- Metric Name:  Herbaceous Cover Change

- Data Vintage:  2020

- Unit Of Measure: Percent

A raster dataset representing absolute change of herbaceous fractional (%) land cover in the Southern California Region.

Creation Method: Absolute change was calculated for annual and perennial grasses and forbs and litter, called “herbaceous” vegetation, using five-year-averages for 1986-1990 and 2016-2019 with data from the Rangeland Analysis Platform (RAP). Absolute Change = (2016 - 2020 Average) - (1986-1990 Average)

In areas where herbaceous cover increased over this period, values will be positive (up to 60%); where herbaceous cover decreased, values will be negative (down to -60%). These data may be used as an indicator of vegetation type conversion resulting from high fire frequency or other disturbances.

These data only represent herbaceous cover; therefore, a second layer of information is required to determine what the cover changed to in areas that experienced a decrease in herbaceous cover over the time period examined.

The Rangeland Analysis Platform (RAP) was created in collaboration with the U.S. Department of Agriculture’s Natural Resources Conservation Service, the Department of Interior’s Bureau of Land Management, and the University of Montana to map western United States rangelands. The data can be used by landowners, managers, conservationists, and scientists to inform land management, planning, decision making, and evaluation of outcomes. For more information about RAP, please refer to the website: https://rangelands.app/

RAP fractional (percent) cover maps are produced by combining field plots from the Bureau of Land Management (BLM) Assessment, Inventory, and Monitoring (AIM) datasets and National Resources Conservation Service (NRCS) National Resources Inventory (NRI) with the historical Landsat satellite record. Due to a low amount of field points collected in the CWC focus area, the data products should be used alongside local knowledge and site-specific data to inform actions and decision making. To learn more about how RAP maps and data are intended to be used, refer to this site: https://support.rangelands.app/article/46-new-to-rap-start-here-landing

- Credits:  San Diego State University CWC Project Team

San Diego State University’s Connecting Wildlands and Communities Project Team: 
Data disclaimer:  
The user accepts sole responsibility for the correct interpretation and use of the data provided.