Ecoregions denote areas of general similarity in ecosystems and in the
type, quality, and quantity of environmental resources. The ecoregions
of Alaska are a framework for organizing and interpreting
environmental data for State, national, and international level
inventory, monitoring, and research efforts.
The map and descriptions for 20 ecological regions were derived by
synthesizing information on the geographic distribution of
environmental factors such as climate, physiography, geology,
permafrost, soils, and vegetation. A qualitative assessment was used
to interpret the distributional patterns and relative importance of
these factors from place to place (Gallant and others, 1995). Numeric
identifiers assigned to the ecoregions are coordinated with those used
on the map of “Ecoregions of the Conterminous United States” (Omernik
1987, U.S. EPA 2010) as a continuation of efforts to map ecoregions
for the United States. Additionally, the ecoregions for Alaska and the
conterminous United States, along with ecological regions for Canada
(Wiken 1986) and Mexico, have been combined for maps at three
hierarchical levels for North America (Omernik 1995, Commission for
Environmental Cooperation, 1997, 2006). A Roman numeral hierarchical
scheme has been adopted for different levels of ecological regions.
Level I is the coarsest level, dividing North America into 15
ecological regions. Level II divides the continent into 50 regions. At
Level III, there are currently 182 ecological regions for North
America. Level IV ecoregions have been developed for the conterminous
United States, but Level III is the highest level available for
Alaska.
| Arctic Coastal Plain |
| Arctic Foothills |
| Seward Peninsula |
| Aleutian Islands |
| Brooks Range |
| Interior Forested Lowlands and Uplands |
| Interior Bottomlands |
| Yukon Flats |
| Ogilvie Mountains |
| Alaska Range |
| Copper Plateau |
| Wrangell Mountains |
| Ahklun and Kilbuck Mountains |
| Alaska Peninsula Mountains |
| Cook Inlet |
| Pacific Coastal Mountains |
| Coastal Western Hemlock-Sitka Spruce Forests |
The map and descriptions for 20 ecological regions were derived by
synthesizing information on the geographic distribution of environmental
factors such as climate, physiography, geology, permafrost, soils, and
vegetation. A qualitative assessment was used to interpret the
distributional patterns and relative importance of these factors from
place to place (Gallant and others, 1995). Numeric identifiers assigned
to the ecoregions are coordinated with those used on the map of
“Ecoregions of the Conterminous United States” (Omernik
1987, U.S. EPA 2010) as a continuation of efforts to map ecoregions for
the United States. Additionally, the ecoregions for Alaska and the
conterminous United States, along with ecological regions for Canada
(Wiken 1986) and Mexico, have been combined for maps at three
hierarchical levels for North America (Omernik 1995, Commission for
Environmental Cooperation, 1997, 2006). A Roman numeral hierarchical
scheme has been adopted for different levels of ecological regions.
Level I is the coarsest level, dividing North America into 15 ecological
regions. Level II divides the continent into 50 regions. At Level III,
there are currently 182 ecological regions for North America. Level IV
ecoregions have been developed for the conterminous United States, but
Level III is the highest level available for Alaska.