Conserving Oak Woodlands
Oak trees are a familiar presence in Monterey County, visible and cherished emblems of California’s natural world. Less visible is the critical role oaks play in maintaining the health of our region’s diverse ecosystems. Beneath the iconic grandeur and visual appeal of their spreading branches, the oak trees of the central coast are vital to the rich mosaic of plants, animals, lands and waters that comprise our extraordinary region.
California’s oak woodlands—densely wooded areas where the dominant trees are oaks—support an astonishing array of wildlife. For example, in Monterey County more than 1,600 plant and animals species live in and among oaks. This includes more than 50 species of mammals, 200 species of birds, 29 species of reptiles and amphibians, 260 species of bees and butterflies and 600 vascular plants. Monterey County has over half a million acres of oak woodlands, or more than 22% of the County’s total acreage. Our three most common species are the coast live oak (Quercus agrifolia), blue oak (Q. douglasii), and valley oak (Q. lobata). Coast live oaks are evergreens that grow primarily in coastal forests, but can also range inland. Blue and valley oaks, both of which are deciduous, thrive in the warmer, dryer interior foothills. Tanoaks (L. densiflorus), though not a true oak, are considered a relative and occupy cool, shady watersheds such as found in Big Sur. Under the right conditions oaks live two or three centuries; a few make it more than six hundred years.
A typical oak tree will produce tens of thousands of acorns and seedlings to be eaten by birds, mammals and insects. Yet the benefits of oaks go far beyond being a source of food. Oak canopies increase the water-holding capacity of soil by providing shade and wind protection. Many oaks are covered with lace lichen which catches nitrogen from coastal breezes. Rains rinse this nitrogen into the soil, increasing its fertility. Oak woodlands reduce erosion and sediment flowing into streams. They also play an important role in sequestering carbon from the atmosphere, reducing the buildup of toxic greenhouse gases.
Today, Monterey County’s oak woodlands are facing serious challenges. Removal for development, habitat fragmentation, poor regeneration and disease, notably Sudden Oak Death (SOD), all threaten the long-term health and survival of these vital trees. First detected in 1995, SOD is a fungus-like pathogen that continues to spread, killing millions of California’s oaks and other trees. It has caused extensive mortality in coast live oaks and tanoaks in Monterey County. Plant pathologists at UC Davis are currently investigating ways to control SOD, an effort that took on new urgency when the 2008 wildfires tore through Big Sur, where Sudden Oak Death has left large numbers of dead tanoaks.
In recognition of the value of oak woodlands and the threats they face, the State of California passed the Oak Woodlands Conservation Act in 2001. The Act established a bond fund and mandated that the State’s Wildlife Conservation Board (WCB) award grants to help local jurisdictions and landowners protect and enhance their oak woodlands resources. For local jurisdictions to access these funds they must have an Oak Woodlands Management Plan in place. With about fifty percent of Monterey County’s oak woodlands on private ranchland, having a source of grant funding to collaborate with private landowners on oak woodland stewardship and restoration projects is critical.
In September 2009 the Monterey County Board of Supervisors unanimously adopted a set of Voluntary Oak Woodlands Stewardship Guidelines
that will help local landowners protect and enhance Monterey County’s ecologically and economically valuable oak woodland resources. These adopted Guidelines will serve as the County’s Oak Woodlands Management Plan for the purposes of the WCB’s Oak Woodlands Conservation Program. Monterey County is now among the counties eligible for oak woodlands conversation funds.
The Big Sur Land Trust (BSLT), The Nature Conservancy, California Rangeland Trust, Elkhorn Slough Foundation, Ag Land Trust and others all strongly supported this action. BSLT is committed to working with Monterey County, private landowners, and other conservation interests to collaborate on projects to help protect the future of our oak woodlands.
For more information on California oaks, visit the Web sites of the California Oak Foundation and the WCB’s California Oak Woodlands Conservation Program.
For landowners who want to know what they can do to conserve their oaks, read “Living Among the Oaks. A Management Guide for Landowners.” Copies may be obtained from the University of California Cooperative Extension, Natural Resources Program, 163 Mulford Hall, Berkeley, CA 94720, or by calling (510) 643-5428.
An excellent resource is Oaks of California by Bruce M. Pavlik, Pamela C. Muick, Sharon G. Johnson and Marjorie Ropper, Cachuma Press, revised 1993.
Additional information on Sudden Oak Death can be found at http://www.suddenoakdeath.org/
