Trees have a much more social existence than we thought, according to new research by scientists from the University of Basel in Switzerland. It turns out that trees trade stored carbon between themselves, through the use of symbiotic fungi in the soil. Not only do they shift carbon from one tree to another, they can do this across species.


The researchers introduced marked carbon, which contained less of the 13C atom than normal carbon, into the crowns of spruce trees. The carbon made no difference to the trees, but could be traced by the researchers, who could trace it through the tree’s trunk and roots. They found that the carbon not only ended up in the roots of the targeted spruces, but also within the roots of neighboring trees that did not receive the carbon injection.

This is a pretty huge discovery, because it gives us another clue to understanding forest ecology. We’ve known for some time that trees can benefit from each other, and that they sometimes grow together into pretty unique shapes, but this evidence points to a much more concentrated effort on the part of trees to work together, so to speak.

Ecosystems consist of numerous plants and animals with intertwining lifecycles, which rely on each other in various ways for help. What we’re seeing with carbon trading, though, hints at something more akin to social animals like wolves or gorillas, which help each other out and work together for their own survival. The trees, which seem to know something we don’t, can trade carbon between each other to ensure that they get enough to grow, implying that trees developed the system to ensure each other’s survival. That survival goes beyond individual trees and to the entire forest, or at least sections thereof, though exactly how trees gain from that remains to be seen.