Table 1.

Scope, resolution, and size of conservation databases

Database	Spatial extent	Resolution	Sites	Species	Species records	Potential surrogate species
Coastal sage scrub	Part of southern California	25 km2 grid squares	785	277	3,197	62
Columbia Plateau	Portions of five states	U.S. Geological Society sixth  Hydrologic Unit Classification	1,241	211	4,527	83
Environmental Protection Agency by county	U.S. except Hawaii	Counties	2,856	749	10,822	56

Resolution column indicates how “sites” in each database were defined. Species definitions are as per the databases; they include species, subspecies, and variants. A species record indicates the known presence of a population of a species at a site. Subwatersheds are defined based on physiography and hydrology, and are used by federal agencies as land management units.