Bailey's ecoregions and subregions of the United States, Puerto Rico, and the U.S. Virgin Islands

This map is commonly called Bailey's ecoregions and shows ecosystems of regional extent in the United States, Puerto Rico, and the U.S. Virgin Islands, based on conditions in 1994. Four levels of detail are included to show a hierarchy of ecosystems. The largest ecosystems are domains, which are groups of related climates and which are differentiated based on precipitation and temperature. Divisions represent the climates within domains and are differentiated based on precipitation levels and patterns as well as temperature. Divisions are subdivided into provinces, which are differentiated based on vegetation or other natural land covers. The finest level of detail is described by subregions, called sections, which are subdivisions of provinces based on terrain features. Also identified are mountainous areas that exhibit different ecological zones based on elevation. Also included are maps of the Bailey Ecoregions of the United States in multiple formats and sizes.