Endangered Species Act Recovery Plan Set for Two Unique Bay Area Plants

“The city of Oakland has an opportunity to help recover one of its unique native species by stopping the careless and illegal vegetation removal that has resulted in severe declines of pallid manzanitas in the Oakland hills,” said Jeff Miller of the Center for Biological Diversity. “All known occurrences of pallid manzanita have been mapped and can be avoided during development and fire-management activities. Effective vegetation management and fire hazard reduction don’t require the destruction of unique, vanishing local plants.”

Nearly three-quarters of the pallid manzanita population have been lost since 2002. One-third of all remaining pallid manzanita plants occur in the backyards of homeowners, and many are targeted for removal by the city of Oakland and the East Bay Regional Park District’s wildfire-management plan. The Oakland hills population has been reduced by almost half due to bulldozing for development, destruction of plants and mismanagement by the city. Some of the causes of the losses include failure to survey for endangered plants, shoddy environmental review for development projects, careless vegetation removal, improperly managed goat grazing, herbicide use and failure to enforce management plans. The species is also threatened by shading by non-native and native vegetation and a virulent root fungus that is killing pallid manzanitas at two locations. Since 1998 volunteers with the Friends of Sausal Creek have worked to ensure the survival of two important stands of pallid manzanitas within the upper Sausal Creek watershed through brush clearing, monitoring and advocacy.

“These endemic Bay Area plants grow nowhere else, and it would be tragic to lose either of them through careless vegetation management,” said Miller. “The recovery plan is a road map for protecting and recovering their small populations to ensure that future generations have a chance to see pallid manzanita and Baker’s larkspur thriving in the wild.”

Background

Pallid manzanita (Arctostaphylos pallida), a fire-adapted shrub that lives in maritime chaparral vegetation in the East Bay hills, was listed as endangered in 1998. It is a plant of extremes: It can grow to heights in excess of 13 feet on thin, low-nutrient soils, but is highly shade intolerant and requires frequent summertime fog as well as fire for natural seed germination, but not frequent fires that deplete the soil seed bank. There are an estimated 1,353 mature pallid manzanita plants remaining, with the largest naturally occurring colony in Huckleberry Botanic Regional Preserve and adjacent private lands along Skyline Boulevard in Oakland, and satellite colonies in nearby Sibley Volcanic Regional Preserve and Redwood Regional Park. The other natural population is in Sobrante Ridge Ecological Preserve in Richmond. A smaller planted population occurs near the Tilden Park Botanical Garden.

The goals of the manzanita recovery plan are to minimize the spread of the non-native root fungus Phytophthora cinnamomi, treat manzanita stands infected with the fungus, remove or trim native and nonnative vegetation that shades pallid manzanita, expand existing manzanita stands, establish additional stands, and protect the manzanitas from destruction by development and wildfire fuel-reduction activities.

Baker’s larkspur (Delphinium bakeri), a flowering plant in the buttercup family, was known to grow in only three locations in southern Sonoma County and northern Marin County, on decomposed shale soils within moist coastal scrub. Former populations in Coleman Valley and near Salmon Creek in southern Sonoma County are now extinct. One very small population remains east of Tomales Bay in western Marin County, with only seven plants found in 2006. This last population is threatened by roadwork such as mowing for right-of-way maintenance, use of herbicides, over-collection and sheep grazing. Many larkspurs were accidentally mowed by a county road maintenance crew in 2002, and the species was nearly driven extinct in 2004 by road workers using heavy machinery to unclog a roadside drain.

The goals of the Baker’s larkspur recovery plan are to expand the existing population, establish additional self-sustaining populations throughout its former range, protect plants from incompatible uses such as road maintenance, and reduce foraging on existing plants by slugs, snails and gophers to the point that they do not affect the species at a population level. The Marin Municipal Water District, Fish and Wildlife Service and U.C. Botanical Garden brought Baker’s larkspur seeds into cultivation and are attempting to reintroduce the plant into the wild in suitable habitat near Soulajule Reservoir in West Marin.

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 900,000 members and online activists dedicated to the protection of endangered species and wild places.

Press Release: August 21, 2015
http://www.biologicaldiversity.org/news/press_releases/2015/bay-area-plants-08-21-2015.html

Center for Biological Diversity
http://www.biologicaldiversity.org/