforestation in the Pacific North-west, p. 63-66 I N Proc., Symp.Wildl. and Reforestation in thePac. Northwest. Oreg. State Univ.,Sch. For., Corvallis.

DIMOCK, E. J., II, and H. C.BLACK. "1969. Scope and eco-nomic aspects of animal damagein California, Oregon and Wash-ington, p. 10-14 IN Proc., Symp.Wildl. and Reforestation in thePac. Northwest. Oreg. State Univ.,Sch. For., Corvallis.

FISCH, G. G., and E. J.DIMOCK, II. 1978. Terminal andlateral shoot clipping by Douglassquirrels in young Douglas-fir. J.Wildl. Manage. 42(2):415-418.

HARPER, J. A. 1969. Relationof elk reforestation in the PacificNorthwest, p. 67-71 I N Proc.,Symp. Wildl. and Reforestation inthe Pac. Northwest. Oreg. StateUniv., Sch. For., Corvallis.

HINES, W. W. 1973. Black-taileddeer populations and Douglas-firreforestation in the TillamookBurn, Oregon. Oreg. State GameComm., Res. Div., Salem. GameRes. Bull. 3. 59 p.

HOOVEN, E. F. 1959. Dusky-footed woodrat in young Doug-las-fir. Oreg. For. Res. Center,Corvallis. Res. Note 41. 24 p.

LAWRENCE, W. H. 1958. Wild-life-damage control problems onPacific Northwest tree farms, p.146-151 I N Trans. 23rd NorthAm Wildl. Conf.

LAWRENCE, W. H., N. B.KVERNO, and H. D. HART-WELL. 1961. Guide to wildlifefeeding injuries on conifers in thePacific Northwest. West. For.Conserv. Assn. 44 p.

MITCHELL, K. J. 1964. Heightgrowth losses due to animal feed-ing in Douglas-fir plantations,Vancouver Island, British Colum-bia. For. Chron. 40:298-307.

MOORE, A. W. 1940. Wildlifeanimal damage to seed and seed-lings on cut-over Douglas-fir landsof Oregon and Washington. U.S.Dep. Agric., Tech. Bull. 706. 28p.

POELKER, R. J., and H. D.HARTWELL. 1973. Black bear ofWashington. Wash. State GameDep., Olympia. Biol. Bull. 14.180 p.

SMITH, J. H. G., and J. WALT-ERS. 1965. Influence of seedlingssize on growth, survival and costof growing Douglas-fir. Univ. B.C., Fac. For., Vancouver. Res.Note 50. 7 p.

33

appendix tablesTable 1 A. Table 2A.

ANIMAL-DAMAGED DOUGLAS-FIR TREES IN ANIMAL-DAMAGED DOUGLAS-FIR TREESOREGON AND WASHINGTON BY OWNERSHIP, IN OREGON BY OWNERSHIP, YEARS 1-5YEARS 1-5 AFTER PLANTING. AFTER PLANTING.(mean annual percent) (mean annual percent)

Ownershipa Ownershipa

USFS BLM WDNR OSDF Private USFS BLM OSDF PrivateDamage (57)b X411(10) (25) (32) Damage (33) b (41) (25) (17)

TYPEBarking 0.29 0.13 0.18 0.01 0.19

TYPEBarking 0.23 0.13 0.01 0.07

BrowsingOverall 12.12 25.20 25.10 27.54 29.71

BrowsingOverall 15.06 25.20 27.54 32.27

Stem 10.21 22.64 18.01 22.42 22.36 Stem 13.20 22.64 22.42 26.43Budding c

Overall 2.18 1.80 3.90 0.12 6.72Budding

Overallc 3.02 1.80 0.12 1.26Stem 0.53 0.06 2.54 0.02 2.38 Stem 0.57 0.06 0.02 0.08

ClippingOverall 4.57 2.47 9.84 4.66 11.38

ClippingOverall 5.09 2.47 4.66 9.48

Stem 2.49 1.43 4.82 2.46 5.19 Stem 2.40 1.43 2.46 6.67Root cutting 0.00 0.08 0.00 0.02 0.02 Root cutting 0.00 0.08 0.02 0.03Pulling 0.01 0.03 0.06 0.38 0.05 Pulling 0.01 0.03 0.38 0.08Trampling 0.26 0.08 0.29 0.44 0.22 Trampling 0.37 0.08 0.44 0.04Other 0.08 0.02 0.08 0.03 0.11 Other 0.04 0.02 0.03 0.02

All Damage 18.85 29.10 36.80 32.52 44.36 All Damage 22.93 29.10 32.52 42.52Stem Damage 13.59 24.24 25.20 25.42 30.08 Stem Damage 16.49 24.24 25.42 33.20

AGENTDeer 11.43 24.52 21.51 19.64 24.35

AGENTDeer 14.65 24.52 19.64 32.44

Domestic stock 0.01 0.02 0.06 0.01 0.01 Domestic stock 0.01 0.02 0.01 0.02Elk 0.95 0.80 5.24 8.35 6.44 Elk 0.71 0.80 8.35 0.11Gopher 0.01 0.14 0.02 0.00 0.01 Gopher 0.01 0.14 0.00 0.03Grousec 2.26 1.80 3.91 0.12 6.73 Grousec 3.09 1.80 0.12 1.26Hare 3.11 1.97 7.86 3.98 8.72 Hare 4.24 1.97 3.98 7.07Mountain beaver 0.61 0.45 1.91 0.73 2.66 Mountain beaver 0.48 0.45 0.73 2.33Microtine 0.05 0.02 0.09 0.00 0.01 Microtine 0.04 0.02 0.00 0.00Porcupine 0.00 0.00 0.00 0.00 0.00 Porcupine 0.00 0.00 0.00 0.00Other 0.88 0.00 0.06 0.02 0.04 Other 0.44 0.00 0.02 0.00

aUSFS-U.S. Forest Service; BLM-Bureau of LandManagement; WDNR-Washington Department of NaturalResources; OSDF-Oregon State Department of Forestry.

aUSFS-U.S. Forest Service; BLM-Bureau of LandManagement; WDNR-Washington Department of NaturalResources; OSDF-Oregon State Department ofForestry.

bNumbers in parentheses are number of plots.

cFrequency of overall budding and of grouse damageshould be identical because grouse are the only agents.Small differences are errors.


cFrequency of overall budding and of grousedamage should be identical because grouse are the

only agents. Small differences are errors.

34

ez

Table 3A.

ANIMAL-DAMAGED DOUGLAS-FIRTREES IN WASHINGTON BY OWN-ERSHIP, YEARS 1-5 AFTERPLANTING.(mean annual percent)

Ownershipa

DamageUSFS WDNR Private(24)b (10) (15)

TYPEBarkingBrowsing

OverallStem

BuddingOverallsStem

ClippingOverallStem

Root cuttingPullingTramplingOther

All DamageStem Damage

0.38 0.18 0.33

8.06 25.10 26.816.09 18.01 17.74

1.02 3.90 12.900.49 2.54 4.98

3.85 9.84 13.542.61 4.82 3.500.00 0.00 0.020.01 0.06 0.010.12 0.29 0.430.12 0.08 0.21

13.26 36.80 46.459.60 25.20 26.55

AGENTDeer 6.99 21.51 15.18Domestic stock 0.00 0.06 0.00Elk 1.28 5.24 13.62Gopher 0.00 0.02 0.00Grouses 1.12 3.91 12.93Hare 1.55 7.86 10.59Mountain beaver 0.80 1.91 3.034icrotine 0.07 0.09 0.02Porcupine 0.00 0.00 0.00Other 1.48 0.06 0.09

aUSFS-U.S. Forest Service; BLM-Bureau ofLand Management; WDNR-Washington Departmentof Natural Resources; OSDF-Oregon StateDepartment of Forestry.

bNumbers in parentheses are number ofplots.

cFrequency of overall budding and grousedamage should be identical because grouseare the only agents. Small differencesare errors.

Table 4A.

ANIMAL-DAMAGED DOUGLAS-FIR TREES ON SLASHTREATED PLOTS IN OREGON AND WASHINGTON,YEARS 1-5 AFTER PLANTING.(mean annual percent)

OREGON WASHINGTON BOTH STATESBurned Unburned Burned Unburned Burned Unburned

Damage (79)a (37) (36) (13) (115) (50)

TYPEBarkingBrowsing

OverallStem

Budding b

OverallStem

Clipping

0.10 0.17 0.35 0.24 0.18 0.19

23.86 23.85 14.83 24.05 21.03 23.9020.94 19.43 10.67 16.03 17.73 18.55

2.20 0.64 2.54 12.72 2.31 3.780.28 0.02 1.32 4.94 0.61 1.30

Overall 3.94 6.35Stem 2.09 3.99

Root cutting 0.01 0.08Pulling 0.10 0.13Trampling 0.21 0.28Other 0.02 0.05

All Damage 29.70 30.79Stem Damage 23.50 23.82

6.19 13.14 4.65 8.123.11 3.96 2.41 3.980.00 0.02 0.01 0.070.03 0.00 0.08 0.100.17 0.45 0.20 0.320.14 0.15 0.05 0.08

22.75 43.39 27.52 34.0715.43 25.01 20.98 24.13

AGENTDeer 22.12 21.18 12.26 13.03 19.03 19.06Domestic stock 0.01 0.02 0.02 0.00 0.01 0.01Elk 1.99 2.97 3.21 13.22 2.37 5.64Gopherb 0.02 0.13 0.00 0.02 0.01 0.10Grouse 2.23 0.65 2.62 12.73 2.35 3.79Hare 3.25 4.97 3.84 10.48 3.43 6.40Mountain beaver 0.53 1.36 1.37 2.66 0.80 1.69Microtine 0.02 0.02 0.07 0.02 0.03 0.02Porcupine 0.00 0.00 0.00 0.00 0.00 0.00Other 0.18 0.01 1.00 0.10 0.44 0.03


bFrequency of overall budding and of grouse damage should be identicalbecause grouse are the only agents. Small differences are errors.

35

Table 5A. Table 6A.

ANIMAL-DAMAGED DOUGLAS-FIR TREES ANIMAL-DAMAGED DOUGLAS-FIR TREESON DIFFERENT ASPECTS IN OREGON AND ON DIFFERENT ASPECTS IN OREGON,WASHINGTON, YEARSING.

1-5 AFTER PLANT- YEARS 1-5 AFTER PLANTING.(mean annual percent)

(mean annual percent) Aspect

Nort East South West Level

Aspect Damageh

29) (8) (53) (18) (8)

North East South West Level

Damage (37)a (12) (75) (28) (13) TYPEBarking 0.05 0.08 0.16 0.10 0.21

TYPEBarking 0.10 0.09 0.25 0.13 0.23

BrowsingOverall 20.36 12.11 27.93 24.44 20.00

Browsing Stem 17.59 9.16 24.11 21.37 15.93

Overall 18.13 13.92 26.27 21.03 16.66 Budding b

Stem 15.31 10.50 21.61 17.60 12.29 Overall 0.88 1.57 2.48 1.25 0.70

Budding b Stem 0.14 0.19 0.28 0.14 0.00

Overall 1.14 1.71 4.20 2.18 1.22 ClippingStem 0.28 0.48 1.18 1.06 0.05 Overall 4.89 7.78 3.13 6.50 7.45

Clipping Stem 3.32 4.57 1.78 3.46 2.87

Overall 4.95 7.57 5.12 5.17 10.57 Root cutting 0.08 0.06 0.00 0.05 0.05

Stem 3.34 4.15 2.42 2.49 3.96 Pulling 0.03 0.00 0.15 0.06 0.31

Root cutting 0.06 0.04 0.00 0.03 0.05 Trampling 0.16 0.05 0.33 0.08 0.42

Pulling 0.02 0.00 0.11 0.04 0.23 Other 0.07 0.00 0.01 0.02 0.03

Trampling 0.20 0.04 0.33 0.10 0.29 All Damage 26.09 20.99 33.32 31.80 27.81Other 080 0.10 0.07 0.03 0.02.

Stem Damage 21.18 14.03 26.49 25.09 19.49

All D a e 24 18 7022 34 20 8027 27 56am g

Stem Damage.

19.11

.

15.24.

25.56.

21.17.

16.86 AGENTDeer 19 24 12 17 25 29 23 87 13.23

AGENT Domestic stock.

0.00.

0.05

.

0.01

.

0.00 0.05

Deer 16.63 13.98 22.36 18.77 11.99 Elk 1.22 0.03 2.99 0.81 7.29

Domestic stock 0.00 0.03 0.02 0.00 0.03 Gopherb 0.15 0.00 0.01 0.05 0.05

Elk 1.70 0.02 4.41 3.23 5.38 Grouse 0.90 1.57 2.51 1.25 0.74

Gopherb 0.13 0.00 0.01 0.03 0.03 Hare 3.70 3.71 2.58 6.00 7.38

Grouse 1.16 1.73 4.25 2.18 1.24 Mountain beaver 0.97 4.10 0.44 0.40 0.09

Hare 3.30 4.63 3.75 4.78 9.42 Microtine 0.00 0.00 0.03 0.00 0.09

Mountain beaver 1.43 2.78 0.88 0.31 1.13 Porcupine 0.00 0.00 0.00 0.00 0.00

Microtine 0.01 0.00 0.03 0.01 0.14 Other 0.27 0.00 0.11 0.06 0.02

Porcupine 0.00 0.00 0.00 0.00 0.00

Other 0 27 210 0.51 0.05 0.02a

. .

Numbers in parentheses are number of plots.


bFrequency of overall budding and of grouse damageshould be identical because grouse are the only agents.Small differences are errors.

bFrequency of overall budding and of grouse damageshould be identical because grouse are the only agents.Small differences are errors.

36

Table 7A.

ANIMAL-DAMAGED DOUGLAS-FIR TREESON DIFFERENT ASPECTS IN WASHINGTON,YEARS 1-5 AFTER PLANTING.(mean annual percent)

Aspect

DamageNorth

(8)East(4)

South(22)

West(10)

Level(5

TYPEBarking 0.26 0.12 0.45 0.19 0.27Browsing

Overall 10.08 17.54 22.28 14.91 11.31Stem 7.05 13.18 15.59 10.81 6.45

Budding b

Overall 2.12 2.00 8.34 3.84 2.05Stem 0.78 1.05 3.34 2.72 0.12

ClippingOverall 5.18 7.15 9.92 2.76 15.56Stem 3.40 3.31 3.96 0.74 5.70

Root cutting 0.00 0.00 0.00 0.00 0.05Pulling 0.00 0.00 0.02 0.00 0.11Trampling 0.35 0.00 0.34 0.13 0.09Other 0.10 0.29 0.20 0.04 0.00All Damage 17.28 26.10 36.30 20.59 27.17Stem Damage 11.59 17.65 23.31 14.11 12.65

AGENTDeer 7.15 17.60 15.32 9.58 10.01Domestic stock 0.00 0.00 0.03 0.00 0.00Elk 3.47 0.00 7.84 7.58 2.33Gopherb 0.03 0.00 0.00 0.00 0.00Grouse 2.09 2.06 8.46 3.84 2.05Hare 1.85 6.49 6.58 2.58 12.69Mountain beaver 3.11 0.14 1.95 0.16 2.80Microtine 0.03 0.00 0.05 0.02 0.22Porcupine 0.00 0.00 0.00 0.00 0.00Other 0.23 0.62 1.46 0.04 0.00

aNumbers in parentheses are number of plots.bFrequency of overall budding and of grouse damageshould be identical because grouse are the only agents.Small differences are errors.

Table 8A.

ANIMAL-DAMAGED DOUGLAS-FIRTREES ON DIFFERENT SLOPES INOREGON AND WASHINGTON, YEARS 1-5AFTER PLANTING.(mean annual percent)

Slope0-5, 6-25% 26-50% 51+%

Damage (23)a (70) (43) (29)

TYPEBarking 0.27 0.15 0.18 0.18Browsing

Overall 18.37 25.55 18.08 21.56Stem 14.55 20.88 15.39 17.52

Budding b

Overall 0.76 4.30 2.55 0.93Stem 0.07 1.38 0.76 0.15

ClippingOverall 7.84 6.37 4.66 3.93Stem 3.56 2.72 2.78 2.89

Root cutting 0.05 0.05 0.00 0.00Pulling 0.16 0.04 0.03 0.20Trampling 0.22 0.17 0.17 0.51Other 0.01 0.06 0.09 0.06

All Damage 26.54 34.40 24.98 26.76Stem Damage 18.71 25.10 19.04 21.12

AGENTDeer 14.05 22.67 17.23 16.94Domestic stock 0.03 0.01 0.01 0.01Elk 4.94 3.53 1.02 5.16Gopherb 0.02 0.09 0.00 0.00Grouse 0.77 4.33 2.60 0.93Hare 5.66 5.53 3.53 1.58Mountain beaver 2.16 0.64 0.37 2.26Microtine 0.08 0.02 0.04 0.00Porcupine 0.00 0.00 0.00 0.00Other 0.01 0.22 0.74 0.16

Numbers in parentheses are number of plots.bFrequency of overall budding and of grouse damageshould be identical because grouse are the onlyagents. Small differences are errors.

37

Table 9A. Table 10A.

ANIMAL-DAMAGED DOUGLAS-FIR TREES ANIMAL-DAMAGED DOUGLAS-FIR TREESON DIFFERENT SLOPES IN OREGON, ON DIFFERENT SLOPES IN WASHINGTON,YEARS 1-5 AFTER PLANTING. YEARS 1-5 AFTER PLANTING.(mean annual percent) (mean annual percent)

Slope Slope

0-5% 6-25% 26-50% 51+% 0-5% 6-25% 26-50% 51+%

Damage (14)a (46) (31) (25) Damage (9)a (24) (12) (4)

TYPEBarking 0.14 0.11 0.07 0.20

TYPEBarking 0.48 0.23 0.48 0.06



Stem 18.37 23.48 18.06 19.07 Stem 8.60 15.91 8.48 7.84Budding b

Overall 0.42 2.31 2.27 0.61Budding b

Overall 1.28 8.10 3.27 2.92Stem 0.00 0.41 0.12 0.02 Stem 0.17 3.24 2.40 0.93



Stem 2.40 2.71 2.51 3.06 Stem 5.37 2.75 3.49 1.82Root cutting 0.07 0.07 0.00 0.00 Root cutting 0.03 0.00 0.00 0.00Pulling 0.21 0.06 0.04 0.24 Pulling 0.09 0.00 0.02 0.00Trampling 0.27 0.12 0.18 0.49 Trampling 0.15 0.27 0.14 0.63Other 0.02 0.03 0.02 0.04 Other 0.00 0.12 0.27 0.19

All Damage 27.42 33.85 27.07 28.22 All Damage 25.16 35.46 19.56 17.65Stem Damage 21.25 26.74 20.75 22.69 Stem Damage 14.75 21.96 14.61 11.36

AGENTDeer 17.95 26.05 19.80 18.70

AGENTDeer 7.97 16.18 10.57 5.94

Domestic stock 0.05 0.01 0.01 0.01 Domestic stock 0.00 0.02 0.00 0.00Elk 4.17 1.19 1.00 4.92 Elk 6.15 8.03 1.08 6.65Gopher 0.03 0.13 0.00 0.00 Gopher

b

0.00 0.01 0.00 0.00Grouseb 0.44 2.35 2.27 0.61 Grouse 1.28 8.13 3.47 2.92Hare 4.60 4.44 4.07 1.83 Hare 7.30 7.63 2.16 0.00Mountain beaver 0.77 0.14 0.51 2.37 Mountain beaver 4.31 1.61 0.02 1.53Microtine 0.05 0.02 0.02 0.00 Microtine 0.12 0.03 0.08 0.00Porcupine 0.00 0.00 0.00 0.00 Porcupine 0.00 0.00 0.00 0.00Other 0.01 0.30 0.01 0.03 Other 0.00 0.09 2.61 1.00


bFrequency of overall budding and of grouse damageshould be identical because grouse are the onlyagents. Small differences are errors.

aNumbers in parentheses are number of plots.

bFrequency of overall budding and of grouse damageshould be identical because grouse are the only

agent. Small differences are errors.

38


ANIMAL-DAMAGED DOUGLAS-FIR ANIMAL-DAMAGED DOUGLAS-FIRTREES BY SITE CLASS IN OREGON AND TREES BY SITE CLASS IN OREGON,WASHINGTON, YEARS 1-5 AFTER YEARS 1-5 AFTER PLANTING.

(mean annual percent)mean annual percent)

Site classSite class

1&2 3 4&51&2

a

3 4&5Damage 33

a(65) (18)

Damage (46) (88) (31)

TYPETYPEBarking 0 07 0.10 0.29

BarkingBrowsing

0.16 0.14 0.33 Browsing.

Overall 22.32 27.15 14.77Overall 24.12 24.04 12.55

Stem 19.32 23.06 13.19Stem 19.14 20.03 10.42

BuddingBudding b

b

Overall 1.06 2.01 1.81Overall 4.23 2.41 1.56

Stem 0.00 0.32 0.14Stem

Clipping1.37 0.72 0.29

ClippingOverall 6.89 3.93 3.56

Overall 9.68 4.38 563

Stem 4.33 2 50.

1 83Stem 4.10 2.26 1.70

. .

Root cutting 0.03 0.05 0.00Root cutting 0.03 0 04 0 00. .

Pulling 0.28 0.03 0.07Pulling 0.22 0.02 0.04

Trampling 230 0.18 0.43Trampling 0.25 0.21 0.30

Other.

0.02 0.03 0.04Other 0.05 0.05 0.10

All Damage 30 17 32.83 19.77All Damage 35.96 30.34 17.56Stem Damage

.

23.61 25.85 15.47Stem Damage

AGENT

25.02 23.46 13.01

AGENTDeer 19.08 25.51 13.51Deer 18.36 22.12 11.32 Domestic stock 0.00 0.01 0.03

Domestic stock 0.00 0.02 0.02Elk 583 1.84 1.62

Elk b 6.68 2.28 1.50Gopher

.

0.02 0.09 0.00Grouse 4 24 2 42 1 67

b. . .

Grouse 1.06 2.02 1.87Hare 8.07 2.84 3.03

Hare 5 99 2.78 3.43Mountain beaver 1.65 1 06 0 22.

. .Mountain beaver 0.94 0.90 0.14

Microtine 0.02 0.02 0.05Microtine 0 00 0.03 0.03

Porcupine 0.00 0.00 0.00 Porcupine.

0.00 0.00 0.00Other 0.05 0.45 0.33

Other 0.03 0.22 0.00


bFrequency of overall budding and of grousedamage should be identical because grouse arethe only agents. Small differences are errors.



39

PLANTING.

Table 13A.

ANIMAL-DAMAGED DOUGLAS-FIR

Table 14A.

ANIMAL-DAMAGED DOUGLAS-FIR TREES AT DIFFERENTTREES BY SITE CLASS IN WASHING-TON, YEARS 1-5 AFTER PLANTING.(mean annual percent)

ELEVATIONS IN OREGON AND WASHINGTON, YEARS 1-5AFTER PLANTING.(mean annual percent)

Site class Elevation, feet

1&2 3 4&5 0- 600- 1100- 1600- 2100- 2600- 3100-

Damage (13)a (23) (13) 500

a

1000 1500 2000 2500 3000 3500 3600+

Damage (15) (32) (35) (25) (23) (10) (13) (12)

TYPEBarking 0.38 0.26 0.38 TYPE

Browsing Barking 0.23 0.20 0.09 0.12 0.10 0.07 0.35 0.52

Overall 28.68 15.24 9.47 Browsing

Stem 18.68 11.48 6.59 Overall 19.79 21.43 36.20 20.44 22.19 14.71 7.24 8.46

Budding b Stem 14.32 16.69 31.09 15.75 18.64 13.07 6.48 7.64

Overall 12.28 3.55 1.22 Budding b

Stem 4.84 1.84 0.50 Overall 3.92 1.27 2.26 2.05 6.38 1.70 2.50 2.41

Clipping Stem 1.41 0.48 0.39 1.02 1.73 0.15 1.38 0.00

Overall 16.75 5.65 3.55 Clipping

Stem 4.93 3.18 2.01 Overall 12.18 7.03 3.57 4.47 6.74 2.10 6.53 2.93

Root cutting 0.02 0.00 0.00 Stem 5.82 3.87 1.59 3.08 2.47 0.84 3.63 1.64

Pulling 0.06 0.01 0.00 Root cutting 0.02 0.00 0.12 0.00 0.00 0.00 0.00 0.00

Trampling 0.30 0.28 0.13 Pulling 0.04 0.01 0.23 0.11 0.06 0.00 0.00 0.02

Other 0.13 0.12 0.18 Trampling 0.15 0.21 0.33 0.21 0.22 0.02 0.14 0.51

Other 0.10 0.08 0.03 0.03 0.05 0.00 0.17 0.07All Damage 50.67 23.30 14.49Stem Damage 28.61 16.69 9.60 All Damage 33.66 29.12 41.08 26.79 33.16 18.23 16.40 13.84

Stem Damage 21.53 21.18 33.48 20.10 22.99 14.04 11.94 9.94

AGENTDeer 16.51 12.53 8.30 AGENT

Domestic stock 0.00 0.02 0.00 Deer 15.84 17.59 30.04 18.81 20.84 14.61 7.33 8.24

Elk 14.57 3.52 1.33 Domestic stock 0.00 0.02 0.02 0.00 0.01 0.04 0.00 0.00

Gopher 0.00 0.01 0.00 Elk 5.80 4.14 6.51 1.99 2.09 0.16 0.00 0.64

Grouseb 12.31 3.55 1.40 Gopherb 0.02 0.00 0.17 0.00 0.00 0.00 0.00 0.03

Hare 13.34 3.00 2.47 Grouse 3.92 1.28 2.26 2.07 6.38 1.70 2.71 2.54

Mountain beaver 3.44 1.50 0.35 Hare 10.10 5.34 2.28 2.64 6.22 2.01 3.69 3.00

Microtine 0.09 0.02 0.09 Mountain beaver 2.05 1.78 1.22 1.40 0.45 0.03 0.02 0.00

Porcupine 0.00 0.00 0.00 Microtine 0.07 0.02 0.00 0.02 0.02 0.03 0.02 0.00

Other 0.10 1.13 0.78 Porcupine 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Other 0 05 060 020 0.45 0.04 0.00 2.82 0.00. . .




bFrequency of overall budding and of grouse damage should be identical

because grouse are the only agents. Small differences are errors.

40

Table 15A.

ANIMAL-DAMAGED DOUGLAS-FIR TREES AT DIFFERENTELEVATIONS IN OREGON, YEARS 1-5 AFTER PLANTING.(mean annual percent)

Elevation, feet0- 600- 1100- 1600- 2100- 2600- 3100-500 1000 1500 2000 2500 3000 3500 3600+

Damage (5)a (24) (30) (16) (15) (8) (6) (12)

TYPEBarking 0.05 0.14 0.08 0.04 0.07 0.05 0.00 0.52Browsing

Overall 16.58 20.38 37.48 23.35 25.68 17.59 11.63 8.46Stem 13.67 16.78 33.06 18.23 22.48 15.72 10.72 7.64

Budding b

Overall 2.24 0.24 1.13 1.16 3.90 2.12 3.98 2.41Stem 0.07 0.00 0.07 0.13 0.28 0.19 1.97 0.00

ClippingOverall 11.19 6.98 2.40 5.91 4.04 2.52 6.75 2.93Stem 7.56 3.83 1.40 4.05 2.37 0.95 2.21 1.64

Root cutting 0.00 0.00 0.14 0.00 0.00 0.00 0.00 0.00Pulling 0.00 0.01 0.27 0.16 0.10 0.00 0.00 0.02Trampling 0.16 0.17 0.29 0.25 0.13 0.03 0.20 0.51Other 0.00 0.05 0.00 0.02 0.05 0.00 0.03 0.07All Damage 29.40 27.28 40.86 30.33 33.33 21.89 21.93 13.84Stem Damage 21.07 20.62 34.91 22.87 25.35 16.83 15.11 9.94

AGENTDeer 14.80 18.19 32.82 21.08 25.98 17.47 11.73 8.24Domestic stock 0.00 0.00 0.03 0.00 0.02 0.05 0.00 0.00Elk 1.92 2.35 4.93 2.68 0.05 0.20 0.00 0.64Gopherb 0.00 0.00 0.20 0.00 0.00 0.00 0.00 0.03Grouse 2.24 0.24 1.13 1.16 3.90 2.12 4.09 2.54Hare 10.89 5.88 1.57 3.62 3.24 2.48 5.89 3.00Mountain beaver 0.28 1.16 0.75 1.89 0.70 0.00 0.00 0.00Microtine 0.00 0.03 0.00 0.00 0.01 0.00 0.00 0.00Porcupine 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00Other 0.00 0.04 0.01 0.45 0.07 0.00 0.90 0.00

aNumbers in parentheses are number of plots.bFrequency of overall budding and of grouse damage should be identicalbecause grouse are the only agents. Small differences are errors.

41


ANIMAL-DAMAGED DOUGLAS-FIR TREES AT DIFFER- ANIMAL-DAMAGED DOUGLAS-FIR TREE 0ENT ELEVATIONS IN WASHINGTON, YEARS 1-5 AFTER BY STOCK CLASS IN OREGON ANDPLANTING. WASHINGTON, YEARS 1-5 AFTER PLANT(mean annual percent) I NG.

Elevation, feet(mean annual percent)

0- 600- 1100- 1600- 2100- 2600- 3100- Stock class500 1000 1500 2000 2500 3000 3500 3600+ Mixed an

Damage (lO)a (8) (5) (9) (8) (2) (7) (0) 2-0 3-0 2-1 otheraDamage (108)b (22) (28) (7)

TYPEBarking 0.32 0.41 0.17 0.26 0.16 0.13 0.66 0.00 TYPEBrowsing Barking 0.14 0.45 0.09 0.36

Overall 21.39 24.59 28.52 15.27 15.66 3.17 3.47 0.00 BrowsingStem 14.65 16.42 19.28 11.34 11.43 2.44 2.84 0.00 Overall 22.71 17.35 18.42 37.71

Budding b Stem 19.24 13.24 14.69 26.58Overall 4.76 4.35 9.02 3.64 11.02 0.00 1.23 0.00 BuddingStem 2.08 1.92 2.31 2.49 4.46 0.00 0.88 0.00 Overall` 1.96 3.27 5.06 4.26

Clipping Stem 0.59 0.63 1.50 2.24Overall 12.68 7.17 10.54 1.91 11.81 0.40 6.34 0.00 ClippingStem 4.95 4.00 2.71 1.35 2.67 0.40 4.86 0.00 Overall 4.74 7.67 7.28 7.91

Root cutting 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Stem 2.79 3.52 2.60 3.40Pulling 0.06 0.03 0.00 0.02 0.00 0.00 0.00 0.00 Root cutting 0.01 0.12 0.02 0.00Trampling 0.15 0.33 0.59 0.15 0.38 0.00 0.09 0.00 Pulling 0.09 0.01 0.14 0.03Other 0.15 0.17 0.23 0.03 0.06 0.00 0.30 0.00 Trampling 0.17 0.41 0.31 0.39

All Damage 35.79 34.§2 42.44 20.50 32.83 3.57 11.66 0.00 Other 0.05 0.08 0.05 0.16

Stem Damage 21.75 22.8 24.93 15.17 18.57 2.85 9.22 0.00 All Damage 29.05 26.69 28.93 47.64

AGENTStem Damage 22.80 17.89 19.06 32.70

Deer 16.35 15.78 13.38 14.79 11.20 3.17 3.56 0.00 AGENTDomestic stock 0.00 0.07 0.00 0.00 0.00 0.00 0.00 0.00 Deer 20.85 13.33 15.29 24.03Elk 7.74 9.51 15.98 0.76 5.91 0.00 0.00 0.00 Domestic stock 0.01 0.00 0.00 0.08Gopherb 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Elk 2.14 4.40 3.77 17.25Grouse 4.76 4.37 9.08 3.67 11.02 0.00 1.53 0.00 Gopher 0.01 0.23 0.00 0.00Hare 9.71 3.70 6.54 0.89 11.81 0.13 1.80 0.00 Grousec 1.98 3.36 5.06 4.38Mountain beaver 2.93 3.64 4.02 0.54 0.00 0.13 0.03 0.00 Hare 3.51 5.57 6.88 2.90Microtine 0.11 0.00 0.00 0.05 0.03 0.13 0.10 0.00 Mountain beaver 1.14 0.85 0.15 4.31

Porcupine 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Microtine 0.03 0.04 0.04 0.00Other 0.08 0.10 0.10 0.44 0.00 0.00 4.47 0.00 Porcupine 0.00 0.00 0.00 0.00

Other 0.11 1.18 0.30 0.92


bFrequency of overall budding and of grouse damage should be identical

because grouse are the only agents. Small differences are errors.

a Principally 2-0 and 3-0, 2-0 and 2-1, or 1-1.


only agents. Small differences are errors.damage should be identical because grouse are the

CFrequency of overall budding and of grouse

42


ANIMAL-DAMAGED DOUGLAS-FIR PLOTS IN OREGON AND WASH- ANIMAL-DAMAGED PINEINGTON, YEARS 1-5 AFTER PLANTING. PLOTS IN OREGON AND WASH-(mean annual percent) INGTON, YEARS 1-5 AFTER

Damage

OREGON WASHINGTONCascade Cascade

Coast Moun- South- Coast Moun-Range tains west All Range tains(49)a (34) (33) (116) (24) (25)

BOTHAll STATES

(49) 165

PLANTING.(percent)

BOTH STATESDamage (29)a

TYPEBarkingBrowsing

OverallStem

Budding b

OverallStem

ClippingOverallStem

Root cuttingPullingTramplingOther

All DamageStem Damage

AGENTDeerDomestic stockElkGopherbGrouseHareMountain beaverMicrotinePorcupineOther

24.49 11.76 9.09 16.38 58.33 36.00 46.94 25.45

100.00 97.06 100.00 99.14 100.00 100.00 100.00 99.39100.00 94.12 96.97 97.41 100.00 100.00 100.00 98.19

18.37 67.65 48.48 41.38 87.50 52.00 69.39 49.704.08 26.47 6.06 11.21 79.17 40.00 59.18 25.45

89.80 88.24 51.52 41.38 91.67 52.00 59.39 49.7081.63 79.41 48.48 71.55 87.50 72.00 79.59 73.948.16 2.94 0.00 4.31 4.17 0.00 2.04 3.64

12.24 5.88 24.24 13.79 8.33 4.00 6.12 11.5238.78 41.18 15.15 32.76 62.50 20.00 40.82 35.1510.20 11.76 3.03 8.62 33.33 12.00 22.45 12.73

100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00100.00 100.00 96.97 99.14 100.00 100.00 100.00 99.39

97.96 97.06 100.00 98.28 87.50 96.00 91.84 96.364.08 5.88 3.03 4.31 4.17 0.00 2.04 3.64

22.45 2.94 27.27 18.10 45.83 12.00 28.57 21.214.08 5.88 3.03 4.31 4.17 0.00 2.04 3.64

18.37 70.59 51.52 43.10 87.50 52.00 69.39 50.9187.76 79.41 54.55 75.86 79.17 68.00 73.47 75.1532.65 23.53 9.09 23.28 45.83 16.00 30.61 25.452.04 2.94 6.06 3.45 12.50 12.00 12.24 6.060.00 0.00 0.00 0.00 0.00 0.00 0.00 0.008.16 8.82 0.00 6.03 25.00 20.00 22.45 10.91

a Numbers in parentheses are number of plots.bFrequency of overall budding and of grouse damage should be identical becausegrouse are the only agents. Small differences are errors.

TYPEBarkingBrowsing

37.93


Budding b


ClippingOverall 75.86Stem 75.86

Root cutting 17.24Pulling 31.03Trampling 48.28Other 3.45

All Damage 100.00Stem Damage 100.00

AGENT

Deer 96.55Domestic stock 48.28Elk 10.34Gopherb 44.83Grouse 6.90Hare 55.17Mountain beaver 0.00Microtine 0.00Porcupine 20.69Other 6.90

a Number in parentheses is number ofplots.

bFrequency of overall budding and ofgrouse damage should be identical becausegrouse are the only agents. Smalldifferences are errors.

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checklist of plants and animals

plantsDouglas-firJeffrey pinePonderosa pineWestern hemlock

animalsBand-tailed pigeonBlack bearBrush rabbitDeerDouglas squirrelElkJack-rabbitMountain beaverPocket gopherPorcupineSnowshoe hareSooty grouseVoleWoodrat

Pseudotsuga menziesii (Mirb.) FrancoPinus jeffreyi

Pinus ponderosa Laws.Tsuga heterophylla (Raf.) Sargent

Columba fasciataUrsus americanus

Sylvilagus bachmaniOdocoileus hemionusTamiascurus douglasii

Cervus canadensisLepus townsendii, L. californicus

Aplodontia rufaThomomys sp.

Erethizon dorsatumLepus americanus

Dendragapus obscurusClethrionomys occidentalis

Neotoma fuscipes

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Black, Hugh C., Edward Dimock II, James Evans, and JamesRochelle. 1979. Animal damage to coniferous plantations inOregon and Washington-Part I. A survey, 1963-1975. ForestResearch Laboratory, Oregon State University, Corvallis. ResearchBulletin 25. 44 p.Mammal and bird damage recorded on Douglas-fir and ponderosa pineplots-randomly established in Oregon and Washington during 1963-64, thenobserved for 5 to 10 years-was evaluated for impact on survival and growth.In all, 194 plots were installed, and 10 of the 110 seedlings on each plot werecaged to protect them from animals. All trees were examined after plantingand after bud burst each year for 5 years. A selected sample of 45 Douglas-firplots was observed another 5 years for long-term patterns and effects of severeplantation damage. Survival and growth were compared for caged and uncagedtrees. The agents, kind, amount, and distribution of animal damage wereevaluated by state, by subregion, and by relation to site features. Resultsindicate that stand damage in plantations exposed to heavy animal use,especially during seedling establishment, warrants expenditure for protectivemeasures.

KEYWORDS: height, survival, caging, Douglas-fir, ponderosa pine,


KEYWORDS: height, survival, caging, Douglas-fir, ponderosa pine.


KEYWORDS: height, survival, caging, Douglas-fir, ponderosa pine.

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animal damage to coniferous plantations in oregon and

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