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S_USA.PNV_2000Sections

The Potential Natural Vegetation (PNV) 2000 feature class contains ecological section polygons attributed with PNV group to show the relationships between ECOMAP 2007 and potential natural vegetation groups developed through coarse-scale mapping for wildland fire and fuel management (USDA-FS, 2002). The EcomapSections 2007 data set describes the ecological sections within the conterminous United States. It contains regional geographic delineations for analysis of ecological relationships across ecological units. ECOMAP is the term used for a USDA Forest Service initiative to map ecological units and encourage their use in ecosystem-based approaches to forest land conservation and management. This is a collaborative effort with many partners. It is coordinated at the national and regional levels by USDA Forest Service staff and implemented in cooperation with State forestry agencies and others. ECOMAP mapping criteria are outlined in the National Hierarchical Framework of Ecological Units (https://www.ncrs.fs.fed.us/gla/reports/hierarchy.htm). The framework systematically divides the country into progressively smaller areas of land and water that have similar physical and biological characteristics and ecological processes.