SEVERAL loud hoots silence the 5th grade students from Quebrada Grande, a small town in northwest Costa Rica's Guanacaste Province. The children are gathered in a knot in the dry tropical forest of Santa Rosa National Park, trying to locate the source of the sounds. ``Tienen miedo?'' (are you afraid?) biologist Gerardo Barboza asks. He is answered by murmurs of dissent, as his scanning eyes quickly locate a pair of owls high in a nearby tree.
Their hooting, Mr. Barboza explains, is an expression of displeasure at this intrusion on their daytime slumber. Then he quietly launches into an explanation of the owls' habits and vital role in the forest ecosystem.
The lesson has a serious message, says Barboza: These children will one day be decisionmakers. It is essential for them to learn that their well-being and that of their country is tied to the park's continuing as a source of environmental, economic, and intellectual wealth.
The Guanacaste National Park has become an unofficial prototype for Costa Rica's six other ``megapark'' projects, in part because it is integrating nearby residents into the park's future. It is also a model of protected zone planning and how to raise money for such efforts.
For 20 years, University of Pennsylvania biologist Daniel Janzen has studied Guanacaste Province's tropical dry forest with its distinct life forms and seasonal patterns. Dry forests, often attractive targets for residential areas and agriculture, are more severely threatened worldwide than their better-known tropical cousins, the rain forests.
Mr. Janzen works six months of each year in a small, tin-roofed cabin inside Santa Rosa. The cabin's interior is crisscrossed by clotheslines from which hang numerous plastic bags containing live forest insects. In 1984, he won the Crafoord Prize, environmental biology's most prestigious award, for his studies.
In addition to scientific and economic reasons, he says, it is necessary to protect biological diversity in places like Guanacaste ``for the intellectual development of the society....''
``Humans are complicated animals. In order for the human brain to function it needs lots of inputs - slicing the complexity of nature out of our inputs is like losing one of your senses.''
Lack of such inputs is a barrier to human fulfillment in many areas of the tropics where forests have been replaced by farms, says Janzen. It affects prospects for success in all areas of life, he argues, because ``a piece of what it means to be human, of our repertoire of mental stimulation, dies when diversity dies.''
The practical result of this philosophy is a park that is run primarily by the park's nearest neighbors and for their benefit. The administrative staff of 35, soon to double, includes teachers, caretakers, fire prevention crews, researchers, and rangers. All are Costa Ricans, and most come from the immediate area.
Educational programs are aimed at all visitors - foreign ``ecotourists'' are one targeted group - but especially local schoolchildren. Janzen says the programs are ``serious biology'' teaching ecological interdependence.
The project is expected to yield economic benefits as well. Janzen estimates that use of the park for research, education, and tourism will generate 4.7 times as much cash as its previous use for agriculture and ranching.
The notion of pervasive local involvement in the environmental program grew out of a 1985 challenge to Costa Rica's parks program. Several thousand gold miners invaded Corcovado National Park in the southwest. World banana prices had fallen and area plantations were closing. The region had a history of gold mining, but until then the boundaries of the 125-square-mile reserve had been respected by all but a few miners.
With no jobs and gold deposits outside the park already claimed, local residents had nowhere else to turn. But large-scale mining in the park was illegal and posed a threat of chemical pollution and sedimentation in park rivers.
The crisis passed with the help of peaceful persuasion and promises of compensation for some longtime residents, combined with judicial backing to evict recalcitrant miners. But economic conditions in the region have not yet improved to the point where similar problems are out of the question.
``We learned ... that we cannot just set aside a park and expect it to remain sacred,'' says Rodrigo Gamez, special adviser on natural resources to Costa Rica's President Oscar Arias. ``The social and economic problems of an area are as important to conservation as the environmental ones.''
Scientists and officials also had to understand the area's complex ecology to know where park boundaries should be set and obtain all the land inside those boundaries they didn't already own - with no money to start.
Today the 780-square-kilometer project has established borders and owns almost all the land within them; it will be officially opened sometime this year. It contains one of the few remaining pieces of the dry tropical forest that once stretched along the Pacific Coast from Central Mexico to Panama.
Janzen's observations of the interactions among Guanacaste's plants and animals have been crucial in determining just how big the park should be.
For example, he tracked a species of moth that disappears from Santa Rosa for part of each year - it moves to a rain forest on the slopes of a nearby volcano. The moths are part of the food chain in Santa Rosa, but their rain forest refuge had not been considered for inclusion in the Guanacaste project until Janzen realized it was needed to help sustain the web of life in the new park.
The area has since been designated part of the project, and the land bought and protected from development.
Other researchers track everything from the role of the spiny pocket mouse, the new park's most common mammal, to the habits of the numerous animals that store, or eat and then defecate or regurgitate the seeds of various trees, thus propagating the dry forest.
The project's goal, Janzen says, is to regenerate the original, closed-canopy dry forest in 50 to 100 years. He wrote in a recent report that if the project is successful, ``It will be the first example anywhere in the tropics where a small and endangered habitat was given back a large area to reinvade, and thereby get its population densities back to a more resilient level.''
Janzen also played a key role in raising money to buy land for the park. His talks around the United States were accompanied by a blitz of grant proposals to private foundations. President Arias also helped. In Sweden in 1987 to accept the Nobel Peace Prize, Mr. Arias explained Costa Rica's environmental program to an already-interested Swedish public.
The result was roughly $4 million in donations. The money came from American foundations, from a Swedish group that collected funds from individuals, and from the Washington-based Nature Conservancy, which set up a special fund for tax-deductible donations. In addition a US landowner donated 12,000 hectares that were inside the new park's borders.
Tropical biologist Thomas Lovejoy, the Smithsonian Institution's assistant secretary for external affairs, says Costa Rican officials ``have done a remarkably fine job'' in attracting outside support for their program.
``It hasn't been luck,'' says Mr. Lovejoy. ``They really want that park system, and they want to endow it and give it security.''
Asked if Guanacaste's experience can be duplicated in other tropical countries that don't have Costa Rica's relative advantages, Janzen says: ``You don't try to export it. You do it well at home and let other people come and look over the back fence.''
Second of two articles: The first ran on Jan. 4.