Terrestrial and aquatic species use Michigan's spatial landscapes in significantly different ways. Thus, the WAP presents aquatic and terrestrial landscape feature data within two different but overlapping ecological frameworks.

The ecological framework for aquatic landscape features is defined by the four Great Lakes drainage basins (Lake Erie, Lake Huron, Lake Michigan and Lake Superior) within the State (DNR 2005a; Fig. 1). The DNR and other agencies currently use this framework for planning, research and management activities. It also corresponds to conservation activities being conducted at the watershed scale within these lake basins.

The ecological framework for terrestrial landscape features is defined by Albert (1995; Fig. 2). The ecoregions identified by this framework are similar to those defined by Bailey et al. (1980). Again, many conservation partners in Michigan are already using this framework, and the DNR is using it to direct ongoing ecoregional planning activities.