LANDFIRE data products are designed to facilitate national- and regional-level strategic planning and reporting of management activities. Data products are created at a 30-meter grid spatial resolution raster data set. Original ca 2001 products were developed and served in 2004 and have been updated with a number of “biennial updates” representing conditions in 2008, 2010, and 2012. Principal uses of the data products include providing national-level, landscape-scale geospatial products to support fire, fuels, and vegetation management planning. The LANDFIRE existing vegetation layers describe the following elements of existing vegetation for each LANDFIRE mapping zone: existing vegetation type, existing vegetation canopy cover, and existing vegetation height. Vegetation is mapped using predictive landscape models based on extensive field reference data, satellite imagery, biophysical gradient layers, and classification and regression trees. The existing vegetation type (EVT) data layer generally represents the current distribution of the terrestrial ecological systems classification developed by NatureServe for the western Hemisphere.
Results/Conclusions
In areas where agricultural, urban, or ruderal vegetation predominates, the EVT legend and resulting layer deviates from Ecological System units and is described and mapped using a combination of other map products, including NLCD2001, National Agricultural Statistical Service Cropland Data Layer, Conservation Reserve Program data, and conservation easement data. These map units are broad and generally emphasize life-form, leaf-form, and general crop type but were inconsistent in their resolution and applied across large geographic areas. In order to enhance the thematic resolution of these map units and to tier more directly to the National Vegetation Classification, we have developed new EVT map units for ruderal vegetation The new map units still emphasize life-form and leaf-form but are consistently stratified into geographic areas in order to better capture relevant ecological information. Diagnostic and descriptive characteristics have also been developed in order to identify map units for all available plot data for the project. In addition, mapping criteria have been developed to portray the map units more accurately spatially on upcoming LANDFIRE products.