The chemist examined the role of activated oxygen molecules in biological processes.
Mature trees soak up more CO2 than younger ones, a study shows, overturning a bit of botanical dogma.
January 20, 2014|
WIKIMEDIA, 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.”
January 20, 2014
This is pretty much what you would expect. Bigger trees have more leaf area which means more photosynthesis which means more sequestration of CO2. A tree with a narrow trunk can only add so much cellulose around its periphery, and since it has fewer and smaller branches, the same applies there. Larger trees have a greater circumference and more and larger branches, so there is more room to add cellulose both in the trunk and in the branches. If you look at the tree rings, they are roughly the same thickness, but because they are bigger in diameter, the outside ones contain more substance.
January 21, 2014
This is an interesting and important item for many reasons, but as it appears in The Scientist it leaves me in doubt. That a big tree would occupy more biomass and that more live biomass would metabolise more energy and carbon is almost obvious, but a more important measure surely would be the amount of CO2 fixation per unit of land area per year.
Does the study address such questions?