Older Trees Grow Faster

Mature trees soak up more CO2 than younger ones, a study shows, overturning a bit of botanical dogma.

Jan 20, 2014
Bob Grant

Giant camphor treesWIKIMEDIA, WITSTINKHOUTIt turns out that as a slew of tree species age, they grow faster and gobble up more carbon dioxide than when they were younger, according to a study published last week (January 15) in Nature. The findings, which involved decades of data taken from 673,046 trees in more than 400 tropical and temperate tree species around the globe, contradict a long-standing assumption that tree growth slows as the plants age. “The trees that are adding the most mass are the biggest ones, and that holds pretty much everywhere on Earth that we looked,” Nathan Stephenson, a US Geological Survey ecologist and first author of the study, told Nature. “Trees have the equivalent of an adolescent growth spurt, but it just keeps going.”

The results have important implications for conservation and forestry practices. “Not only do [older trees] hold a lot of carbon, but they’re adding carbon at a tremendous rate," Stephenson told NPR. “And that’s going to be really important to understand when we’re trying to predict how the forests are going to change in the future—in the face of a changing climate or other environmental changes.”