Public Release: 

Amazon roads may lead to peril for rainforest

Michigan State University

EAST LANSING, Mich. - Brazil may call its plan to carve roads through the fragile Amazon rainforest "Advance Brazil," but a study published in this week's Science shows that the plan's long-term environmental impact could make it a leap backwards.

Using satellite data to paint detailed pictures of the impact of past development, MSU researcher Mark Cochrane and others have developed the first models of what proposed road construction would do to Brazil's rainforest.

In a policy forum in the Jan. 19 edition of Science entitled "The Future of the Brazilian Amazon," the research team uses history as a teacher to, for the first time, project the impact of "Avança Brasil" (Advance Brazil) - a program to fast-track infrastructure in the Amazon for economic development. Their findings: that the roads' most significant impact will be devastation of rainforest, and a clear path to more destructive forest fires, reduced wildlife resources and more release of greenhouses gases.

"We're basically talking about losing rainforest land the size of Rhode Island each year," Cochrane said. "We're trying to map out the implications to let them know what the consequences are. We feel it hasn't been looked at yet."

Cochrane, who is part of MSU's Basic Science and Remote Sensing Initiative, created satellite-based models with lead author William Laurance of the Smithsonian Tropical Research Institute, MSU doctoral candidate Christopher Barber, Scott Bergen of Oregon State University, Philip Fearnside of the National Institute for Amazonian Research Ecology Department and Patricia Delamônica, Sammya D'Angelo and Tito Fernandes of the Biological Dynamics of Forest Fragments Project in Brazil.

The rainforest, Cochrane explains, exists in a delicate balance. Logging and mining may not immediately level a segment of forest, but can weaken and thin a tree stand enough that, over time, is more susceptible to fire or other devastation.

"When you view these forests from a distance, they look OK, but when you stand in them, you can see they've been thinned, and that they've changed," he said. "You can see how they've been chewed up. It's like they have holes punched in them. These holes can make a rainforest dry out and be vulnerable to fire."

The group created two scenarios - optimistic and nonoptimistic. The optimistic scenario assumes that people will not venture more than about 30 miles from the new roadways. Cochrane, however, said that in the past 20 years, additional roads have been opened up for development more than 100 miles deep into the forest. Brazil calls the highways a path to economic advancement, but the scientists caution that the environmental losses could offset the economic gains.

The researchers also point out that, as past models show, development in these areas of Brazil is unchecked. The roads are the first - and perhaps only - line of defense.

"Unfortunately, there is little government control in the Amazonian frontier," Laurance said." Illegal logging and land-clearing are rampant. New roads that cut into the frontier almost always initiate a process of spontaneous colonization, logging, hunting and land speculation that is almost impossible to stop. The only way to control these processes is to control where the roads are located."

The article notes that already several domestic and international efforts are under way to protect the Amazon's environment, but the research models indicate such conservation efforts "will be overwhelmed by prevailing destructive trends."

Cochrane said his team is not blind to Brazil's need for economic development, but that it's imperative the country knows where the roads will take them.


The Avança Brasil project is currently being funded by the Brazilian Government and international private investors.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.