Jepson ecoregions of California, USA

This layer delineates the geographic subdivisions of California defined for The Jepson Manual: Higher Plants of California (Hickman, 1993). These regions were developed for the Jepson flora to aid in describing where plant species were known to occur. The regions were defined by natural features, including broadly defined vegetation types, and geologic, topographic, and climatic variation. The Flora authors relied heavily on the Potential Natural Vegetation map of Küchler (1977) in delineating regions. The Flora included only a page-size representation of the map of three provinces, subdivided into ten regions, but also provided geographic descriptions of the boundaries between regions and subregions. Based on these descriptions, the Biogeography Lab digitized the boundaries of the ten regions using 1990 Landsat imagery and ancillary digital data at a 1:100,000 map scale. These regions were used for compiling and analyzing the California Gap Analysis databas