ScienceDaily: Tropical forests hold more living biomass than any other terrestrial ecosystem. A new report in the journal Nature by Lewis et al. shows that not only do trees in intact African tropical forests hold a lot of carbon, they hold more carbon now than they did 40 years ago–a hopeful sign that tropical forests could help to mitigate global warming. In a companion article, Helene Muller-Landau, staff scientist at the Smithsonian Tropical Research Institute, says that understanding the …