’m walking in the Eifel Mountains in western Germany, through cathedral-like groves of oak and beech, and there’s a strange unmoored feeling of entering a fairy tale. The trees have become vibrantly alive and charged with wonder. They’re communicating with one another, for starters. They’re involved in tremendous struggles and death-defying dramas. To reach enormousness, they depend on a complicated web of relationships, alliances and kinship networks.
Wise old mother trees feed their saplings with liquid sugar and warn the neighbors when danger approaches. Reckless youngsters take foolhardy risks with leaf-shedding, light-chasing and excessive drinking, and usually pay with their lives. Crown princes wait for the old monarchs to fall, so they can take their place in the full glory of sunlight. It’s all happening in the ultra-slow motion that is tree time, so that what we see is a freeze-frame of the action.
My guide here is a kind of tree whisperer. Peter Wohlleben, a German forester and author, has a rare understanding of the inner life of trees, and is able to describe it in accessible, evocative language. He stands very tall and straight, like the trees he most admires, and on this cold, clear morning, the blue of his eyes precisely matches the blue of the sky. Wohlleben has devoted his life to the study and care of trees. He manages this forest as a nature reserve, and lives with his wife, Miriam, in a rustic cabin near the remote village of Hümmel.
Now, at the age of 53, he has become an unlikely publishing sensation. His book The Hidden Life of Trees: What They Feel, How They Communicate, written at his wife’s insistence, sold more than 800,000 copies in Germany, and has now hit the best-seller lists in 11 other countries, including the United States and Canada. (Wohlleben has turned his attention to other living things as well, in his Inner Life of Animals, newly issued in translation.)
A revolution has been taking place in the scientific understanding of trees, and Wohlleben is the first writer to convey its amazements to a general audience. The latest scientific studies, conducted at well-respected universities in Germany and around the world, confirm what he has long suspected from close observation in this forest: Trees are far more alert, social, sophisticated—and even intelligent—than we thought.
With his big green boots crunching through fresh snow, and a dewdrop catching sunlight on the tip of his long nose, Wohlleben takes me to two massive beech trees growing next to each other. He points up at their skeletal winter crowns, which appear careful not to encroach into each other’s space. “These two are old friends,” he says. “They are very considerate in sharing the sunlight, and their root systems are closely connected. In cases like this, when one dies, the other usually dies soon afterward, because they are dependent on each other.”
Since Darwin, we have generally thought of trees as striving, disconnected loners, competing for water, nutrients and sunlight, with the winners shading out the losers and sucking them dry. The timber industry in particular sees forests as wood-producing systems and battlegrounds for survival of the fittest.
There is now a substantial body of scientific evidence that refutes that idea. It shows instead that trees of the same species are communal, and will often form alliances with trees of other species. Forest trees have evolved to live in cooperative, interdependent relationships, maintained by communication and a collective intelligence similar to an insect colony. These soaring columns of living wood draw the eye upward to their outspreading crowns, but the real action is taking place underground, just a few inches below our feet.
“Some are calling it the ‘wood-wide web,’” says Wohlleben in German-accented English. “All the trees here, and in every forest that is not too damaged, are connected to each other through underground fungal networks. Trees share water and nutrients through the networks, and also use them to communicate. They send distress signals about drought and disease, for example, or insect attacks, and other trees alter their behavior when they receive these messages.”