The Guanacaste idea.

The stakes are high and time is short as scientists try to create a living, working, profitable ecosystem in what is being called the largest restoration project ever attempteed in the tropics.

ON A TORRID PLATEAU between a string of volcanoes and the Pacific Ocean, Julio Diaz kneels, brushes aside some leaves and grass, and spills water from a canteen. Instantly, dozens of minute brown seeds begin writhing, propelled by a corkscrewing motion of their beards. As Diaz stands, he explains that these seeds of "jaragua" grass are pushing themselves into the ground for protection against the parching tropical sun.

Jaragua is a popular pasture grass that has adapted perfectly to the seasonally dry climate here in Guanacaste Province. With a great deal of help from range fires, jaragua is crowding out the few remaining scraps of dry tropical forest in northwestern Costa Rica.

And that makes this aggressive grass public enemy No. 1, as far as Diaz, the fire-crew chief at the Guanacaste Conservation Area, is concerned.

Five centuries ago, a magnificent dense forest covered more than 200,000 square miles of Pacific coastal lowlands from Panama to Central Mexico. Today, after centuries of timber cutting, farming, and ranching, only about one one-thousandth of that area is still recognizable, and only a few hundred square miles are in preserves.

Not so well known as the rainforest, dry tropical forest is equally valuable--and far more endangered, according to Peter Raven, director of the Missouri Botanical Garden and an expert on tropical ecosystems. "The Mesoamerican tropical dry forest now exists in very tiny, scattered remnants of enormously altered forest," says Raven. "The dry forest is every bit as rich in local species, in endemic organisms, as tropical rainforests. In South America, dry forests are actually richer in reptiles than rainforests. They are very, very important."

Twenty years ago, as the world began focusing on the accelerating destruction of tropical rainforests, a group of Costa Rican scientists and conservationists were worrying about the surviving scraps of dry forest in Santa Rosa National Park (which later would form the nucleus of Guanacaste Conservation Area). The biggest problem was fires started by arson, accident, and ranchers who wanted to eradicate tree seedlings from pastures. Some of the fires blew a dozen miles, from the feet of the volcanoes all the way to the beach. In their wake, jaragua expanded its grip on the land.

Instead of giving up and moving on, these scientists decided to test a radical solution--a hybrid of biological and social techniques aimed at creating a living, working, profitable ecosystem.

The first step was to convince Costa Pica to set aside 423 square miles of land, stretching from the ocean to beyond the Continental Divide, as a reserve so large and varied that native species could migrate, survive, and evolve. Says Harvard entomologist E.O. Wilson, an authority on the relationship between size and species richness of nature preserves, "The concept [at Guanacaste] is very sound--to broaden the area as much as you can, and to go up and down in altitude as much as possible. This maximizes the number of habitats and the amount of biodiversity." In Guanacaste, for example, animals tend to migrate during the dry season away from the parched coast, to the more humid forests in mountains to the east, and a reserve designed to house these species must protect all their seasonal habitats.

Indeed, Guanacaste is a living encyclopedia of tropical habitat: dry forest, cloud forest, rainforest, reefs, rivers, and beaches. It has an estimated 325,000 plants and animals (an astonishing 3 to 6 percent of the world's total biodiversity). It has at least 700 tree species and one-third as many higher (vascular) plants as the United States and Canada, which are 17,000 times as large.

The planners did not want Guanacaste to be a national park in the traditional sense; instead, they were determined to integrate the reserve into the national social and economic fabric and make it a "working asset" for Costa Rican society. Yes, the conservation area would be a tourist destination, but it would also be a major employer and educator of local people, and the site of an intensive search for new seeds, drugs, and industrial chemicals. Yes, previous national parks in Costa Rica had hired a few ill-trained rangers, but the non-profit organization that operates Guanacaste Conservation Area on behalf of the Costa Rican government would stress the hiring and promotion of local people for managerial and scientific jobs.

And since the dry forest was on the verge of extinction itself, Guanacaste would become the largest ecological restoration initiative in the tropical world. In simple terms, here is how it would work:

On 200 square miles of grassland that had once been dry forest, Diaz and his crew would fight fires. Then winds and animals would import the seeds of native trees, vines, and shrubs. But the fire crews had to hurry. Otherwise, the seed-bearing plants would be burned to ashy stumps. Finally, after a century or so, the dry forest would return, with its armadillos and mountain lions, three species of monkeys, more than 300 species of trees, and dozens of thousands of invertebrates.

The bulk of the Conservation Area would be devoted, exclusively and in perpetuity, to non-destructive uses--tourism, science, and biodiversity prospecting (as the search for useful genes and chemicals among living organisms is known).

The audacious plan attracted attention. As Raven told me, "It's a very substantial block of real estate, so the effort to restore and manage it is very important on a worldwide scale. It's definitely the most interesting restoration in the tropics, and almost certainly the largest."

Much is at stake in Guanacaste. Time is growing short for conserving the genetic and ecological beauty and the useful products hidden in the various types of tropical forests. Globally, about 65,000 square miles--an area larger than Wisconsin--of this rich habitat is destroyed each year, and biologists are warning about a wave of extinctions to rival the one that exterminated the dinosaurs. The invention of effective conservation and restoration techniques has never been more urgent.

The Dry Forest

Although "dry forest" makes some people think of the midwestern U.S. oak savannas, which are stippled with large deciduous' trees, the intense seasonal rains in Guanacaste produce a closed canopy with hundreds of tree species, precious little grass (except for some bamboos), and great diversity.

Though it's often difficult to identify trees in an area with such diversity, the "naked Indian" (Bursera simaruba) stands out. Also called the "sunburned tourist," its bark is green, glossy, and able to carry out photosynthesis. As it ages, the bark turns reddish-brown and peels, evoking the memorable name.

The gigantic strangler figs (members of the genus Ficus) are almost as hard to miss. These parasites sprout high in the canopy, drop roots to the ground, surround the host, and kill it. Eventually, stranglers develop into forest giants, their layers of overlapping wood fused into an eerie, gray, arboreal version of a drip castle. The strangler's message? The fittest, not the nicest, survive.

One of the most valuable timber species is the deciduous pochote (Bombacopsis quintanum). Large, straight-grained, and soft-wooded, this tree's growth habit is reminiscent of a bur oak's. Pochote's bark is studded with half-inch spikes--a deterrent to climbing animals.

Other common trees include caoba (Swietenia macrophylla; we know it as mahogany); the yellow-flowered poro poro (Cochlospermun vitifolium), with a spare, branching structure and smooth, mouse-gray bark; the guanacaste (Enterolobium cyclocarpum), the province's namesake, a magnificent, broad-spreading, deciduous tree with a pod shaped like a monkey's ear; nispero (Manilkara chicle), the original source of chicle for chewing gum; and the evergreen guapinol (Hymeneaea courbaril), the source of fossil amber in the novel and movie Jurassic Park), with a brown-and-white bark and a pouch-shaped fruit.

In practically all of Guanacaste province's lowlands, however, these trees are isolated and failing to reproduce; ecologists call them the "living dead." The dry forest is so ravaged, in fact, that even the 423-square-mile conservation area has only two examples of how it looked before the Spanish colonization began. If you visit the 12-acre patch near headquarters, you realize that this forest has virtually-nothing in common with the beat-up pastures and scrubby trees along Guanacaste's roadsides. Instead, you'll notice the deep soughing sound as the wind stirs the coronas of huge trees, whose broad crowns and hefty trunks give an overall air of sylvan extravagance.

Fire

This postage-stamp of forest shows what was at stake in the mid-1980s, when conservationists in Guanacaste finally came to understand that intense fires were on the verge of destroying the dry forest's last relics. The problem was simple: After these fires burned everything to the ground, jaragua grass would rebound as dense, nine-foot-tall stands--surrounding the ashy skeletons of native trees.

While jaragua and fire are an ideal combination from a rancher's point of view, to conservationists they are a deadly one-two punch. Fires kill trees at the edges of pastures, creating sunny seedbeds for more grass and setting the stage for larger fires. Mario Boza, a founder of Costa Rica's national-park system, recalls that 10 years ago Santa Rosa National Park was "jaragua from horizon to horizon, 70 to 75 percent jaragua."

Thus fire control was top priority when the Guanacaste Conservation Area was dedicated in 1987. "Fire control got all the money, all the people it needed," says area director Sigifredo Marin. "The most important thing was to change the belief that fires in Guanacaste were impossible to prevent."

The Conservation Area bought two new four-wheel-drive trucks for its fire crew, and began using standard range-fire control techniques--clearing firebreaks (which now total 24 miles) and maintaining fire-access roads (now 54 miles). The burning enthusiasm to control fires caught on, and a province-wide "Committee Against Burning" was established. As Costa Ricans in general became more conservation-minded, the image of fire was transformed from the rancher's friend to the ecosystem's enemy.

By 1993, fires within the Conservation Area had diminished more than 90 percent, to about 5,200 acres per year. Nevertheless, crew members still report to work whenever the fire lookout on the volcano radios an alarm. And they still take pride in their key role in healing the landscape of their native province.

Many restorationists in the United States were confused by the obsession with fire control here. In the U.S. during the 1930s and '40s, deliberate fires were an essential step in the first successful ecological restorations on midwestern prairies. Yet Daniel Janzen, a University of Pennsylvania ecologist who lives half the year at Guanacaste's headquarters, points out that since Guanacaste has no lightning during the dry season, the native trees have simply not evolved the thick bark that protects oaks in the Midwest from fire.

Replanting

With the fire program in place, the reforestation strategy was to allow the strong, dry-season winds to blow in the seeds of native plants (23 of 321 species of local dry-forest trees use wind dispersal, according to Janzen). Since animals seldom venture far into pastures to disperse the seeds of other trees, the Conservation Area staff plants 4,000 to 9,000 trees per year in the most denuded areas, to establish seed sources throughout the 200 square miles under restoration.

To mimic natural groves, the trees are planted in groups of 12 to 15. Guiselle Brenes, chief of restoration programs, says a crew of eight spent a week planting 160 groups of seedlings on a 75-acre patch near headquarters. In 1993, her crews planted a total of 440 acres. Each tree is numbered so its survival can be monitored. (An experiment begun in 1989 found that the three-year survival of four native tree species varied from 3 to 55 percent.)

Since the goal is nature restoration, not silviculture, seeds are obtained locally, without selection for desirable traits. "We're trying to restore the forest as naturally as we can," says Brenes. "You want nature to select the strongest trees--these are all natives, so they all have the capacity to adapt to these conditions."

The Conservation Area also has a 17,290-acre experimental tree farm where silvicultural techniques are being developed and demonstrated to ranchers looking for crops to replace the moribund cattle industry. Janzen, who serves as an unpaid advisor to the project, stresses that this kind of tree planting is "growing woody crops," not restoration.

When I asked to check on the progress of the restoration, fire chief Diaz drove me along the fire roads in his smoky truck. For more than an hour we cruised through the area Costa Rican park founder Boza recalled as "jaragua from horizon to horizon" 10 years ago. Today, Jaragua is thriving only in the firebreaks, which are burned to the ground each year.

Janzen took me to one of those fire-breaks--a biological moat built in the late 1980s--and pointed matter-of-factly to a pure stand of golden, nine-foot jaragua waving in the wind. Downwind, after six years of fire protection, a thicket of 10- to 15-foot native trees dominated some scraggly pasture grass. Once the forest canopy closes--in 20 or 50 years--it will shade out this jaragua, and the danger of catastrophic fire will be almost nil.

"This used to be 50,000 hectares [125,000 acres] of 'beautiful' green grass," says Janzen, with a note of irony, as he waves toward the bulk of Santa Rosa National Park. "Today, the only place I can go to take a photo of grass is in the firebreaks."

To ensure that future generations would support the ecological restoration, the Guanacaste project is designed to produce so many benefits for Costa Rica that only a fool would want to destroy it. How is it doing on this score? For starters, it hires only Costa Ricans for its 87 positions, and most are natives of Guanacaste province. The organization also prefers to promote from within and give responsible, challenging jobs to people who otherwise would face extremely limited prospects.

But despite the progress, a declaration of victory at Guanacaste will always be premature, since the forest could quickly be converted into pasture if Costa Ricans lost interest in the conservation project. "It's very difficult to say it's a success," says director Marin. "It's not like closing a book--we'll always have more to do. But the number of hectares burned is down each year. Before, people said a national park was a luxury for a Third World country. We are not a luxury."

THE LESSONS OF GUANACASTE

In recent years, scientists and bureaucrats have been visiting Guanacaste Conservation Area from throughout Latin America, and even Sri Lanka and Japan, looking for lessons that can be exported to other parts of the tropical world. Recognizing that every conservation project must be tailored to its unique social, political, and ecological situation, what are the elements of the Guanacaste formula?

GET POLITICAL SUPPORT.

Guanacaste does not exist in a vacuum; it's the pilot project for conservation areas that will occupy abut 25 percent of Costa Rica. (Having so much land

under protection makes conservationists more agreeable to intensified agriculture and silviculture projects on other land.)

GET SOCIAL SUPPORT

Guanacaste hires most of its 87 employees locally, and has no foreigners on staff. It trains and promotes from within, paying more attention to demonstrated ability than university degree. It also operates a biological education program for all local grade-school students, to increase their appreciation for nature and gain their sympathy in the future.

GET IT TOGETHER.

Guanacaste Conservation Area encloses an entire ecosystem, from the ocean past the Continental Divide. It also provides unified administration to three national parks, reducing confusion in a country with many varieties of parks and reserves.

GET MONEY UP FRONT.

At the beginning, Guanacaste's planners raised endowment (mainly from donors in developed countries); that $16.3-million fund allows freedom of action and pays for first-class personnel, computers, vehicles, and buildings.

EARN MONEY.

Guanacaste is designed as a business venture that is so profitable to the local economy only a fool would threaten it. One potential source of income, the National Institute of Biodiversity (INBio), is cataloging, identifying, distributing, and exploiting Costa Rica's species. In 1991, Merck and Co., the drug company, paid INBio $1.135 million for about 1,100 insect, plant, and soil samples. Merck will pay INBio royalties if it discovers products in those samples, and INBio will devote half the royalties to Costa Rica's conservation areas (with the balance covering the operating costs of its national diversity inventory).

KNOW YOUR OPPONENT.

While "reforestation" usually implies planting trees, Guanacaste emphasizes fire control, creating a favorable "seed-bed," and letting nature take over. Ecologist Daniel Janzen says the restoration will inevitably succeed if the fire crews continue doing their jobs. "The biology is absolutely trivial--if you asked any biologist what would happen if you stopped the fires, this is what you would get."

USE IT OR LOSE IT.

Guanacaste disdains the traditional "hire-a-guard-and-put-up-a fence" mentality found in national parks worldwide. Says Director Sigifredo Marin, a veteran of the National Park Service, "Before, we weren't really managing the parks, we were protecting something we didn't know. Now, it's conservation, research, and putting this area to the service of the development of the country."

DAVOD TENENBAUM--a Madison, Wisconsin, environmental writer, recently spent two weeks in Costa Rica researching this article.