Peter Wohlleben

The Hidden Life of Trees

“The average tree grows its branches out until it encounters the branch tips of a neighboring tree. A pair of true friends is careful not to grow overly thick branches in each other's direction.”

Duck down, watch your head. You’re entering a forest. There is no horizon and the scenery is arms-reach. This is a unique space as close to human-conceived landscapes as anything, born of a single acorn (Emerson reminds us and Robert Macfarlane enchants us).

But a forest is more than a miraculous abundance of life. As graciously illustrated in Peter Wohlleben’s (born 1964) The Hidden Life of Trees, a forest is a community.

Tree studies, photograph by Ellen Vrana. Used in Wendell Berry's "Our Only World" on the Examined Life Library.
Tiergarten Park, Berlin. Photograph by Ellen Vrana.

Wohlleben is a career forester, a steward of space where imaginations are sewn and fertilized and the earth’s critical atmospheric balance restored. It’s hard to imagine that his absolutely mind-tickling book, The Hidden Life of Trees is not his master work but it is not, the forest he protects, is.1

The book was born of extraordinary life, Wohlleben’s and the community of trees for which he cares.

When I began my professional career as a forester, I knew about as much about the hidden life of trees as a butcher knows about the emotional life of animals. The modern forestry industry produces lumber. That is to say, it fells trees and then plants new seedlings. If you read the professional literature, you quickly get the impression that the well-being of the forest is only of interest insofar as it is necessary for optimizing the lumber industry. That is enough for what foresters do day to day, and eventually it distorts the way they look at trees. Because it was my job to look at hundreds of trees every day-spruce, beeches, oaks, and pines-to assess their suitability for the lumber mill and their market value, my appreciation of trees was also restricted to this narrow point of view.

Photograph by Ade Parker, featured in Peter Wohlleben's "The Secret Life of Trees" in the Examined Life Library.
“Pedunculate Oak, many hundreds, if not thousands, of children have played on the low branches of this old oak tree over the years and hopefully some of the magic of being up close and personal with old trees will have rubbed off. It’s probably about 250 years old and 4.6m around.” Photograph and notes by Adrian Parker, a dendrophile who photographs the wonderful old trees in The New Forest (Hampshire, UK) for posterity.

Wohlleben shows us trees as beings, not self-cognitive beings, that gift is reserved for humans and some rather brilliant animals, but beings that possess cognition about their environment and each other in a way that might astound you.

Tree roots extend a long way, more than twice the spread of the crown. So the root systems of neighboring trees inevitably intersect and grow into one another-though there are always some exceptions. Even in a forest, there are loners, would-be hermits who want little to do with others. Can such antisocial trees block alarm calls simply by not participating? Luckily, they can’t. For usually there are fungi present that act as intermediaries to guarantee quick dissemination of news. These fungi operate like fiber-optic Internet cables. Their thin filaments penetrate the ground, weaving through it in almost unbelievable density. One teaspoon of forest soil contains many miles of these “hyphae.” Over centuries, a single fungus can cover many square miles and network an entire forest. The fungal connections transmit signals from one tree to the next, helping the trees exchange news about insects, drought, and other dangers.

A viral network of information, sent, received, understood… isn’t that all we are? The basis of life is a membraned cell that communicates with its environment, Nobel Prize-winning geneticist Paul Nurse instructs in his guide to life’s basic yet essential components.

Photograph by Ade Parker, featured in Peter Wohlleben's "The Secret Life of Trees" in the Examined Life Library.
“One of the majestic Beech pollards at Vinney Ridge, Hampshire. Probably about 350-400 years old and about 4.4m circumference.” Parker volunteers as a verifier for the Woodland Trust, recording new trees for the Ancient Tree Inventory or verifying other recorders’ findings.

Do not be deceived however, a forest is more than a collection of trees.2 I use the word “community” quite deliberately.

A tree is not a forest. On its own, a tree cannot establish a consistent local climate. It is at the mercy of wind and weather. But together, many trees create an ecosystem that moderates extremes of heat and cold, stores a great deal of water, and generates a great deal of humidity. And in this protected environment, trees can live to be very old. To get to this point, the community must remain intact no matter what. If every tree were looking out only for itself, then quite a few of them would never reach old age. Regular fatalities would result in many large gaps in the tree canopy, which would make it easier for storms to get inside the forest and uproot more trees. The heat of summer would reach the forest floor and dry it out. Every tree would suffer.

Echoing Wendell Berry’s life-summing line: “There has always been a higher seeing that informs us that parts, in themselves, are of no worth” Wohlleben explains how this community transpires in the forest and underlines all life:

If trees are weakened, it could be that they lose their conversational skills along with their ability to defend themselves. Otherwise, it’s difficult to explain why insect pests specifically seek out trees whose health is already compromised. It’s conceivable that to do this, insects listen to trees’ urgent chemical warnings and then test trees that don’t pass the message on by taking a bite out of their leaves or bark. A tree’s silence could be because of a serious illness or, perhaps, the loss of its fungal network, which would leave the tree completely cut off from the latest news. The tree no longer registers approaching disaster, and the doors are open for the caterpillar and beetle buffet. The loners I just mentioned are similarly susceptible-they might look healthy, but they have no idea what is going on around them.

Photograph by Ade Parker, featured in Peter Wohlleben's "The Secret Life of Trees" in the Examined Life Library.
“I’ve known of this tree for a long time but because it is quite close to where I live I’ve never been to see it, for some strange reason….what a mistake! It’s a beautiful old tree, full of character. Probably about 350-400 years old and about 6m girth.” Photograph and notes by Adrian Parker.

Set against the context of today’s ever-sparcing land and felled once-grandeurs of the forest, Wohlleben’s observations make an articulate argument that it is the community of trees that need protecting and nurturing, not merely individuals.

More than a hundred years ago, oak forests were planted on the Lüneburg Heath on what had once been arable land. It would take only a few decades for the original framework of fungi and bacteria to settle the soil once again-or so the scientists assumed. But far from it. Even after this relatively long time, there are still gaping holes in the species’ inventory, and this deficit has grave consequences for the forest, as the nutrient cycles of birth and decay aren’t functioning properly. Moreover, the soil still contains excess nitrogen from the fertilizers once used there. True, the oak forest is growing more quickly than similar stands of trees located on ancient forest soil, but it is markedly less robust when it comes to issues such as drought. We don’t know how long it will take until true forest soil is created once again, but we do know that a hundred years is not enough.

While reading through Wohlleben’s work, I returned many times to Emerson’s dictum: from a single acorn, a thousand oaks. True, yet how limited this is in terms of the forest. Transcendental thought like Emerson, Thoreau and Whitman might have influenced our modern oneness with nature (rather than seeing it as an other) but they do little to bend our minds towards its salvation.

Three hundred years to grow,
three hundred more to thrive,
three hundred years to die –
nine hundred years alive.

From Robert Macfarlane’s incantation “Oak” in The Lost Spells

For that, we need life-science, tree-science and tree-stewards like Wohlleben.

Pair this mind-opening book with Robert MacFarlane’s search for nature outside society and beyond our comprehension, Annie Dillard’s sojourn into self through the wild, Rilke’s incantations to the nature spirit, to Wendell Berry’s exquisite insight on the intrinsic value of the wholeness of nature.



The photographs in this post hold centuries of life in leaves and bark. These perpetual giants were noticed and recorded by the passionate dendrophile Adrian Parker who volunteers as an ancient tree verifier in his spare time. Learn more about the UK’s society of elders here.