STRATIFICATION PLOT PLACEMENT CONTROLS Strategy for Monitoring Post-fire Rehabilitation Treatments

1. STRATIFICATIONPLOT PLACEMENTCONTROLSStrategy for Monitoring Post-fire Rehabilitation Treatments Troy Wirth and David Pyke USGS – Biological Resources Division Forest and Rangeland Ecosystem Science Center Corvallis, Oregon U.S. Department of Interior U.S. Geological Survey Supported by USGS - BLM Interagency Agreement #HAI040045

2. Monitoring Approach • Objectives • Stratification • Control Plots • Random Sampling • Data Quality • Statistical Analysis • Repeatable, objective field methods using Rangeland Monitoring Database

3. Stratification • Division of treatment areas into defined monitoring units with similar characteristics • Decreases variability, increases precision • Data collected is then inferred to be representative of the entire monitoring unit. • Stratification into monitoring units helps to determine success at the project level - and eventually at a regional scale

4. Stratification • Monitoring Units may vary across the landscape and be separated by other monitoring units. From Herrick et al 2005b

5. Stratification Background Information • Aerial photographs • Soil Surveys • Determine what mapping units cover the treatment area • Can you identify the soil series within the mapping units? • What ecological sites are within the mapping units? • How do you determine the ecological sites?

6. Stratification Background Information • GIS Layers • Digital Elevation Model (DEM’s) • Land management activities (grazing allotments, previous seedings and fires etc.) • Fire and treatment perimeters for current project • Soils • Roads, streams and other geographic features that would be avoided

7. Stratification Background Information - Resources • Web Soil Survey http://websoilsurvey.nrcs.usda.gov/app/ • Soil Data Mart http://soildatamart.nrcs.usda.gov/Default.aspx • USGS Seamless Data Distribution http://seamless.usgs.gov/ • Official Soil Series Descriptions http://soils.usda.gov/technical/classification/osd/index.html

8. Stratification Identifying Ecological Sites • Each plot must have Ecol. Site identified • Not all Monitoring Units are defined by one Ecol Site. • An ecological site is a “distinctive kind of land with specific characteristics that differs from other kinds of land in its ability to produce a distinctive kind and amount of vegetation” (NRCS). • Consist of site characteristics, plant communities, site interpretations, and supporting information • Identify ecological sites using soil and landform indicators (soil surveys)

9. Soil maps • Soils are grouped into soil mapping units because we often cannot map soils at the scale at which they occur • Soil map unit: includes one or more dominant soilmap unit components + inclusions (minor map unit components) • Soil map unit component: soil series + slope and surface texture modifier

10. A soil map unit can be: • An ASSOCIATION of two or more soils that occur in a repetitive and predictable pattern (e.g. low ridges & swales) • A COMPLEX of two or more soils that usually do not occur in a predictable pattern at a mappable scale (e.g. coarse and fine soils in a river floodplain) • A single soil series (but even these map units usually have “inclusions” too small to be mapped). Sometimes call a CONSOCIATION

11. Using soils to identify ecological sites • An ecological site can include more than one soil series, provided that the soils are similar • A soil map unit can include more than one ecological site. Soil map units often include many different soils, with different potentials to support plant communities • Even a soil seriescan include more than one ecological site. Soil surface texture often varies within a soil series. Soil surface texture is very important in distinguishing ecological sites.

12. Stratification Identifying Ecological Sites • Determine soil mapping unit • Examine soil mapping unit description (220) • Determine soil series within mapping unit.

13. Stratification Identifying Ecological Sites Ninemile and Carvix Soil Series Dig soil pits to identify soil series and associated ecological sites

15. Stratification Identifying Ecological Sites

16. Stratification Criteria • Treatment type • Soil type / ecological site • Slope / aspect / elevation • Multiple polygons/ minimum size • Each stratification criteria doubles number of monitoring units (if all are monitored) • What criteria will reduce variability the most?

17. Example Stratification Treatment perimeter and DEM

18. Example StratificationTreatment perimeter with slope reclassification

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

20. Example Stratification Soil mapping units

21. Example Stratification Soil mapping units within treatment perimeter

22. Example Stratification Sample Areas 121 Mcpan-Chijer complex 181 Starbuck- Mcpan-rock outcrop

23. Random Sampling • Enables statistical inference to the monitoring unit • GIS or traditional map grid • Can use several types of random sampling (simple, stratified, and two-stage random sampling) • Establish rejection criteria (slopes/roads/streams/rocks etc..)

24. Random Point GenerationHawth’s Tools Features • Input layer (polygon/raster) • Minimum distance between points • Stratified – (number of points) • Stratified design • Polygon unique id • Number of points per polygon • Density of points per polygon

26. Hawth’s Tools Main Screen • 1. Generate Random points • Use for determining random plot locations • Generate Regular points • Other uses including separating polygons into roughly equal sizes

27. Example Stratification (simple)Random point generation screen

29. Controls • Was rehabilitation necessary? • Plots that receive no treatment • No seed • No soil surface disturbance (affects bare ground and annual exotic abundance) • Randomly place within monitoring unit prior to treatment implementation • If controls are not possible, quantitative standards must be specified

30. Controls • Long-term monitoring – controls are highly valuable • May not be able to distinguish between seeded and unseeded plants • Help to determine persistence of seeding • Helps to determine treatment effect • Provides a measure of natural recovery