The trees are also growing fast—faster than expected for a “mature” rainforest—according to a network of measurements.
“When we measure that a particular stand of mature forest is accumulating carbon, it is difficult to say whether that might be due to recovery from some unrecognized disturbance long ago or whether it is due to more recent changes in climate and CO2,” explained Woods Hole Research Center Senior Scientist and Executive Director Eric Davidson, lead author of the review, in an e-mail. Candidates include recovery from the potential wide-scale disturbance by pre-Columbian human societies now beginning to be uncovered or the increasing availability of some formerly limiting factor, such as atmospheric carbon dioxide.
The good news is that Brazil has in recent years begun to restrain such deforestation: annual rates fell from 28,000 square kilometers in 2004 to less than 7,000 in 2011. “Brazil is poised to become one of the few countries to achieve the transition to major economic power without destroying most of its forests,” the researchers wrote in their conclusion. New laws currently under consideration may put that potential in peril, however, by allowing a return of previously banned forest-clearing practices. “There is considerable progress toward improved management of the impacts of development in the region,” Davidson noted in his e-mail, “but there is still much work to be done.”
