By Angela Noel
June 8, 2017
When we first moved into our house I sat in my backyard gazing up at the canopy of tree branches overhead. Two trees, their trunks big enough around that two adults with arms outstretched couldn’t encircle them, blotted the sun. For reasons I cannot explain two names popped into my brain: Erin and Bertie. I told my husband and son the trees had names. Not that I had given them names, but that they already had them–like they’d accepted me into their community as one of their own. (Weird, I know.)
Among the oaks and cottonwoods that dot the rest of my little wooded lot, Erin and Bertie are special. A fact, Suzanne Simard, noted forest ecologist, professor, and TED speaker would find not-at-all surprising. Her work, and those of other researches around the globe, has opened up a greater understanding of the complex and beautiful world of tree interdependence. How trees communicate and contribute to the common good of the ecosystem in which they live has a lot to tell us not only about nature, but about ourselves as well.
Bertie is an elm tree, Erin, a silver maple. Beneath my feet, a network of mycorrhizal fungi and roots connect these two to each other, and to many of the other trees within what ecologists call a stand. (Of course, I call this stand, “my backyard.”) Through this network, they pass nutrients and information. Professor Simard proved this more than twenty-five years ago.
At first, people scoffed. But over time, her results and persistence in speaking about trees as having communication networks, has resulted in even more study of the mind-boggling complexity beneath the ground. For example other ecologists, like Richard Karban or Yuan Yaun Song seek to decode the alien language of trees and plants as they attempt to defend themselves and each other from invasive species and pests. A bestselling book by forest ranger Peter Wohlleben entitled, The Hidden Life of Trees: What They Feel, How They Communicate–Discoveries from a Secret World makes the case for reimagining trees as something more they may seem. The science speaks for itself: Trees are talking to each other–and to us. But what are they saying?
Certainly, competition for resources like sunlight and water seem obvious. The tree with the best access to the most resources grows the biggest and its offspring populates more of the forest, right? But that’s only part of the story.
While the trees reach for the sky, climbing higher and spreading farther, their roots are doing the same–but not always to squeeze out other trees–to nurture them. When one tree has an excess of a particular nutrient, it shares. When another tree is in trouble, because its been shaded too long or sustained an injury, it receives aid. It doesn’t have to be a related tree- it just has to belong. In other words, trees share within their community.
Trees form an interdependence with each other, regulated in some way by “mother” trees. These trees, unlike the Ents of Tolkien’s novels, are not tree herders. They don’t direct the behavior of other trees, so much as distribute the wealth. Their superior size and age, makes them repositories of knowledge the younger trees need. Without these hub trees, forests suffer. The presence of hub tree weakens disease outbreaks and pest infestations. Mature trees, though, do not live forever. There must be young ones to pass their knowledge on to. All forests need variety in species and in age. They need diversity and a chance to thrive. However, not all trees get along.
Interestingly, according to Professor Simard’s research, some trees don’t participate in the underground network. Professor Simard’s hypothesized a Douglas fir replicant and a paper birch would communicate. But a western redcedar would be in “its own world.” In her experiment, the redcedar received no nutrients and no communications from the other trees. Yet, fir and redcedar share forest space in Oregon. So, what’s going on? Why can’t fir, birch, and redcedar get along in Simard’s experiment?
One reason may be the fungal networks that form the interconnected webbing of the “wood wide web,” can be selective. Some fungi are generalists, others are more particular, pairing only with certain plants. In Simard’s experiment, the fungal network–the link to understanding each other–may not have included the right biological language for redcedar.
Forest communities can teach us a great deal about the wonders of
interconnected relationships, and the importance of sharing resources for the good of all. But they are–in the end–trees. A tree, even one as special as Erin or Bertie, can’t bridge the distance between a tree whose fungal language it recognizes and one it doesn’t. And yet, humans can. Humans, I think you’ll agree, can be smarter than trees. As smart, at least, as the generalist fungi that connect the biologically diverse forests we live in, near, or around.
But we aren’t sometimes. And that’s a shame.
I’d like to think that if given the choice, Bertie and Erin would step up to the challenge. They, and their generalist fungi would invite a western redcedar to a dinner of carbon dioxide, nitrogen and phosphorus. But, I wouldn’t expect that of them. But I do expect it of myself. The next time I meet someone who doesn’t seem to be a part of my world, I want to find out the ways we’re the same. And the ways we can share our knowledge, to build a stronger, more resilient world.
Your turn: What are the best ways to help someone integrate into a community? How do you create connections?