Download Bailey`s Ecoregions and Subregions of the United States, Puerto

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.
Background Information
Sample Map
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 Inventory and Monitoring Institute 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.