For classification of existing vegetation, a set of U.S. Forest Service standards and procedures has been established at the national and regional levels. The R5 CALVEG classification system conforms to the upper levels of the National Vegetation Classification Standard (USNVC) hierarchy as it currently exists. The USNVC sets guidelines for all federal agencies involved in this work. Lowest (floristic) levels of this hierarchy are currently being developed and have not yet been finalized for their applicability to California.
The Pacific Southwest Region (R5) Information Management staff is responsible for producing comprehensive spatial and tabular databases for existing vegetation, in addition to other duties. A mapping methodology has been developed to capture vegetation characteristics using automated, systematic procedures that efficiently and cost-effectively map large areas of the state with minimal bias and is supplemented with onsite field visits when appropriate. Map attributes consist of vegetation types using the CALVEG classification system and forest structural characteristics such as tree and shrub canopy cover and tree stem diameters.
Download Existing Vegetation Zones, Keys and Descriptions
In order to simplify the maintenance and publication of Existing Vegetation, we will no longer be offering spatial layers by tile, but rather by CALVEG zone. To reduce the size of the database and speed download times, these new zone-wide layers have been dissolved into "multi-part" features, where spatially separate polygons sharing the same attributes are stored as a single feature. In its entirety, a "single-part" format of one of these feature classes can potentially be more than 1,000,000 polygons. For analysis purposes, it is wise to select a smaller area of interest and break apart features using tools such as the "Multipart To Singlepart" tool in ArcGIS. Reference to this program does not serve as an endorsement by the USDA Forest Service for a specific product.