Sagebrush scrub
Sagebrush scrub is a vegetation type (biome) of mid to high elevation Western United States deserts characterized by low growing, drought resistant shrubs including sagebrush (Artemisia tridentata) and its associates.[1][2] It is the dominant vegetation type of the Great Basin Desert (Great Basin shrub steppe),[2] occurs along the margins of the Mojave Desert, including in the southern slopes of the Sierra Nevadas and Transverse Ranges of California,[2] and occurs in the Colorado Plateau and Canyonlands region, where it may be referred to as cool desert shrub.[3]
It often occurs adjacent to Pinyon-juniper woodland communities, between 4,000 and 7,000 feet elevation, and where annual precipitation is 8"-15", much falling as snow.[4]
Sometimes it occurs in pure stands of sagebrush, or with associates that vary from region to region.[2] Sagebrush scrub may occur as an understory of pinyon-juniper woodland.[2]
Mojave Desert
In the Mojave Desert, sagebrush associates include saltbrush (Atriplex spp.), rubber rabbitbrish (Ericameria nauseosa), green ephedra (Ephedra vidris), hot-sage (Grayia spinosa), and bitterbrush (Purshia glandulosa).[2]
Sierra Nevadas
Sagebrush scrub occurs in relatively deep soils along the Sierra-Cascade axis, running from Modoc County, CA to San Bernardino County, CA.[4]
In the Sierra Nevada range in California sagebrush associates include bitterbrush (Purshia tridentata), curl-leaf mountain-mahogany (Cercocarpus ledifolius), and rabbitbrushes (Chrysothamnus spp., Ericameria spp.).[1] Average summer temperatures are in the 80's Fahrenheit, and 10-20 degrees F in the winter.[1] It can survive on 7 inches of annual precipitation, so is generally below the Piñon-Juniper Woodland vegetation type, which requires 12 to 20 inches.[1] Its range is 4,200 to 7,000 feet in the Eastern Sierra Nevada range in California.[1]