A team of researchers from the University of Melbourne has discovered that old trees are better at storing carbon dioxide than young trees. The study revealed that tree growth rates increase continuously with size, and that large older trees are capable of adding the carbon mass equivalent of an entire smaller tree each year.
The research was published in the journal Nature. Associate Professor Patrick Baker, an ARC Future Fellow at the Melbourne School of Land and Environment said, “Our research shatters the long-standing assumption that tree growth declines as individuals get older and larger. However, the rapid carbon absorption rate of individual large trees does not necessarily translate into a net increase in carbon storage for an entire forest.”
Dr Adrian Das, an ecologist from the U.S Geological Survey who was working with the Australian team on the project, added, “Old trees, after all, can die and lose carbon back into the atmosphere as they decompose. But our findings suggest that while they are alive, large old trees play a disproportionately important role in a forest’s carbon dynamics. It is as if the star players on your favorite sports team were a bunch of 90-year-olds.”
For the study, the research team measured the growth of 673,046 trees belonging to 403 species from tropical, subtropical and temperate regions across six continents. “What makes these results so compelling is the sheer scale of the datasets that we had available to work with,” said Associate Professor Baker.