Composite conditions for the sagebrush group

Habitat abundance (lower left), habitat risk (lower right), and composite conditions (top center) for the sagebrush group of species in watersheds of the Great Basin. For habitat abundance, 1 = low (<25 percent of the watershed is habitat), 2 = moderate (25-50 percent of the watershed is habitat), and 3 = high (> 50 percent of the watershed is habitat). For the map of habitat risk, 1 = watersheds with habitats dominated by none-low risk of displacement by cheatgrass, 2 = watersheds with habitats dominated by low-moderate risk, and 3 = watersheds with habitats dominated by moderate-high risk. For the map of composite habitat conditions, the first number is for abundance, and the second number is for risk, using the definitions above for maps of habitat abundance and risk. For example, 1-1 denotes watersheds with habitats of low abundance and none-low risk, whereas 3-3 denotes watersheds of high habitat abundance and moderate-high risk. Map colors on the composite map follow those for the map of habitat risk (blue = moderate-high risk, green = low-moderate risk, and brown = none-low risk), and intensity of colors follows those for the map of habitat abundance (darkest shade = high habitat abundance, intermediate = moderate, and lightest = low) (from Wisdom and others 2005a). Mean size of the 367 watersheds that occur entirely within the ecoregion boundaries is 66, 000 ha. Habitat conditions at the watershed level for the sagebrush group of species (terrestrial vertebrates) are shown in 3 maps. The lower left map depicts habitat abundance in three classes; the lower right map depicts habitat risk in 3 classes. The upper map depicts the spatial arrangement of the nine possible habitat abundance-risk combinations. Habitat is most abundant in the central and northern portions of the ecoregion for this group, whereas habitat is at lowest risk in the western third and in scattered watersheds throughout. The best combination- high abundance and low risk- occurs in a small area along the northern edge of the ecoregion. The worst combination- low abundance and high risk- occurs in scattered patches along the eastern and western edges of the ecoregion.