But a new satellite survey of the Amazon Basin in Brazil reveals that every year unregulated selective logging of mahogany and other hardwoods destroys an area of pristine rainforest big enough to cover the state of Connecticut. The survey, published in the Oct. 21 issue of the journal Science, was made possible because of a new, ultra-high-resolution satellite- imaging technique developed by scientists affiliated with the Carnegie Institution and Stanford University.
"With this new technology, we are able to detect openings in the forest canopy down to just one or two individual trees," says Carnegie scientist Gregory Asner, lead author of the Science study and assistant professor, by courtesy, in the Stanford University Department of Geological and Environmental Sciences. "People have been monitoring large-scale deforestation in the Amazon with satellites for more than two decades, but selective logging has been mostly invisible until now."
Alarming results
The Amazon Basin contains the largest contiguous rainforest on Earth--a vast region nearly as big the continental United States that includes portions of Brazil and seven other South American countries.
Conventional satellite surveys reveal that, in an average year, an estimated 5,800 square miles of Amazon forest (roughly the size of Connecticut) are burned or clear-cut to make way for cattle ranching, farming and other development. But when selective logging is factored in, that figure increases two-fold, Asner and his co-workers found. "This was totally surprising to us and alarming to our colleagues, especially those interested in conservation, climate change and the ability of governments like Br
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Contact: Mark Shwartz
mshwartz@stanford.edu
650-723-9296
Stanford University
20-Oct-2005