Environment

Regrowing Rain Forests

Scientists have long promoted rain forest preservation as a way to mitigate climate change, but now it turns out that regrowing forests is just as important.

Newly grown tropical forests can capture harmful carbon from the atmosphere at a rate up to 11 times faster than older forests, according to a study published in the journal Nature on Wednesday. The study includes a map of Latin America (pictured below) that shows the regions with the greatest potential for carbon capture.

The researchers examined the biomass recovery of young "secondary" tropical forests, which are less than 100 years old, and compared it with that of “old-growth” forests, which are at least a few hundred years old. They looked at 45 forest sites of varying ages across Central and South America, which involved measuring more than 168,000 trees in all.

This data allowed the researchers not only to build the map, but also to analyze how much carbon secondary forests can take up -- which turned out to be more than expected, said Dr. Saara J. DeWalt, an associate professor of biological sciences at Clemson University in South Carolina and a co-author of the study.

"I was very surprised by how quickly secondary forests uptake carbon," DeWalt said. "Younger forests capture more carbon because the trees are actively growing and are quickly converting carbon into leaves and wood. Growth of trees in older forests is much slower because of more limited space, sunlight and nutrients."