STRATIFICATIONPLOT PLACEMENT

CONTROLS

Strategy for Monitoring Post-fire Rehabilitation Treatments

Troy Wirth and David PykeTroy Wirth and David PykeUSGS – Biological Resources DivisionUSGS – Biological Resources DivisionForest and Rangeland Ecosystem Science CenterForest and Rangeland Ecosystem Science CenterCorvallis, OregonCorvallis, Oregon

U.S. Department of InteriorU.S. Geological Survey

Supported by USGS - BLM Interagency Agreement #HAI040045

Monitoring ApproachMonitoring Approach

ObjectivesObjectives StratificationStratification Control PlotsControl Plots Random SamplingRandom Sampling Data QualityData Quality Statistical AnalysisStatistical Analysis Repeatable, objective field methods Repeatable, objective field methods

using Rangeland Monitoring Databaseusing Rangeland Monitoring Database

StratificationStratification

Division of treatment areas into defined Division of treatment areas into defined monitoring unitsmonitoring units with similar characteristics with similar characteristics

Decreases variability, increases precisionDecreases variability, increases precision Data collected is then inferred to be Data collected is then inferred to be

representative of the entire monitoring representative of the entire monitoring unit.unit.

Stratification into monitoring units helps to Stratification into monitoring units helps to determine success at the project level - determine success at the project level - and eventually at a regional scaleand eventually at a regional scale

StratificationStratification

Monitoring Units may vary across the Monitoring Units may vary across the landscape and be separated by other landscape and be separated by other monitoring units.monitoring units.

From Herrick et al 2005b

Stratification Stratification Background InformationBackground Information

Aerial photographsAerial photographs Soil SurveysSoil Surveys

Determine what mapping units cover the Determine what mapping units cover the treatment areatreatment area

Can you identify the soil series within the Can you identify the soil series within the mapping units?mapping units?

What ecological sites are within the mapping What ecological sites are within the mapping units?units?

How do you determine the ecological sites?How do you determine the ecological sites?

Stratification Stratification Background InformationBackground Information

GIS LayersGIS Layers Digital Elevation Model (DEM’s)Digital Elevation Model (DEM’s) Land management activities (grazing Land management activities (grazing

allotments, previous seedings and fires etc.)allotments, previous seedings and fires etc.) Fire and treatment perimeters for current Fire and treatment perimeters for current

projectproject SoilsSoils Roads, streams and other geographic Roads, streams and other geographic

features that would be avoidedfeatures that would be avoided

Stratification Stratification Background Information - ResourcesBackground Information - Resources

Web Soil Survey Web Soil Survey http://websoilsurvey.nrcs.usda.gov/ahttp://websoilsurvey.nrcs.usda.gov/app/pp/

Soil Data Mart Soil Data Mart http://soildatamart.nrcs.usda.gov/Dehttp://soildatamart.nrcs.usda.gov/Default.aspxfault.aspx

USGS Seamless Data Distribution USGS Seamless Data Distribution http://seamless.usgs.gov/http://seamless.usgs.gov/

Official Soil Series Descriptions Official Soil Series Descriptions http://soils.usda.gov/technical/classifhttp://soils.usda.gov/technical/classification/osd/index.htmlication/osd/index.html

Stratification Stratification Identifying Ecological SitesIdentifying Ecological Sites

Each plot must have Ecol. Site identifiedEach plot must have Ecol. Site identified Not all Monitoring Units are defined by one Ecol Site.Not all Monitoring Units are defined by one Ecol Site. An ecological site is a “distinctive kind of land with An ecological site is a “distinctive kind of land with

specific characteristics that differs from other kinds of specific characteristics that differs from other kinds of land in its ability to produce a distinctive kind and land in its ability to produce a distinctive kind and amount of vegetation” (NRCS).amount of vegetation” (NRCS).

Consist of site characteristics, plant Consist of site characteristics, plant communities, site interpretations, and communities, site interpretations, and supporting informationsupporting information

Identify ecological sites using soil and landform Identify ecological sites using soil and landform indicators (soil surveys)indicators (soil surveys)

Soil mapsSoil maps

Soils are grouped into soil mapping Soils are grouped into soil mapping units because we often cannot map units because we often cannot map soils at the scale at which they occursoils at the scale at which they occur

Soil map unitSoil map unit: includes one or more : includes one or more dominant dominant soilsoil map unit componentsmap unit components + + inclusions (minor map unit components)inclusions (minor map unit components)

Soil map unit Soil map unit componentcomponent: soil series + : soil series + slope and surface texture modifierslope and surface texture modifier

A soil map unit can be:A soil map unit can be:

An An ASSOCIATIONASSOCIATION of two or more soils of two or more soils that occur in a repetitive and that occur in a repetitive and predictablepredictable pattern (e.g. low ridges & swales)pattern (e.g. low ridges & swales)

A A COMPLEXCOMPLEX of two or more soils that of two or more soils that usually do not occur in a usually do not occur in a predictablepredictable pattern at a mappable scale (e.g. coarse pattern at a mappable scale (e.g. coarse and fine soils in a river floodplain)and fine soils in a river floodplain)

A single soil series (but even these map A single soil series (but even these map units usually have “inclusions” too small to units usually have “inclusions” too small to be mapped). Sometimes call a be mapped). Sometimes call a CONSOCIATIONCONSOCIATION

Using soils to identify ecological sitesUsing soils to identify ecological sites

An An ecological siteecological site can include more than one can include more than one soil series, provided that the soils are similarsoil series, provided that the soils are similar

A A soil map unitsoil map unit can include more than one can include more than one ecological site. Soil map units often include ecological site. Soil map units often include many different soils, with different potentials many different soils, with different potentials to support plant communitiesto support plant communities

Even a Even a soil seriessoil series can include more than one can include more than one ecological site. Soil surface texture often ecological site. Soil surface texture often varies within a soil series. Soil surface texture varies within a soil series. Soil surface texture is very important in distinguishing ecological is very important in distinguishing ecological sites.sites.

Stratification Stratification Identifying Ecological SitesIdentifying Ecological Sites

Determine soil Determine soil mapping unitmapping unit

Examine soil Examine soil mapping unit mapping unit description (220)description (220)

Determine soil Determine soil series within series within mapping unit.mapping unit.

Stratification Stratification Identifying Ecological SitesIdentifying Ecological Sites

Dig soil pits to identify soil series and associated ecological sites

Ninemile and Carvix Soil Series

Stratification Stratification Identifying Ecological SitesIdentifying Ecological Sites

Stratification CriteriaStratification Criteria

Treatment typeTreatment type Soil type / ecological siteSoil type / ecological site Slope / aspect / elevationSlope / aspect / elevation Multiple polygons/ minimum sizeMultiple polygons/ minimum size Each stratification criteria doubles number Each stratification criteria doubles number

of monitoring units (if all are monitored)of monitoring units (if all are monitored) What criteria will reduce variability the What criteria will reduce variability the

most?most?

Example Stratification Example Stratification Treatment perimeter and DEMTreatment perimeter and DEM

Example StratificationExample StratificationTreatment perimeter with slope reclassificationTreatment perimeter with slope reclassification

Example Stratification Example Stratification Treatment perimeter with slopes < & > 15% slopeTreatment perimeter with slopes < & > 15% slope

Example Stratification Example Stratification Soil mapping unitsSoil mapping units

Example Stratification Example Stratification Soil mapping units within treatment perimeterSoil mapping units within treatment perimeter

Example Stratification Example Stratification Sample AreasSample Areas

121 Mcpan-Chijer complex

181 Starbuck- Mcpan-rock outcrop

Random SamplingRandom Sampling

Enables statistical inference to the Enables statistical inference to the monitoring unitmonitoring unit

GIS or traditional map gridGIS or traditional map grid Can use several types of random sampling Can use several types of random sampling

(simple, stratified, and two-stage random (simple, stratified, and two-stage random sampling)sampling)

Establish rejection criteria Establish rejection criteria (slopes/roads/streams/rocks etc..)(slopes/roads/streams/rocks etc..)

Random Point GenerationRandom Point GenerationHawth’s Tools FeaturesHawth’s Tools Features

Input layer (polygon/raster)Input layer (polygon/raster) Minimum distance between pointsMinimum distance between points Stratified – (number of points)Stratified – (number of points) Stratified designStratified design

Polygon unique idPolygon unique id Number of points per polygonNumber of points per polygon Density of points per polygonDensity of points per polygon

Hawth’s Tools Main Screen

1. Generate Random points

• Use for determining random plot locations

2. Generate Regular points

• Other uses including separating polygons into roughly equal sizes

Example Stratification (simple)Example Stratification (simple)Random point generation screenRandom point generation screen

ControlsControls Was rehabilitation necessary?Was rehabilitation necessary? Plots that receive no treatment Plots that receive no treatment

No seed No seed No soil surface disturbance (affects bare No soil surface disturbance (affects bare

ground and annual exotic abundance)ground and annual exotic abundance) Randomly place within monitoring unit Randomly place within monitoring unit

prior to treatment implementationprior to treatment implementation If controls are not possible, quantitative If controls are not possible, quantitative

standards must be specifiedstandards must be specified

ControlsControls

Long-term monitoring – controls are highly Long-term monitoring – controls are highly valuable valuable May not be able to distinguish between May not be able to distinguish between

seeded and unseeded plantsseeded and unseeded plants Help to determine persistence of seedingHelp to determine persistence of seeding

Helps to determine treatment effectHelps to determine treatment effect Provides a measure of natural recoveryProvides a measure of natural recovery