ALLUVIAL FAN SAGE SCRUB
Alluvial fan sage scrub is a sub-type of coastal sage scrub found on the alluvial fans and flood plains of the coastal side of the San Bernardino and San Gabriel Mountains. All remaining significant expanses of alluvial fan sage scrub habitats now occur only in San Bernardino County, specifically on the Etiwanda Fan, Lytle Creek, Cajon Creek and the Santa Ana River. The climatic features of alluvial fan sage scrub are similar to those for Coastal Sage Scrub, but differ in the frequency and intensity of surface flooding that occurs within the habitat. The soil is a complex, unsorted structure of alluvium composed of boulders, rocks and sands. The vegetation is less dense than that of coastal sage scrub when it occurs in river channels where it is subject to frequent flooding. The primary indicator plant for alluvial fan sage scrub is Scale-broom (Lepidospartum squamatum). Alluvial Fan Sage Scrub Communities have been severely altered by flood control activities that circumvent the periodic flooding necessary to maintain the habitat, leading to the gradual type conversion of this unique community type. The State of California considers Alluvial Fan Sage Scrub to be a very threatened and rare natural community.