干旱区生态环境知识资源中心

Land managers and scientists need context in which to interpolate between or extrapolate beyond discrete field points in space and time. Ecological classification of land (ECL) is one way by which these relationships can be made. Until regional issues emerged and calls were made for ecosystem management (EM), each land management institution chose its own ECLs. The need for economic efficiency and the increasing availability of geographic information systems (GIS) compel the creation of a national ECL so that communication across ownership boundaries can occur. ECOMAP an 8-level, top-down, nested, hierarchical, multivariable approach designed to solve this problem has been endorsed by the Federal Geographic Data Committee. While the coarsest, upper 4 levels of ECOMAP have been produced for the entire U.S., the task of completing the 4 finer-grained levels has been left to local practitioners. We tried to apply the suggestions of ECOMAP for completing an ECL for a 4.5-million-hectare area centered in western Utah. Due to the lack of complete and consistent sets of spatial databases suggested as necessary by ECOMAP for completing the ECL for this area, we developed alternatives to complete the ECL using extant information. We stressed 1 dominant landscape feature per hierarchical level, using repeatable protocols to identify landscape units. We added 2 additional levels below the 8 suggested by ECOMAP Ecological sites (ESs), the 9th level, are designed to overcome the nestedness of ECOMAP that we found prevented us from using important data on ESs already available from the Natural Resources Conservation Service. Vegetation stands (VSs), the 10th and finest-grain level, are subdivisions of individual polygons of ESs based on differences in disturbance histories that have led to differing current vegetation structure and composition. The ECL we created should help federal, state, and private land managers in western Utah more easily communicate about issues that cross ownership boundaries.