Common ground for farmers and forests: alarmed by signs of extensive deforestation over the past decades, groups in Costa Rica are developing programs that combine ecological awareness and sustainable agriculture.

• Author: Wyels, Joyce Gregory

With more than 25 percent of its land protected in national parks and private reserves, Costa Rica enjoys an enviable reputation as an ecological paradise. Green-hued travel posters tout cone-shaped volcanoes blanketed by forests, home to a variety of flora and fauna all out of proportion to the diminutive size of this Central American nation. Rare toucans, resplendent quetzals, and scarlet macaws delight bird watchers, while adventure-travel enthusiasts wax lyrical about kayaking mangrove swamps, hiking verdant rain-forest trails, and rafting white-water rivers fringed with tropical foliage. Costa Rica's forests have even spawned a new sport: the ingenious canopy tour, in which participants don rappeling gear to zip through the treetops on cables attached to elevated platforms. From this vantage point, the travel posters have it right: broad vistas of undulating green spread toward the horizon, underscoring the tourism slogan, "All Natural Ingredients."

But a look at the landscape from an even loftier perspective suggests trouble in paradise. NASA (U.S. National Aeronautics and Space Administration) has compiled nearly thirty years' worth of photographs taken from space, which document the tracts of land covered in forest and the growing settlements, farms, and pasturage that continually chew at their edges. In 1993, student interns from EARTH University (Escuela de Agricultura de la Region del Tropico Humedo), with the support of NASA scientists, began interpreting the images. Last summer the results were released in Costa Rica desde el espacio (Costa Rica from Space), a compendium of 125 photographs published in book form with bilingual text by NASA and EARTH, with the financial support of UNESCO (United Nations Educational, Scientific, and Cultural Organization) and Banco San Jose.

The images, which include aerial and field shots as well as photographs from space, cast doubt on Costa Rica's green image. Whereas forest once covered 99 percent of the country, by 1983 it was down to 17 percent. The photographs show traces of fire along both coasts, and great swaths of pastureland replacing old-growth trees. Forests that once spread from the slopes of the Turrialba Volcano in the Cordillera Central to the flatlands of Tortuguero on the east coast have disappeared.

NASA astronauts, including Costa Rica's own Franklin Chang-Diaz, presented the book at press conferences and other public gatherings last summer. Newspaper editorials warned of dire consequences if the trend continued, one going so far as to predict that if San Jose and the surrounding Central Valley are transformed into a megalopolis, "within twenty-five years we would go from the `Switzerland of Central America' to the `Calcutta of the Caribbean'."

The loss of forest lands could decimate the carefully nurtured tourism industry, which has surpassed coffee and bananas as Costa Rica's number-one income earner. But reasons for concern go far beyond the loss of tourism revenue. Forest environments prove their worth in more ways than maintaining habitat for ecotourists or even for the wildlife that dwindles as forests become fragmented.

On a global level, tropical rain forests absorb excess atmospheric carbon, thereby reducing global warming. Locally, even the simple act of providing shade helps to regulate temperatures and safeguard organisms that affect plant and animal life all along the food chain. Moreover, trees and their root systems anchor the soil, keeping erosion in check.

One compelling reason for preserving the rain forest stems from our ignorance about the extent of its resources. In Costa Rica, where 0.035 percent of the earth's surface supports 5 percent of the world's biodiversity, the next medical breakthrough or nutritional supplement may be awaiting discovery among the endemic plants and organisms of a little-understood ecosystem.

Some of the most serious damage comes from commercial logging and roads cut into the forest. The heavy...