Ecoregions of Alaska, USA

Ecoregions are based on perceived patterns of a combination of causal and integrative factors including land use, land surface form, potential natural vegetation, and soils (Omernik, 1987). This map and descriptions of 20 ecological regions were derived by synthesizing information on the geographic distribution of environmental factors such as climate, terrain (including information on physiography, geology, glaciation, permafrost, and hydrologic features), soils, and vegetation. A qualitative assessment was used to interpret the distributional patterns and relative importance of these factors for influencing the character of the landscape from place to place.