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Map Layer Info

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

What this map layer shows:

Ecoregions defined by common climatic and vegetation characteristics, shown as domains, divisions, provinces and sections.
opens the USDA Forest Service home page
Background Information
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Ecoregions are ecosystems of regional extent. Bailey's ecoregions distinguish areas that share common climatic and vegetation characteristics. A four-level hierarchy is used to differentiate the ecoregions, with the broadest classification being the domain. Domains are groups of related climates and are differentiated based on precipitation and temperature. There are four domains used for worldwide ecoregion classification and all four appear in the United States: the polar domain, the humid temperate domain, the dry domain, and the humid tropical domain. 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. Mountainous areas that exhibit different ecological zones based on elevation are identified at the province level. The finest level of detail is described by subregions, called sections, which are subdivisions of provinces based on terrain features.

The purpose of ecological land classification is to provide information for both the development of resources and the conservation of the environment. Government and private land managers use this information to estimate ecosystem productivity, to determine probable responses to land management practices, and to address environmental issues over large areas, such as air pollution, forest disease, or threats to biodiversity. This map layer was compiled by the USDA Forest Service.

The Bailey's Ecoregions and Subregions of the United States, Puerto Rico, and the U.S. Virgin Islands map layer shows the ecoregion domains, divisions, provinces, and sections for this area. Further information on domains, divisions, and provinces is available from the USDA Forest Service Rocky Mountain Research Station page describing Ecoregions of the United States, and detailed information on sections is available through the USDA Forest Service page, Ecological Subregions of the United States.

The National Atlas also includes a map layer showing Omernik's Level III Ecoregions, which are defined by a wide variety of characteristics, including vegetation, animal life, geology, soils, water, climate, and human land use, as well as other living and non-living ecosystem components.


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Ecoregions - Bailey