Every year, growing swaths of the Amazon rainforest are degraded by logging, fragmentation, and human-sparked fires. New research using airplane-based laser scanning of trees shows that degraded forests are hotter, drier, and more flammable than nearby “healthy” intact forests. But in periods of drought, intact forests also run out of water and start behaving like degraded ones, researchers reported recently in JGR Biogeosciences. Tropical forests benefit the planet by absorbing carbon dioxide from the atmosphere and generating water vapor to help spur cloud formation. This cycling of water from the Amazon rainforest back into the sky is sometimes called a “flying river,” as the water vapor travels to other parts of South America and eventually falls as rain. Researchers studied the shapes of different forest canopies to investigate how these functions shift in degraded areas. They used lidar, an airborne laser scanning system, to measure the structures of intact and degraded forests in the northern and central Brazilian regions of Belterra, Paragominas, Feliz Natal, and Tanguro, as well as in Paracou, French Guiana. Location of the five study regions within the Amazon biome, as well as land-type classification as of 2013. Study regions are donated with white diamonds. “SLB” denotes additional sites belonging to the Sustainable Landscapes Brazil land management program, which were also used to create the study’s computer model. Courtesy of Longo et al. (2020). To scan trees with lidar, researchers beam millions of light pulses from an airplane-based device into the forest. They measure the time it…This article was originally published on Mongabay Läs mer