Sonoran Creosote Bush Scrub

Background

Description and distribution  Description and distribution. Sonoran creosote bush scrub is the most widespread vegetation type in the Colorado Desert. It is dominated by creosote bush (Larrea tridentata). It characterizes the vast intermountain bajadas, reaching greatest development on coarse, well-drained soil with a total salinity of less than 0.02%. Creosote bush scrub occupies areas surrounding the Salton basin between the higher rocky hillsides and the desert saltbush community. The transition to desert saltbush occurs as the soil becomes heavier and the salt content increases to approximately 0.2%. The physiognomy of the Creosote Bush Scrub community is simple because of low species diversity and the broad spacing of the shrubs, 0.5 - 3 meters tall, usually with bare ground between. The codominant species in the community is burrobush, Ambrosia dumosa, a much shorter shrub varying from 20-60 cm. Many species of ephemeral herbs may flower in late winter/early spring if winter rains are sufficient. This is by far the dominant community in the Plan area, and the most susceptible to development. It is widespread on the valley floor and in the northeastern portion of the Plan area. Of the 405,785 acres of Sonoran Creosote Bush Scrub in the Plan area, 62% of the community currently occurs on public land or private conservation land, much of this in the northeastern portion of the Plan area. Associated covered species. Species that are associated with portions of this community are: Peninsular bighorn sheep, Palm Springs ground squirrel, Palm Springs pocket mouse, desert tortoise, burrowing owl, Coachella giant sand treader cricket, Coachella Valley grasshopper, Casey's June beetle, Coachella Valley milkvetch, triple ribbed milkvetch, Mecca aster, and Orocopia sage.