Ecoregions of the conterminous United States

Map

Transfer Guideline: Recommendation

A map of ecoregions of the conterminous United States has been compiled to assist managers of aquatic and terrestrial resources in understanding the regional patterns of the realistically attainable quality of these resources. The 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. A synoptic approach similar to that used to define these ecoregions is also useful for applications of the map. Initial efforts to use the framework are at the state level of resource management; they center on aquatic ecosystems - mainly attainable ranges in chemical quality, biotic assemblages, and lake trophic state. Ecoregion maps (EPA Level III) are used by the Native Seed Network (NSN, http://www.nativeseednetwork.org/article_view?id=27) to guide transfers. They recommend that in the absence of genetic information, this level of mapping offer a practical guide for seed transfer zone boundaries.