Selective logging–the practice of removing one or two trees and leaving the rest intact–is often considered a sustainable alternative to clear-cutting, in which a large swath of forest is cut down, leaving little behind except wood debris and a denuded landscape. 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 October 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, the scientists were able to detect openings in the forest canopy down to just one or two individual trees. 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.