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Oak Woodlands

Photo by S. Drill:  Coast Live Oak, Paramount Ranch, Santa Monica Mountains Recreation Area.    

Oak Woodlands are one of California's most iconic landscapes.  Oaks provide aesthetic, cultural, economic and environmental benefits.  California's first human inhabitants relied heavily on acorns as a food source.  Because of this iconic value, there are many policies and programs designed to protect oak woodlands as well as individual trees.  Most counties in California have or are developing oak woodland management plans, and many municipalities have laws that regulate when and how oaks can be pruned or removed.

For more information on oak woodlands conservation, please visit the UC ANR Oak Woodland Management site at http://ucanr.org/sites/oak_range/.

To learn more about LA County's Oak Tree Ordinance (applicable to unincorporated areas and many of the cities where LA County Fire provides forestry support), please visit http://www.fire.lacounty.gov/Forestry/EnvironmentalReview_OakTreeOrdiance.asp.

For more information about oak conservation in Ventura County, please visit http://www.ventura.org/RMA/planning/ceqa/bio.html.


Photo by S. Drill:  Oak woodland near Quail Lake, Antelope Valley, Calif.

Goldspotted Oak Borer
California's oak trees are facing another challenge to their survival.  The goldspotted oak borer (GSOB) was identified in California in 2006.  Since that time, more than 17,000 oaks have died from this pest.

The loss of oak trees, especially in the wild, brings many negative impacts:  loss of wildlife habitat, greater risk of erosion and catastrophic fire, invasion of noxious weeds, and safety risks related to falling trees or branches.

The borer attacks the trunks and branches of mature oaks.  While most pests attack trees that are stressed or weakened, the GSOB attacks large, healthy trees, including trees in yards.  Thus far, the damage has been contained to San Diego County.

Much work is being conducted in an effort to learn more about the GSOB.  With more knowledge, researchers hope to be able to stop the destruction of these magnificent trees.  At this time, all we can do is work together to slow the spread of the GSOB wtih the following steps:

  • Do not transport oak firewood into or out of campgrounds or parks.
  • Chip infested oak wood to one-inch pieces.
  • Cover stored oak firewood with six mm, UV-stabilized, durable plastic tarps in the spring.  Secure all the edges of the tarp to the ground to prevent beetles from escaping.
  • Season oak firewood.  Remove the bark and place the wood in direct sunlight.

For more information on the goldspotted oak borer, including upcoming workshops, please visit Pest and Diseases of Southern California Oaks.

Los Angeles Oak Woodland Habitat Conservation Strategic Alliance
The Alliance was created as a result of a UC-IHRMP oak management meeting held in 2007.  The group was formed by Rosi Dagit of the Resource Conservation District of the Santa Monica Mountains.  The group's goal is to provide LA County and cities with policy tools and an information base to resolve conflicts between land development and oak woodland conservation.  UC Cooperative Extension's role is to provide scientific information, including the current distributioin of oak species in the county and analyses of the efficiency, costs, benefits, consequences and constraints of the policy tools developed by the Alliance members.

Members include:  the LA County Fire Department, UC Cooperative Extension, USDA-Natural Resource Conservation Service, Resource Conservation Districts, International Society of Arboriculture, Newhall Land Company, the Building Industry Association, LA County Regional Planning, National Park Service, and a group of city and private arborists, planners and consultants.  The group is funded by LA County, which is coordinated by the offices of Supervisors Zev Yaroslavsky and Michael D. Antonovich.

Please check back for more details soon!

Sudden Oak Death
On March 10, 2004, the California Department of Food and Agriculture announced that the fungus which causes Sudden Oak Death (SOD), Phytophthora ramorum, was found at a nursery in Los Angeles County. Agricultural officials and the nursery owner responded rapidly to make sure that no infected plants were transported off the site after the infection was discovered. Sudden Oak Death has killed thousands of oak and tanoak trees in 12 counties in Northern Coastal California. At this time, it is considered unlikely that SOD will have a significant impact on oak woodlands in Southern California, due to our drier climatic conditions. University of California has taken a lead role in monitoring and developing responses to Sudden Oak Death. For more information on Sudden Oak Death, see the California Oak Mortality Task Force at

For the latest news on Sudden Oak Death in Los Angeles County, go the Los Angeles County Agricultural Commissioner's Office at http://acwm.co.la.ca.us/