"Shrub-steppe"is a nonforested vegetation type consisting of one or more layers of perennial bunchgrasses and a conspicuous but discontinuous layer of shrubs (see Eastside Steppe for sites with little or no shrub cover). Although Big Sagebrush (Artemisia tridentata) is the most widespread shrub-steppe shrub, other dominant (or co-dominant) shrubs include Antelope Bitterbrush (Purshia tridentata), Threetip Sagebrush (A. tripartita), Scabland Sagebrush (A. rigida), and Dwarf Sagebrush (A. arbuscula). Dominant bunchgrasses include (but are not limited to) Idaho fescue (Festuca idahoensis), Bluebunch Wheatgrass (Pseudoroegneria spicata), Sandberg Bluegrass (Poa secunda), Thurber's Needlegrass (Achnatherum thurberianum), and Needle-and-Thread (Hesperostipa comata). In areas with greater precipitation or on soils with higher moisture-holding capacity, shrub-steppe can also support a dense layer of forbs (i.e., broadleaf herbaceous flora). Shrub-steppe contains various habitat features, including diverse topography, riparian areas, and canyons. Another important component is habitat quality (i.e., degree to which a tract resembles a site potential natural community), which may be influenced by soil condition and erosion; and the distribution, coverage, and vigor of native shrubs, forbs, and grasses. Sites with less disturbed soils often have a layer of algae, mosses, or lichens. At some more disturbed sites, non-natives such as Cheatgrass (Bromus tectorum) or Crested Wheatgrass (Agropyron cristatum) may be co-dominant species. Fire disturbance is an ecological component of shrub-steppe. Shrub-steppe disturbed by fire may lack the aforementioned habitat components during periods of post-fire recovery.
(Ord. 2021-016, 2021; Ord. 2025-006, 7/1/2025)