Abstract
This map and accompanying descriptions were developed through participation with numerous individuals from federal and state agencies and non-governmental organizations using criteria defined in the National Hierarchical Framework of Ecological Units. Delineation generally involved the “top-down approach” of subdividing section level units. A “bottom-up approach” was used where landscape level units had been developed. Additional information is available on the process used for delineation of map units. Subsection maps were compiled at scales of 1:500,000 and 1:1,000,000, recompiled and joined at a scale of 1:1,000,000 and presented at a scale of 1:3,500,000.
Keywords
ecoregions,
ecological zones,
map,
continental United States
Citation
Cleland, D.T.; Freeouf, J.A.; Keys, J.E.; Nowacki, G.J.; Carpenter, C.A.; and McNab, W.H. 2007. Ecological Subregions: Sections and Subsections for the conterminous United States. Gen. Tech. Report WO-76D [Map on CD-ROM] (A.M. Sloan, cartographer). Washington, DC: U.S. Department of Agriculture, Forest Service, presentation scale 1:3,500,000; colored.