Potential natural vegetation in the 17 conterminous western United States

Kuchler and Bailey constructed continental scale maps of the vegetation of the United States. These maps are compared for the 17 Western United States. The vegetation categories (vegetation types for Kuchler and ecoregions for Bailey) are quantified by category and by state with particular emphasis on shrub vegetation categories. The Kuchler map has 30 shrub vegetation types (including pinyon-juniper shrub mosaics) that account for about 40 percent (1.8 x 10(6) km(2)) of the area in the 17 states. In the Bailey map, 15 ecoregions account for about 34 percent (1.6 x 10(6) km(2)) of the area in shrublands.