South Coast

The South Coast bioregion contains the east–west-running Transverse Range and the north–south-oriented Peninsular Range. Except for the alpine zone, both ranges have a full complement of montane zones. Elevations extend from sea level to over 3,500 m (11,400 ft). In addition to montane vegetation types, low-elevation vegetation includes interior grassland, south coastal scrub, chaparral, foothill  woodland, and mixed evergreen forest. Despite the fact that Coastal California is greatly urbanized, including the San Francisco Bay Area, Los Angeles, San Diego, and their adjacent urban centers, these bioregions do still have large areas of wildland with relatively low human population densities (Keeley and Syphard 2006).

Prior to human entry into the bioregion, lightning ignitions were the only source of fire. It is hypothesized that the coastal regions burned when late late summer lightning-ignited fires were picked up and carried by the autumn foehn winds (Keeley and Fotheringham 2003). After Native Americans settled into the region by the middle Holocene, they used fire to control shrubland vegetation to promote the production of herbaceous species (Timbrook et al. 1984; Keeley 2002). Following Spanish settlement in the 1760’s, fire was used to promote livestock forage and allow for settlers and their herds to travel through the landscape. 

Though recent decades have experienced an increasing frequency of smaller fires (Mortiz 1997; Keeley et al. 1999), the probabilities of larger fires in the coastal region have not changed due to fire suppression (Moritz 1997). However, in the later half of the 20th Century, fire rotation intervals have shortened and average fire size decreased in all Southern Californian counties (Conard and Weise 1998; Keeley et al. 1999; Weise et al 2002). 

References

Conard, S.G., D.R. Weise. 1998. Management of fire regime, fuels, and fire effects in southern California chaparral: lesions from the past and thoughts for the future. Tall Timbers Ecology Conference Proceedings 20: 342-350.

Keeley, J.E. 2002. Native American impacts of fire regimes of the California coastal ranges. Journal of Biogeography 29: 303-320. 

Keeley, J.E., C.J. Fotheringham. 2003. Impact of past, present, and future fire regimes on North American mediterranean shrublands. Pages 281-262 in T.T. Veblen, W.L. Baker, G. Montenegro, and T.W. Swetnam, editors. Fire and climatic change in temperate ecosystems of the Western Americas. Springer, New York.

Keeley, J.E., C.J. Fotheringham, M. Morais. 1999. Reexamining fire suppression impacts on brushland fire regimes. Science 284: 1829-1832. 

Keeley, J.E., A.D. Syphard. South Coast Bioregion. Pages 350-390. In: J.W. Van Wagtendonk, N.G. Sugihara, S.L. Stephens, A.E. Thode, K.E. Shaffer, J.A. Fites-Kaufman, editors. Fire in California’s Ecosystems. University of California Press, Oakland, California, USA.

Mortiz, M.A. 1997. Analyzing extreme disturbance events: fire in the Los Padres National Forest. Ecological Applications 7: 1252-1262.

Timbrook, J., J.R. Johnson, D.D. Earle. 1982. Vegetation burning by the Chumash. Journal of California and Great Basin Anthropology 4: 163-186.

Weise, D.R., J.C. Regelbrugge, T.E. Paysen, S.G. Conard. 2002. Fire occurrent on southern California national forests - has it changed recently? Pages 389-391 in N.G. Sugihara, M.E. Morales, T.J. Morales, editors. Proceedings of the symposium: fire in California ecosystems: integrating ecology, prevention, and management. Miscellaneous Publication No. 1, Association for Fire Ecology, Sacramento, CA.