written by: Kelley V Phillips, Outreach Coordinator
Trees have captured our imagination for generations. In our minds, they have a voice. Think of the crabby apple tree who fussed at Judy Garland in the Wizard of Oz or the sage yet sassy Grandmother Willow in the Disney classic Pocahontas. As it turns out, they do “talk,” just not to us.
Since the age of Darwin, trees have been treated as competitors. There were winners and losers when it came to nutrients, water and sunlight. New research has discovered that trees are far more social and cooperative than we once thought.
Anyone who has been in the woods can tell you the shushing staccato of leaves in the wind sounds like trees are talking. Perhaps they are whispering to one another about whose canopy is the grandest? Or if there is a deserving head that could use an acorn dropped on it? Surprisingly, the communication network actually lives within the soil beneath our feet.
It starts with a hub tree. These are often the oldest, tallest trees in a forest. Having top access to sunlight and well-developed deep roots, they often produce more sugar than they need. Hair-thin fungus that lives in the soil absorbs that extra sugar and in return provides nutrients to the tree’s roots. It’s a win-win.
The fungus is not limited to a single tree but stretches in a vast interconnected network between roots of surrounding trees. In a stand of Canadian Douglas Fir trees, one fir could be connected to more than 40 other trees. Researchers from the University of British Columbia who studied that Douglas fir patch found that a single teaspoon of forest soil contained several miles of the fungal filament.
The big question remains: what do trees “say” to each other? Mostly, alarm and distress. Through chemical and electrical pulses, they can signal disease, drought, pest infestations and browsing herbivores, like deer. Trees who receive the signals can alter chemicals in their leaves or bark to make them taste bad or create natural insect repellent.
The fungal network is not all talk. Hub trees are also known as “Mother Trees.” They support shallow rooted, sunlight deprived saplings with nutrients and share water in times of drought. The sharing system spans between different tree types too, not just those of the same species.
Roots are not the only way trees build alliances. Peter Wohlleben, a German forester and author of the bestselling “The Hidden Life of Trees: Why They Feel, How They Communicate,” suggests that trees have a sense of smell. Scent signals can be detected through leaves. His favorite example is when elms and pines come under attack by caterpillars, they release a scent that attracts parasitic wasps which kill the leaf-eaters.
Not everyone is on board with the idea that trees are building intentional relationships. While the fact they have an interconnected fungal system is undisputed, the argument is that the system is not a method of communication so much as just doing a job. Wolleben responds to that debate by saying he doesn’t actually think trees have consciousness, but they still have rights to be managed sustainably and respectfully.
Our understanding of the ways trees interact can help us manage stronger and more resilient woodlands. Even without scientific backup, closing your eyes and listening to a forest very much feels like a conversation. Who knows if we’ll ever be able to speak the language of trees, but as Grandmother Willow says, “Listen with your heart and you will understand.”
Kelley V Phillips is the Outreach Coordinator for Red-tail Land Conservancy. Her work in community engagement inspires excitement and wonder in nature through education and tangible experiences.