I am re-reading The Hidden Lives of Trees by Peter Wohlleben. A certified forester in Germany, he manages a forest for the municipality of Hümmel, next to the Eifel mountains. The book is a scientific walk through a forest.
There is something mystical about forests. The first thing that I notice is their stillness. In a forest, I am no longer accosted by someone’s taste in music. I experience the healing power of silence, and with that silence, the heightening of forest sounds. A lone bird’s call, a branch cracking and falling, the scratching sounds squirrels make as they rummage around the forest floor.
Time seems slower in a forest. Trees in forests live much longer than their counterparts. The mature trees are centuries old. Their lives are slower, more deliberate, more adaptable.
For trees to live long and healthy lives, they must grow slowly. And the forest helps them do this. Only one offspring will fully mature from the hundreds of thousands of seeds of the parent. Most seeds are food for insects and forest creatures. Some seeds become saplings, but competition, weather, and damage by the larger forest residents ensures that only one survives. The winning sapling grows slowly, patiently waiting for the adult tree (usually its parent) that shadows it to slowly die or become toppled by man or a weather event. By restricting light, the parent allows the sapling to grow slowly and become strong. But these light restrictions make it is hard for the sapling to get enough food, so neighboring trees provide water, food and nutrients. It takes a forest to grow a sapling.
Wohlleben sees trees as social creatures. They communicate with each other, they care for each other, sometimes nourishing a stump for centuries. Trees communicate at a slow pace, sending warning signals about predators via scent, sounds, or through the mycelial fungi network.
The fungi network lives underground. The fungi connect with trees using tiny threads of fungi called mycelium which wrap around and invade the tree root. The fungi take nutrients from the soil and transfer them to the tree. These are nutrients that roots could not otherwise absorb. In return, the tree provides carbon to the fungi. The mycorrhizal network (the fungi network) retains about 30% of the sugar that its connected trees generate through photosynthesis. The sugar fuels the fungi, which in turn collects phosphorus and other mineral nutrients into the mycelium, which are then transferred to and used by the trees. A perfect symbiosis.
The mycelial (fungi) network spreads and links trees (nicknamed the “wood wide web”) via their tree roots. Wohlleben believes that some of the socializing between trees occurs through this wood wide web. Healthy trees send food, water, carbon, and nutrients to connected suffering trees. Trees appear to show preference for their own species.
There is some scientific evidence for his theory. A study on Douglas-fir trees at England’s University of Reading, suggests that trees may recognize the root tips of their relatives and favor them when sending carbon and nutrients through the fungal network.
As fungal filaments spread out through forest soil, more and more trees become connected. Older trees have the most connections and they are the trees most likely to assist other trees. Called Mom or hub trees, Wohlleben believes that these trees are critical to the survival of trees in the network.
In his book, Wohlleben also explains how trees grow, how they protect us, how coastal forests prevent deserts, and how the forest nourishes itself.
The first time that I read this book, I was mesmerized by the concept of this fungi network. The movie Fantastic Fungi also popularized this concept of how trees communicate via this network.
But is it true?
I wanted it to be true, the idea of a natural connection in nature seemed so special. Popular science writers and even scientists were equally entranced with an idea that opened their imaginations.
But recently, three scientists have suggested that claims that fungi networks allow trees to communicate are based on misinterpretation and overinterpretation of data.
Of 28 experiments designed to answer this question, this connection was only found in 18% of them. And there were other possible explanations for the relationship (e.g., soil). Other widely reported claims: that trees use these networks to signal danger, or recognize offspring, or share nutrients with other trees, are not supported by the data.
Like most things in science, we are limited by measurement, there may be connections that we cannot measure, wavelengths that we cannot perceive, energies that we do not understand. Lab studies have found connections and communications among other plants through fungi networks; but trees move so slowly (think in centuries); that we may not have the tools to capture the relationship.
What is true is that the fungi connection between trees and the soil is critical for tree survival, but whether it aids trees in connecting with each other is not so certain.
While science has progressed slowly, our imaginations have not. So even if some statements in The Hidden Lives of Trees have not been scientifically verified, the author’s knowledge and reverence for the forest still inspires my imagination.
As a child, we used to walk in the forest with our father at Christmastime looking for mistletoe, crow’s feet, and holly branches. On occasion, a blanket of snow made the woodlands seem even more magical.
So, whether or not the wood wide web is true, the forest is still a mystical, mysterious place.
Angela Rieck, a Caroline County native, received her PhD in Mathematical Psychology from the University of Maryland and worked as a scientist at Bell Labs, and other high-tech companies in New Jersey before retiring as a corporate executive. Angela and her dogs divide their time between St Michaels and Key West Florida. Her daughter lives and works in New York City.