Environment
Drought's Lasting Effect on Trees Spells Danger for Carbon Levels
Shrinking tree rings point to a worrying future for forests and humans, a new study finds.
As kids, we learn that a tree’s rings tell its age: one for every year.
But scientists also know that tree rings are a ledger for climate data. Their width speaks to temperatures surrounding the tree, the abundance of light, average rainfall and ground moisture. During wet years, rings tend to be wider. In dry times, they tend to shrink, stunting the tree’s overall growth. And according to a new paper in Nature, rings also tell us that most trees don’t immediately bounce back from periods of drought—a fact that may one day seriously compromise forests’ capacity to store carbon.