Rainforest in Transition: Is the Amazon Transforming before Our Eyes?
The Amazon rainforest is in flux, thanks to agricultural expansion and climate change. In other words, humans have "become important agents of disturbance in the Amazon Basin," as an international consortium of scientists wrote in a review of the state of the science on the world's largest rainforest published in Nature on January 19. ( Scientific American is part of Nature Publishing Group.) The dry season is growing longer in areas where humans have been clearing the trees--as has water discharge from Amazon River tributaries in those regions. Multiyear and more frequent severe droughts, like those in 2005 and 2010, are killing trees that humans don't cut down as well as increasing the risks of more common fires (both man-made and otherwise). [More]