Flicker Ridge
Map SatelliteThis ridge and the adjacent valleys have long served as an outdoor classroom and research area for plant succession and ecological studies.
A number of plant communities are found in the relatively small area including the only closed-cone pine – in this instance, knobcone pine, Pinus attenuata – forest in the Berkeley Hills. These pines occur on the ridge top as do several patches of dwarf redwoods, Sequoia sempervirens, some of them 50 years of age and only 2.6 meters (8 feet) tall.
Redwood forests occupy portions of the northeast-facing slopes and valley bottoms as do the oak-madrone-bay woodlands and the bay, Umbellularia californica, woodlands. The latter is probably the climatic climax vegetation in the Berkeley Hills; however as they require a long absence of fire, the stands are not extensive.
Other communities include chaparral, introduced and native grasslands; the latter includes Festuca idahoensis and several native flowers and is found in the southeastern corner of the area. Baccharis pilularis is common and is dominant in several areas.
Plant succession, fire effects, microclimatic variation, differential weathering and soil formation (on opposing ridge slopes) are well illustrated.
There is an abundance of wildlife in the area, including an occasional golden eagle, Aquila chrysaetos.
Geological features include a variety of formations; a nearly vertical strata of mid-Miocene Claremont formation of siliceous shale and opaline chert is flanked by the Mio-Pliocene Orinda formation, the Lower Pliocene Grizzly Peak formation and the Cretaceous Redwood Canyon Formation.
Integrity: Grazing on lower flank in Indian Valley, jeep road, railroad grade, powerlines and abandoned squatter huts, but most of ridge area relatively undisturbed. Threat of development in Indian Valley which could have adverse impact on ridge through trespass.
Use: Research, field laboratory.
Ref: Rademacher, K. A., 1973. Evolution of the Landscape in the Flicker Ridge Area, Contra Costa County, California: A Physical Geography, M. A. Thesis in Geography, University of California, Berkeley.
January 1975
Inventory of California Natural Areas
Revision © 2009 Steven Louis Hartman