Watersheds versus Ecoregions for Environmental Assessment

landscape photo

MoRAP is attaching metrics generated from landcover to watershed and ecoregion polygons for the Glaciated Till Plains to test the validity of watersheds as a conservation assessment tool.
We showed that the same model for priority setting applied to different scales and types of polygons (large and small ecoregion and watershed polygons) result in different priority areas, and that land type association (ecoregion) polygons circumscribe more uniform landscapes in terms of landcover than 10-digit hydrologic unit (watershed) polygons. Smaller subdivisions of a landscape are more uniform than larger ones, so all else being equal, assessments using the smallest available uniform polygon coverage should result in the most spatially specific set of conservation priorities.