Vernal Pools of Southern California: Draft Recovery Plan

摘要

Following winter rainstorms, vernal pools form in depressions above an impervoussoil layer or layers. Water evaporates from these pools during the spring and early summer. Vegetation communities associated with vernal pools in southern California are valley needlegrass grassland, coastal sage scrub, maritime succulent scrub, and chaparral. In San Diego County, loss of vernal pool habitat is estimated at 95 to 97 percent and nearly total in Los Angeles, Riverside, Ventura, and Orange Counties. Soil alteration surrounding vernal pools, vegetation, drainage patterns, and hydrology can have profound adverse effects on vernal pool organisms by affecting the hydrological regime of the pools and the quality of water.