Up in Smoke

In Brazil, the Amazon rain forest extends across 1.3 million square miles—and yet patches of land measuring just 386 square miles might be the best hope for ensuring the survival of the vast ecosystem, one of the world's largest and most diverse.

The site is home to the Biological Dynamics of Forest Fragments Project (BDFFP), operated jointly by the Smithsonian Tropical Research Institute (STRI) and Brazil's National Institute for Amazonian Research. For nearly 30 years, scientists and students at BDFFP have been gathering crucial data on the environmental impact of farming, logging and human settlements. Now, however, the study area is threatened by those very same activities. "It would be tragic to see a site that's given us so much information be lost so easily," says William Laurance, a STRI biologist who has been working on the project for 12 years. Originally slated to run until 1999, the project is still flourishing.

At issue is the perennial conflict between natural conservation and economic development. The research site is located within the Agricultural District of the Manaus Free Trade Zone, which the Brazilian government established in 1967 to attract commerce to the region. The agency that manages the zone, SuperintendÍncia da Zona Franca de Manaus (SUFRAMA), recently announced plans for at least six colonization projects that would relocate 180 families in an area that encompasses the research site.

It's an especially bitter turn of events for the scientists, whose research plots have already been subjected to raids, equipment theft and burning by colonists for the much desired commodity, charcoal.

Laurance and his colleagues have focused their studies on what is known as "forest fragmentation." Rain forest clearing does not occur in one clean sweep; rather, it is a patchwork of encroachments that create oases of near pristine forest. The question is how large these forest fragments have to be in order to sustain their delicate ecosystems. Finding an answer could prove vital in planning development projects that would allow for human settlement without unnecessarily destroying swaths of forest.

The researchers cleared the surrounding areas to create patches ranging from 2.5 to 250 acres. By comparing data from each plot before and after it was isolated, scientists have found that the larger the fragment, the better. If it's too small, the entire ecosystem unravels: drying winds penetrate the interior, killing trees. Animals suffer too. In a recently completed study of bird extinction patterns, the researchers found that fragments less than 250 acres lose half of the bird species in the forest's interior within 15 years. That loss is too rapid for bird populations to recover.

Such findings argue against settling the area, environmental advocates say. Claude Gascon of Conservation International acknowledges that the Brazilian government is "within its mandate to use land for economic development" but believes it "should align [its] policies with what scientific results have shown." For its part, the Brazilian agency behind the settlement move, SUFRAMA, stresses that it conducted an environmental survey in 2004, and that it is "only the initial stage of a wide-ranging implementation process." SUFRAMA also contends that it "has striven to give its full support to the work of research institutions" in the area. Smithsonian's Laurance disagrees. He says the agency's proposed incursion into the research area ignores the findings of its own study.

The scientists are now enlisting the help of sympathetic agencies such as the Brazilian Institute of Environment and Renewable Natural Resources. Laurance emphasizes there is little to be gained by colonization, as the Amazon's low-quality soil makes for poor agriculture. "The social and economic benefits are paltry relative to the scientific and conservation benefits," he says.