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Endless river. Rio Ucayali, a tributary of the Amazon in eastern Peru. (© 1998 Fred Powledge.)
Endless forest? The Amazonian forest frontier. (© 1998 Fred Powledge.)
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Carlos A. PeresSaving Amazonia |
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 Most people, when they think at all about “biodiversity,” probably think of Amazonia. This huge basin extends across 6 million square kilometers (2.3 million square miles) in seven South American countries. The celebrated river at its heart, the Amazon, collects the waters of more than 500 tributaries to drain some 40 percent of the continent. Because Amazonia is the global center of species richness (and relatively few examples of the human species), scientists like Carlos Peres have long been drawn to it. Peres is a Brazilian, born in Belém, where the Amazon joins the Atlantic Ocean. In recent years, the young ecologist has divided his academic life between the University of São Paulo and the environmental sciences school at the University of East Anglia in Norwich, U.K. But his research time is spent in Brazil — either in isolated sections of his native Amazonia or in the nation’s environmentally threatened coastal Atlantic forest. In both places, Peres’s work is a race against the clock. In the Amazon, more than in most places, biodiversity is vanishing at an alarming rate. Extinctions are occurring at a far greater speed than the normal “background” rate among species all along the ecological scale. Species of flora and fauna are disappearing largely because of human efforts: Traditional and sustainable methods of slash-and-burn agriculture (in which farmers clear land for crops, but also set it aside in fallow periods) have given way to a destructive form of land-clearing that depletes soil nutrients and replaces native species. Population pressures, often created by national subsidies and international lending policies, put more people into the forest, all of them having to earn their livings. More recently, forest fires have engulfed enormous regions of Amazonia. A mixture of forests. Carlos Peres’s work has given him an appreciation for the tremendous variety within the Amazonian forest. It is not just “rain forest,” but a mixture of forests with their own ecological structures that are based on their proximity to rivers. Some are inundated frequently, some flood only periodically, and others, called the terra firme, are unflooded. These last forests, Peres finds, are the most fragile, for they do not collect the bounty of flood-borne nutrients that elsewhere support large communities of mammal, bird, floral, and insect life. Peres’s main
headquarters in the Amazon is a field station at the Kayapó Indian village
of A'Ukrê. The Biodiversity Leadership Award helps to support the station,
along with several students from the universities of São Paulo and East
Anglia who work with the ecologist. It also helps defray the high costs
of transportation to the research site (in a two-seat airplane known
in the Amazon as a “goldminer”). Amazonia’s
fires. Recently,
Peres has evaluated the ecological and socioeconomic consequences of
“understory fires” — blazes in Amazonian forests once thought to
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be
practically immune to fire. In a report on this project, Peres writes:
“This study hopes to shed light on the mechanisms of biodiversity erosion
brought on by a combination of climatic and anthropogenic factors, which
may ultimately convert vast areas of evergreen forests into scrub woodland
and wooded savannas.”