"Hidden Life of Trees" Book Review (Linda Thompson)
THE HIDDEN LIFE OF TREES
What They Feel, How They Communicate
Discoveries from a Secret World, by Peter Wohlleben
The Hidden Life of Trees by Peter Wohlleben is among the most awakening books I have read. Wohlleben, scientist, forester, and manager of a nature reserve in the Eifel Mountains of central Germany, values trees and especially forests not only for their material resources and symbiotic relationship with the human community, but also as ecosystems, interwoven and interdependent, supporting tens of thousands of species living within the forest compounds — species necessary for life, but which could not exist outside the forest environment.
He reports that one scientist counted 2,041 spiders and insects belonging to 257 different species living in the crown of a single majestic tree in the Bavarian Forest National Park. This tally does not include fungus, bacteria, and microbes living in the bark and root systems, and only includes those critters tumbling to the forest floor after being sprayed with insecticide. (p. 132)
Trees breathe through their leaves, trunks and roots. During the day when trees are photosynthesizing, they exhale oxygen and breathe in carbon dioxide. At night they do the reverse. Every day in summer, trees releases about 29 tons of oxygen per square mile of forest. A person breathes in nearly 2 pounds a day — so trees per square mile provide the daily requirement for about 10,000 people. (p. 224) Trees store up to 22 tons of carbon dioxide in their trunks, branches and root systems. Some carbon dioxide returns to the atmosphere after a tree’s death, but most of it remains locked into the ecosystem forever. (p. 93)
The Hidden Life of Trees is filled with facts and figures extolling the benefit of trees to the environment; these data can be found in other resources as well. What I found particularly awakening is the beauty of Wohlleben’s presentations, made understandable and relevant by his comparing the life of trees and forests to the human family and community. Upon completing the book, I felt that I had read a social critique extolling the interrelationships of humanity as clarified by the symbiotic interrelationships of the forest. The need for community appears endemic to life.
Wohlleben believes that trees should be appreciated for their own sakes; they are among the oldest living creatures on earth. His management of an old forest preserve near the remote village of Hummel, Germany has convinced him that trees experience pain and have memories, that tree parents live together with their children whom they nurture through root and fungal networks and protect by their canopies and sturdy branches. Trees, like humans, thrive in community and struggle when isolated away from like species.
Wohlleben tells us that, contrary to popular thought, trees grow better when crowded, with their trunks barely 3 feet apart. In this way they form alliances with trees of their own and often other species, developing interdependent relationships, a collective intelligence, defense mechanisms, supports systems for weak or endangered members, and a common means of nurturing their young and shaping future generations. When supportive of one another, each tree has its best shot of reaching its full potential. Some such as the oak live hundreds of years; others can live thousands. The Dalarna Swedish spruce is thought to be 9,500 years old. (p. 207) The social contract Wohlleben describes between the trees and their supporting ecosystems is reflective of the social contract valued by our human community. We all live best in community. Alone, we desiccate.
Below are listed a few of Wohlleben inductions:
1. Trees communicate through the production of scent excreted by leaves and carried on the breeze to other trees. A favorite example of inter-tree communication involves giraffes eating acacia leaves on the African savannah. (p. 7)
2. Some trees can taste and identify the saliva of certain insects eating their leaves or penetrating their bark and can release pheromones that attract beneficial predators that devour harmful insects. (p. 8) Perhaps this process would indicate that trees have memories and intellect, thereby enabling their survival when confronting pain or danger.
3. Trees of a common species share resources through their root and fungal systems. Wohlleben compares this sharing to “the way social security systems operate to ensure individual members of society don’t fall too far behind.” (p. 16) A moving example of this is given in the “Friendships” chapter in which Wohlleben describes how a trunk, with a diameter of 5 feet, felled at least four or five hundred years ago, was still alive, sustained by neighboring trees through the transmission of food either through their root or fungal network. (p. 2) Wohlleben compares this support to the care elephants give to their weak and sick, enabling them to recover and return to the herd, hesitating even to abandon their dead. Unable to determine why the forest has kept the old stump alive, Wohlleben postulates that perhaps the giant tree had been the mother of surviving trees, who now return the care earlier received. Species that live in social groups belong to a community that will look after it in times of need, warn it of impending dangers, and feed it when it is sick or in distress.
4. (Loner) Trees can suffer greater damage during winter storms, especially during heavy snow, ice, and wind swirls. Branches can be broken, crowns stripped, and trunks snapped. “The less integrated the tree is in a community of its own species, the greater the danger. Loners standing unprotected fare less well than well-connected individuals in a dense forest who can lean on their neighbors for support.” (p. 205)
5. A high diversity of species stabilizes the forest ecosystem. The more species there are around, the less chance there is that a single one will take over to the detriment of the others. (p. 130) There are more life forms in a handful of forest soil than there are people on the planet. A mere teaspoon contains many miles of fungal filaments. All these work the soil, transform it, and make it valuable to the trees; in turn, they create a habitat suitable for themselves. (p. 86) The relationship is symbiotic. Lifeforms in the ecosystem are interdependent. Most animals that depend on trees don’t harm them. They just use the trunks or crowns as places to live and frequently benefit the livelihood of the tree and the forest ecosystems. (p. 131)
Wohlleben uses many other examples to show that trees think, remember, empathize, experience pain, and greatly benefit life. His sensitivity causes us to rethink the common rhetoric. Perhaps a review of our own understandings is in order. After all, we are part of the world-wide-web-of-life. Let us value one another, respect creation, and in doing so, respect the Maker of us all.
Linda Thompson is a member of First Baptist Church of Austin, TX, and an active leader on the church Green Team, co-managing an educational display and small item recycling facility for the entire congregation year-round, and contributing in numerous other ways. Read more of Linda’s writing here.