Back in 1999, scientists at Switzerland’s University of Basel began an experiment to see how trees would handle the large amounts of carbon dioxide we’re releasing into the air. In so doing, they stumbled onto the unexpected discovery that trees exchange carbon with one another, even when they’re not directly connected. This “wood-wide web” could totally alter the way we understand forest interactions.
The scientists fumigated five spruces for several years, giving them a particular type of carbon, carbon-13, so they’d be able to track the movement from the tree canopy to the roots. Yet when they went to measure how much carbon-13 had traveled through individual trees, they found the substance in the roots of nearby trees as well, even ones that weren’t spruces.
Not quite believing what they were seeing, the scientists ran several tests to see if they could find carbon-13 in other plants. It wasn’t present in the leaves of neighboring trees, meaning it definitely was being passed through the roots. At times roots graft together, but this wasn’t the case with these trees; they weren’t connected. Trees can also pass carbon into the soil, so other trees could absorb it then, but that wasn’t the case either – herbs growing around the trees didn’t contain any of the carbon-13.
The carbon-13 did show up in tree root fungi. Nearly all trees have a fungi called mycorrhiza on their roots, which scientists knew exchanged nutrients and carbon between trees. They didn’t know that mycorrhiza would pass simply carbon – in rather large amounts – creating an underground network.
The scientists published a study of their discovery, and now it’s time for more research. They want to know if trees pass carbon from stronger to weaker trees, or vice versa. Could trees work together to increase the resilience of a forest in a disaster?
Via The Atlantic