Above: The Santa Rosa reserve near Camp Pendleton is the largest remaining native California grassland. The landscape looks like much of southern California before modern settlement. Left: The study area is a vast tract of land separating Los Angeles from San Diego. Camp Pendleton is in purple.Photograph by Frank Kluber

Carl Steinitz thinks it just possible that the U.S. Marines will come to the rescue in southern California. The benefit-to-cost ratio of doing so might be more than five to one.

Steinitz, Wiley professor of landscape architecture and planning, likes to tackle complex land-use problems with complex politics attached to their solution, presenting himself and his students with "the most difficult, murky, ill-defined, shapeless projects" he can find.

Take, for example, the region surrounding Marine Corps Base Camp Pendleton in southern California. The study area is a 5,600-square-mile piece of precious, and still beautiful, real estate separating Los Angeles from San Diego. The base comprises 124,000 acres and is the largest unbuilt portion of land on the southern California coast. A million people live in the region;

PAUL COTE

forecasters predict a half million more will join them by 2010. All of the area's unbuilt private land is zoned or planned for development and is urbanizing with enormous rapidity. It is also one of the most biologically diverse regions in the continental United States, rich in species whose habitats there are menaced. The forces of conservation and development are in high conflict.

The Biodiversity Research Consortium, a federal interagency group whose mandate is to figure out how the United States should assess its ecosystem health, chose the region for a study of urbanization as a stressor on biodiversity. Steinitz was picked to lead a team from the consortium and Harvard, Utah State University, the

A computer-generated map of conflict between development and conservation interests. "It is an assessment," says Carl Steinitz, "of the extent and degree to which the development interests value unbuilt, developable land in the area, represented by redder colors, and the conservation interests seek to preserve land, represented by greener colors. Darker, browner colors show areas where interests are in great conflict, meaning both want the land a lot. The strategy of the proposed design is to go for the conservation/development conflict areas, and get there first with conservation, letting developers concentrate on the areas that they want but that aren't in conflict, and leaving the areas that they don't want alone because we don't have to take a great deal of action to conserve them de facto." CHAD ADAMS AND LOIS EBERHART

National Biological Service, the Forest Service, the Environmental Protection Agency, and the Nature Conservancy. (Funding for the two-year study came from the Strategic Environmental Research and Development Program, a joint program of the Departments of Defense and Energy and the Environmental Protection Agency.)

The researchers' 1996 report showed that if existing development plans are carried out, agriculturally productive soil will almost completely vanish except on military land; several important species, including some that are threatened and endangered, will have significantly smaller habitats; populations of the region's 375 vertebrate species will decline, and about 20 species, most of them birds, may become regionally extinct; vegetation will change due to the suppression of fire, while houses in fire-prone areas will suffer an increased risk of catastrophic fire; and flooding from storm runoff in the five major river basins will carry havoc downstream as land upstream is paved. The researchers and a group of Steinitz's graduate students designed, presented, and compared five alternative strategies for the development of the region. (The names of all of the analysts and their complete report may be found on the Graduate School of Design's website; see E-mail and Web Info.)

Last fall Steinitz gave his graduate students a further assignment, with funds to pursue it provided by the School of Design. Could they come up with a solution that might be better than any of the alternatives presented in the research report?

A photograph (top) of a site at the crossing of Warm Springs Creek and I-15 that is under intense development pressure. The first simulation (center) shows development as it is likely to occur if present trends persist: typical American urban sprawl. Commercial and industrial development is scattered along all major roads and in the creek's riparian corridor. The proposed design strategy (bottom) clusters commercial development at major intersections, guards against floods by maintaining the integrity of the stream corridor, and adds a golf course and recreational zone that will buffer the stream against the effects of adjacent residential development.TIMOTHY SLATTERY

According to Steinitz, "Yes, they could. The students' plan [also on the website], built on those in the earlier study, is the best, most reasonable, and potentially most feasible alternative, which accommodates a million new people in the area over the next 35 years, maintains biodiversity, and minimizes hydrological damage. It is close to economically viable." The students' plan puts a conservation strategy in place before development occurs. The acquisition of land targeted for conservation would cost $250 million; the cost savings to taxpayers of avoiding the flood-control measures that would be needed if that same land were developed would be $200 million. Thus, the plan doesn't quite pay for itself.

But here come the marines. They face the prospect that they may have to move the air base at Camp Pendleton--a matter of national importance--because of increasing floods caused by upstream development. The cost of the move: at least $2 billion. Steinitz and his students argue that implementation of the new plan, just published, might obviate the need to move the air base. Money saved could pay for the acquisition of conservation lands many times over. "There are serious questions about the ability of the civilian and military sectors to interact to help resolve these issues, but it's the only way to make the economics work that I can see," says Steinitz. "It would be a benefit ecologically, and for the citizens there, and for the military. It's a win, win, win circumstance."

~ Christopher Reed