Santa Clara Valley Chapter

Plant Communities

Coastal Sage Scrub Serves As Planning Example

From The Blazing Star, Sept.-Oct. 1993

This April the coastal sage scrub community of southern California and the imperiled California gnatcatcher made headlines in separate actions that promise to redefine how the United States meets the challenge of conserving biotic diversity.

The California gnatcatcher, a diminutive gray bird weighing a mere six grams, and its southern California habitat, first attracted public attention a little more than two years ago when its presence on private properties and a citizen's petition to protect the species threatened to stop land development. In response, California Governor Pete Wilson convened a Scientific Review Panel to produce a conservation plan for coastal sage scrub habitat and the species it supports. After months of study, including the collection and review of more than 400 documents, analysis of mapped data on vegetation types and species occurrences, and conferences with environmentalists, biological consultants, and landowners, panel members have concluded that the existing technical information is insufficient to allow the design of a scientifically credible and legally defensible reserve system and management scheme for the threatened ecosystem.

Qualities of the coastal sage scrub itself limit the information available for conservation planning for that ecosystem. First, because most coastal sage scrub occurs on private property, access to the ecosystem has been limited. Second, the habitat itself has no intrinsic economic value outside of its development potential; thus, in contrast to resource-valuable ecosystems such as old- growth Douglas fir forest, the ecology and physiology of coastal sage scrub remains poorly understood.

However, the press of commercial and residential development in the coastal sage scrub makes immediate conservation prescriptions mandatory. At a press conference and briefing in La Mesa, California, Scientific Review Panel chairman and Center for Conservation Biology director Dennis Murphy introduced a plan that has met with approval from both environmentalists and developers, two groups that historically have found little of this issue upon which to agree.

During a period not to exceed five years, government agencies and members of the private sector will cooperate to fill the data gap by funding and carrying out a rigorous research and monitoring agenda that will focus on gathering demographic information on several species of special concern (the California gnatcatcher, the cactus wren, and the orange-throated whiptail lizard), completing GIS-based vegetation maps of the several million-acre planning area, and developing an explicit habitat restoration and enhancement policy. During this data acquisition period, development will be permitted to occur in no more than five percent of the remaining coastal sage scrub habitat. Mitigation will be required of any development projects such that there is no net loss of habitat quality, and projects will be designed such that they do not foreclose future conservation planning options (for example, by significantly diminishing large continuous habitat patches or by severing open space landscape linkages).

Secretary of the Interior Bruce Babbitt has embraced these prescriptions, and has pointed to this initial Natural Communities Conservation Planning program as a model process by which endangered species "train-wrecks" (such as the northern spotted owl fiasco) can be avoided. Further, Babbitt has listed the California gnatcatcher as a threatened species, thus institutionalizing the southern California conservation effort as the scientific and policy framework for conservation of and recovery planning for this species.

Many observers believe that the coastal sage scrub program, with which the Center for Conservation Biology has been so intimately involved, promises to replace the traditional emergency single-species applications of the Endangered Species Act with more proactive efforts to address biodiversity at the ecosystem level -- an ultimately much more effective approach to long-term conservation.

(Taken with permission from the Center for Conservation Biology Update, summer 1993, Vol. 7, No. 1.)