Princeton Weekly Bulletin, April 6, 1998

EEB professor studies cost of conservation

By JoAnn Gutin

On a mellow evening in September 1995, Andrew Dobson, associate professor of ecology and evolutionary biology, was sitting on a beach in Sulawesi, Indonesia, with a couple of colleagues, sipping a drink and thinking about economics.

In one way, the subject marked something of a change for Dobson: an ecologist, his specialties are the population dynamics of birds and mammals, the epidemiology of infectious diseases, theoretical ecology, and wildlife conservation. In another way, though, finance is not as much of a stretch as it sounds.

Dobson has spent a lot of time worrying about the embattled statute known as the Endangered Species Act, a document that has seemed to pit economics and ecology against one another since it was passed in 1973. He had come to believe that the Endangered Species Act had become a political football partly because no one knew how much money it would actually cost to protect the thousand or so species listed as endangered in the United States.

As Dobson recalls that September conversation, his colleague and former graduate student David Wilcove *86, now of the Environmental Defense Fund, asked, "If I could get a list of all the endangered species in the U.S., county by county, could you come up with a mathematical way to figure out how much land you'd need to save one population of each?"

And Dobson replied, "Sure."

The conversation resulted in a controversial paper that appeared in Science last winter. It also launched Dobson, Wilcove and graduate students W. Mark Roberts and Jon-Paul Rodriguez into researching the economics of conservation in a way that continues to generate provocative results.

The work is particularly significant now, as the Senate and House struggle to redefine the Endangered Species Act, which is up for renewal. The legislation has been trapped in a bureaucratic logjam for several years, and Dobson believes his work has helped move the debate forward. "Both sides have something new to argue about," he says.

Four hot spots

Dobson, Roberts and Rodriguez designed a computer algorithm that would search a database of counties containing endangered species, picking first the county with the most endangered species, then the county with the most species not found in the first, and so on, until every endangered species was accounted for.

Within six months, the group had produced a series of maps: one each for endangered plants, mammals, birds, arthropods and reptiles. The maps revealed that endangered species cluster in four areas they call "hot spots": Hawaii, southern California, Florida and southern Appalachia.

They found that if habitat in 214 counties -- a total of 500,000 square miles -- were protected, at least one population of each of the 1000 species currently on the federal endangered list could be saved. "You probably only need to set aside five to eight percent of the total U.S. landmass to save one population of everything currently listed as endangered," Dobson notes.

That observation produced the controversy. "There were people whose response was 'Oh, good; then we can develop 95 percent of the country,'" Dobson says. "Other groups protested that the goal of protecting one population of an organism was too modest and that more species were endangered than were listed. But what we really wanted to get across was that if you're worried about the Endangered Species Act, it's not a huge footprint that will stop development in the U.S."

Particularly in the northern and western parts of the country, Dobson points out, existing national parks and wilderness areas shelter fairly healthy populations of threatened and endangered species. "The best -- and cheapest -- way to save endangered species is to let Nature do the work for you and focus on ways of keeping functional ecosystems intact. You can do very constructive things by concentrating on a few small areas."

Pleasant for people as well

Recently, Dobson and his colleagues have been looking at U.S. real estate prices to learn if a relationship exists between the economic value of property to humans and its value to endangered species. The answer is yes: the most expensive land in the country is in southern California, Florida and Hawaii -- three of the four hot spots identified by the first set of maps. "Endangered species habitats tend to be pleasant places for people, as well as animals, to live," Dobson observes.

This latest work is designed to answer a political question: How can we get the biggest conservation bang for our real estate buck? Where and how should the government be protecting habitat?

The results are still preliminary, but Dobson thinks some messages are clear. Instead of purchasing expensive land outright, for instance, the government could get good results by fine- tuning the tax code.

"We ought to reward landowners in hot spot areas for preserving habitat and not subdividing -- by reducing estate taxes, for instance," he says. Tax dollars could then be spent acquiring less expensive land, providing wildlife corridors and buffer zones for endangered animals in more isolated parts of the country where real estate is cheaper. He is particularly enthusiastic about the so-called Wildlands Projects that aims to link the large parks that run -- "like a string of pearls," he says -- down the Rockies.

Ecology of money

Dobson hopes that the new focus on the economics of conservation may inspire fresh ways of looking at old problems.

"Ecologists have been branded as gloom and doom merchants for the past 25 years; it's fairly obvious that the strategy hasn't worked," he says. "We need to get out the message that ecology and environmental management can create jobs, can be good for the economy."

And he's figured out how to explain his new role as a sometime financial analyst. "I always tell people that economics is just the ecology of money."