In an early version of a now-famous passage, John Muir wrote, “When we try to pick out anything by itself we find that it is bound fast by a thousand invisible cords that cannot be broken, to everything in the universe.” New research is proving the great conservationist right in ways even he could not have realized.
We’ve long known that trees whose roots touch and connect can exchange nutrients, and that linking into vast underground networks of fungi known as mycorrhizae (which appear on the surface only as innocuous mushrooms) enable trees to grow far faster, but some emerging research is beginning to discover the extent of these connections. The fungal web that allows a tree access to far more nutrients than its roots alone can gather also connects trees to one another, both within and across species. In one particularly cool example of this type of mutualistic relationship (one in which both creatures benefit from one another), research in the Douglas fir forests of British Columbia shows that trees provide one another with needed carbon during times when one species’ productivity is low– Douglas fir trees share with birches during the spring and fall, when the deciduous trees are leafless, while regenerating firs get the benefit of the birches’ excess carbon during the summer months.
New techniques to visualize these underground workings will only help further our knowledge, with potentially great implications for conservation. By providing a huge boost in growth to young trees, these networks may help species with the rapid migration they may need in the face of a quickly-changing climate. Because old trees serve as the hubs of these networks, with younger trees tapping into their resources, understanding the networks may provide an incentive for forest managers to keep the oldest trees in a stand after harvesting for the benefit and productivity of the whole forest.
There is far more to these interactions than can be explained in this short piece, but if nothing else, it gives comfort to know that in an ecological paradigm in which competition is seen to be the dominant force driving forest processes and development, sharing and cooperation still play a vital role.