A Family Legacy.

Following in his father Aldo's footsteps, Carl Leopold is planting trees in Costa Rica to help restore that country's tropical forests.

Two-thirds of a century have passed since conservationist and author Aldo Leopold bought "The Shack" in south-central Wisconsin, launching a decades-long family commitment to forest restoration. But though his son, Carl, is 81 years old, he can't stop planting trees.

Leopold launched the Tropical Forestry Initiative (TFI) in 1992 on 350 mountainous acres near Dominical, Costa Rica, as a hands-on demonstration that tropical forests can be restored. Just as important, TFI is a nursery that annually supplies thousands of seedlings--now more than 40 species worth--to local farmers and landowners. The seedlings help restore tropical forests, which provide homes for 90 percent of the earth's plant and animal species but which also have suffered heavily from logging and burning over the past half century.

"Forest restoration is a worldwide issue," Leopold says. But while there are volumes written on how to restore forests in temperate climates, we know so little about restoring forests in the tropics. And the factors involved are vastly more complex."

Leopold began traveling in Costa Rica during the late '8Os. There he learned that this once entirely forested country now imports more than $500 million per year in timber products. Indeed, barely 15 percent of its original forest cover remains. Yet one acre of tropical forest may contain hundreds of tree species, whereas an acre in temperate regions might contain a few dozen.

"I was in awe of the forests that were left, but I always felt like such a tourist, which, after all, I was," Leopold says. "Then a friend suggested that several of us pitch in and buy some land in Costa Rica to use as a base for our travels. At once the idea of beginning a project in rainforest restoration came to me, and everyone else was enthusiastic."

Enthusiastic, indeed. By its second year TFI had 10,000 sturdy young saplings. Soon TFI added consultations on erosion control, wetlands restoration, inter-planting cacao in the reforested understory, and establishing forested corridors for wildlife.

"One of the most important outgrowths of TFI is the Asociacion para la Protecion de los Recursos Naturales del Valle Guebo--the Community Forestry Association," Leopold says. "It's a local collective, formed in 1998, of 25 families working to conserve their forest resources. In fact, the members have agreed to plant 50 seedlings for every tree they cut."

Every July student interns come to TFI to research everything from the improving water quality of local streams to using ants as indicator species for forest regeneration. They help biologist David Knowles map changes in vegetation complexity, or they participate in ecologist Dick Andrus' twice-yearly bird census.

"Bird species at TFI have doubled as the complexity of our forest increases," says Leopold. "It's the most obvious sign of our success, so far, in regaining forest complexity. Plus we've got a diversity of trees growing with canopies at different heights, exploiting different root zones, and fruiting at different seasons.

Leopold is an eminent plant physiologist who discovered the essential metabolic process that allows seemingly inanimate seeds to quicken and spring to life with revivifying moisture. But he has been active in environmental issues all his life, and forest restoration is in his blood. When he was a teenager, "The Shack" was the center of his world.

"I'm not sure how he did it, but our dad inspired us five kids completely," Leopold says. "We all wanted to bring that old, worn out farm back to beauty."

Mary Woodsen from Willseyville, New York, writes about natural history and environmental issues.