BioEd Online

If deforestation continues at its current pace, only small and isolated patches of tropical forest will survive half a century from now.

Agriculture, logging and urbanization have chopped great swathes of tropical forest into fragments, disrupting habitats and reducing biodiversity. To assess the damage, Franziska Taubert of the Helmholtz Centre for Environmental Research in Leipzig, Germany, and her colleagues studied high-resolution satellite images, which revealed more than 130 million fragments of tropical forest across 3 continents. Sections smaller than 10,000 hectares account for roughly 10% of forests.

The researchers also found that tropical forests are nearing a critical point. If deforestation continues, runaway fragmentation will lead to an explosion in the number of forest segments, and average size will plummet from 17 to 0.25 hectares over the next half century.

Tree clearing should be slowed and reforestation increased to restore tropical-forest cover in the next few decades, the authors say.