VNLC senior botanists John Vollmar and Jake Schweitzer collaborated with the CNPS on this project involving the collection of vegetation data in support of classification and mapping of the southern Sierra Nevada Foothills eco-region. The study area encompasses over two million acres and extends from western Mariposa County south to eastern Kern County, within an elevation range of 500 to 4,000 feet.
Our team utilized climate data, DEMs, geologic maps, and aerial photography to distinguish the range of unique vegetation types within the region. Using our network of contacts within the ranching community in the region, we contacted landowners of targeted habitats in order to gain access to survey their properties. Over two spring and summer field seasons, our combined teams (VNLC and CNPS) surveyed and are currently processing over 700 relevé and rapid assessment vegetation plots from throughout the region. The plots encompassed the full range of habitats within the region, from riparian forest, to open grassland, to the many forms of chaparral and oak woodlands. At each plot, we collected detailed information pertaining to floristics as well as information related to geology and soils, slope and aspect, litter and thatch, level and nature of disturbances, observed wildlife use, and fire characteristics. The data will provide the foundation for the refinement of the Manual of California Vegetation (‘MCV’) classification system for the region. In turn, the classification will be used to produce a region-wide vegetation map with a minimum mapping unit of one acre. The map will provide baseline conditions for the detection of habitat changes related to disease, fire, climate change, and other environmental conditions. The map will also facilitate current analyses related to fuel loads and wildlife habitat.