California's Oak Woodlands PDF Print E-mail
 
Photo
Photos by Tom Gaman


Photo


Photo

 

Tools and Links | Discussion

Management Forest Type Descriptions Forest Health

Climate Change and Carbon

General Resources

Discussion ^

Thanks to Guild Member Tom Gaman for his suggestions on this page.

California’s oak woodlands provide habitat for nearly half of the 632 terrestrial vertebrates found in the state (Tietje et al. 2005), but they are under threat from development and sudden oak death. Oak woodlands and oak forest cover 8.5 million and 4.5 million acres respectively and combined cover 12 percent of California (Gaman and Firman 2006). While oak forests are concentrated in the North Coast and North Interior regions, more than half of the oak woodlands are in the Sacramento and San Joaquin regions (Gaman and Firman 2006). The most common species in oak woodlands are blue, canyon, coast, and interior live oak, but black, Engelmann, Oregon white, tanbark, and valley oak are also represented (Gaman and Firman 2006). Native shrubs such as toyon (Heteromeles arbutifolia), redberry (Rhamnus crocea), manzanita (Artostaphylos spp.), poison oak (Toxicodendren diversiloba), cenaothus (Ceanothus spp.), and coffee berry (Rhamnus californica) all add to the habitat value of oak woodlands (Tietje et al. 2005). Oak woodlands are a fire adapted ecosystem which likely burned on the order of one to several times a century before fire suppression (Sugihara et al. 2006).

Acorns are a key resource for at least 45 different wildlife species such as deer, squirrels, turkeys, jays, quail, and even bear. Mast years, years when oaks produce large crops of acorns, are synchronized across individuals of the same species. As with most forest types, snags are an important habitat resource in oak woodlands for animals including bats, swallows, salamanders, and lizards (Tietje et al. 2005). Coarse woody material, particularly large logs are important in oak woodlands in part because they retain moisture in a relatively dry ecosystem (Tietje et al. 2005). Unfortunately, downed wood is lacking in most of California’s oak woodlands (Tietje et al. 2002).

Urbanization threatens 20 percent of California’s oak woodlands by 2040 (Gaman and Firman 2006). Development and other oak woodland losses could contribute 33 million tons of carbon that is currently sequestered to the atmosphere exacerbating global climate change (Gaman 2008). Oak woodlands are not covered by the California Forest Practices Act, but there are two other rules that effect their management: SB 1334 and the Oak Woodlands Conservation Act AB 242. Restoration of oak woodlands can help combat the development pressure. Restoration is more successful when it focuses on areas near existing oak resources, with high quality sites, and with good prospects for long-term sustainability (Bernhardt and Swiecki 2006). Prescribed fire has potential as tool for maintaining oak woodlands, but more research is need to guide site-specific prescriptions (Fry 2008).

References
Bernhardt, E. A., and T. J. Swiecki. 2006. Restoring Oak Woodlands in California: Theory and Practice. Phytosphere Research, Vacaville, CA.
            http://phytosphere.com/restoringoakwoodlands/oakrestoration.htm

Fry, D. L. 2008. Prescribed Fire Effects on Deciduous Oak Woodland Stand Structure, Northern Diablo Range, California. Rangeland Ecology & Management 61(3):294-301.
            http://www.bioone.org/doi/abs/10.2111/07-113.1

Gaman, T. 2008. Oaks 2040: Carbon Resources in California Oak Woodlands. California Oak Foundation, Oakland, CA.
            http://www.californiaoaks.org/ExtAssets/Oaks2040addendum.pdf
Gaman, T., and J. Firman. 2006. Oaks 2040: The Status and Future of Oaks in California. California Oak Foundation, Oakland, CA.
            http://www.californiaoaks.org/ExtAssets/Oaks2040%20Final.pdf

Sugihara, N. G., J. W. V. Wagtendonk, K. E. Shaffer, J. A. Fites-Kaufman, and A. E. Thode. 2006. Fire in California's Ecosystems. University of California Press, Berkeley, CA.
           
Tietje, W., K. Purcell, and S. Drill. 2005. Oak Woodlands as Wildlife Habitat. in D. D. M. Gregory A. Giusti, Richard B. Standiford, editor. A Planner's Guide for Oak Woodlands. University of California, Berkeley, CA.
           
Tietje, W. D., K. L. Waddell, J. K. Vreeland, and C. L. Bolsinger. 2002. Coarse Woody Debris in Oak Woodlands of California. Western Journal of Applied Forestry 17(3):139-146.
            http://www.treesearch.fs.fed.us/pubs/4853
 
< Prev
[ Back ]