For Peter Wohlleben, trees and humans aren’t so different

From nursing sick neighbours to taking care of saplings, a ‘Wood Wide Web’ is fuelling personal connections in the forest
Peter Wohlleben, Foerster und Buchautor, vor Buchen und Fiechten in seinem Forstrevier. Portraet, Einzelportraet. Europa. Deutschland, Rheinland-Pfalz, Eifel, Huemmel. 29.09.2015.
Peter Wohlleben, Foerster und Buchautor, vor Buchen und Fiechten in seinem Forstrevier. Portraet, Einzelportraet. Europa. Deutschland, Rheinland-Pfalz, Eifel, Huemmel. 29.09.2015.
Peter Wohlleben, Foerster und Buchautor, vor Buchen und Fiechten in seinem Forstrevier. Portraet, Einzelportraet. Europa. Deutschland, Rheinland-Pfalz, Eifel, Huemmel. 29.09.2015.

Even small children know trees are living beings, says Peter Wohlleben, despite the fact you can burn them up in a cozy log fire. An amiable forester and the author of The Hidden Life of Trees, a bestseller in his native Germany—a country where forests are sunk deeply into the cultural DNA (think Grimms’ fairy tales)—Wohlleben is not morally troubled by the consumption of trees. Or of animals, for that matter, as long as they are all treated with respect, in a way “appropriate to their species,” including allowing some “to grow old with dignity and die a natural death. I’ve tried to show how animal- and even human-like trees are, to feel them empathetically.”

That’s why the trees in Wohlleben’s book, released in English in 2016, are anthropomorphized to a degree that infuriates scientists and delights hundreds of thousands of readers. “I am a human being, I use human language. Scientific language is full of insight and fascinating facts, but take the emotion out of your speech and the people you are talking to don’t feel what you are saying,” Wohlleben says in an interview. Thus his trees are both individuals and social beings: they nurse sick neighbours, lavish love and attention on their children, and even at times take care of their dead—keeping stumps alive through a sugar solution delivered from their roots to the stumps. The trees “talk” to each other, warning about pests and changes in the weather; they learn from experience and feel pain when injured. Deadwood they are not.

The effect on readers is utterly charming, but what keeps the experts grumbling well short of denunciation is that Wohlleben also has the science down. For a quarter-century, research, much of it conducted in Canada’s West Coast rainforests—Suzanne Simard, a forest ecology professor at UBC, is quoted often and supplies an afterward to Hidden Life—has revealed the existence of the electrically alive fungal-root network now known as the Wood Wide Web. In British Columbia, where Simard has traced that web across species boundaries, birches and Douglas firs supply each other with carbon and nutrients, while taking seasonal turns as the dominant partner in the exchange. Tree “communication”—Simard writes as a professional—is now an established fact.

Wohlleben, 52, might not sound the same, but he too is a trained professional. He grew up in the 1970s in Bonn, then the capital of West Germany, when environmentalism was starting to become a mass national movement. He became a forester, he says, in part to save the world, though the forestry agency’s paid internship didn’t hurt. By 1987, Wohlleben was running a 1,200-hectare reserve in the Eifel region, near the Belgian border. “I followed all the normal practices, just as I was taught: the clear cuts, the machine logging, spraying insecticides. But I didn’t want to—I knew inside it was killing the forest.”

He became fixated on the way nearby private forests, in operation for hundreds of years, were not only run with ecological sensitivity, but made more money, because their trees were older and larger, and their operating costs so much lower. “Yes, it’s true, what I said, well mostly,” laughs Wohlleben when asked about one controversial remark. After adding a few qualifiers, he’s happy to repeat himself: “Two very big, very high-quality trees from an old family forest will buy you a car; two spruce from a state forest isn’t worth more than two, okay, three pizzas.”

Eventually, fed up with his working life, Wohlleben talked the local municipal council into supporting doing things that way, with an additional twist: burial plots. For a fee, people could bury urns containing the ashes of their cremated loved ones under centuries-old trees bearing a name plaque, reducing the timber-felling required to turn a profit.

But he couldn’t get permission where it mattered, at the state forestry agency, so after 15 years, Wohlleben quit his job. He, his wife and two children were going to emigrate to Sweden, in hopes of finding better forestry practices, when “the mayor said he’d break the arrangement with the government and hire me directly. Now I was free to do what my heart told me.”

So far, everyone is happy. There is less timber revenue—it will be a long time before Wohlleben can sell many trees worth half a car each—but costs are way down. He no longer uses expensive chemicals or machinery: all harvested trees are removed by horse power. And the “living gravestone” business is booming. “This is a Catholic area and the Church was very opposed at first, but not now. We already have 4,000 urns in the forest, with room for another 20 years of demand.” Within two years of the switchover, the sustainable forest was earning a handsome profit, while creating six new jobs.

Excerpt: How trees talk to one another

Commercially and professionally vindicated, Wohlleben speaks confidently, in his human language, about his rather human trees. He’s seen the negative side of the Wood Wide Web: Twice Wohlleben has come across lightning-struck Douglas firs—the North American transplant is a staple of German commercial forests—and found, within a 15-m radius, other dead Douglas firs, “electrocuted” at the same time via their underground connection to the original victim.

The positive side, what Wohlleben calls the trees’ commitment to social security, far outweighs the negative. In an undisturbed beech wood, the trees synchronize their photosynthesis so that each ends up growing “into the best tree it can be.” That cuts against foresters’ instinctive belief that the trees are competing against each other, but mutual support actually makes evolutionary sense. Many trees make for, well, a forest, and a forest—through its climate control—is on the whole a better environment for a tree, just as village life beats living alone for most people.

So far, even the least sentimental forester can nod along, but why would a stand of beeches in his forest keep providing nutrients to a stump, which by definition is no longer holding up its end of a social security regimen? Especially a stump that Wohlleben judges, by the disintegration of its central core, to have fallen “at least 400 years ago?” It doesn’t happen often, he acknowledges, and never under commercial harvesting conditions. Perhaps, Wohlleben speculates—and he is always careful to note when he is about to step outside expert consensus—it indicates “friendship and affection” between trees, more a matter of grave-tending for an honoured member of the community than an evolutionary strategy.

Affection doesn’t seem a step too far for Wohlleben, given what he calls the “individual characters” of trees. He likes to point to a trio of oaks sharing the exact same growing conditions. One, out of “anxiety,” he says, always drops its leaves weeks before the others, responding each fall to the decreasing hours of daylight rather than to the increasing number of warm days brought by climate change. A tree in full leaf, unable to let strong winds pass right through its canopy, is in danger of being toppled in a seasonal storm. Usually a sunny optimist, Wohlleben thinks the anxious tree has it right—sooner or later, the two laggards, greedy for maximum photosynthesis, will pay the price in an autumn gale.

But nothing brings out emotive language like the relationship between tree parents and their offspring. When Wohlleben took a close look at the number of tiny annual nodes on beech saplings that were between one and two metres tall, he realized that trees he had assumed to be no older than 10 were actually closer to 80. Given their growing capacity, the young beeches could have been 35 m taller. Why then were they so stunted? Because, the forester answers in deliberately chosen terms, “their upbringing prevents it for their own good.”

They stand under 200-year-old mother trees, whose canopies block 97 per cent of the sunlight. That leaves just enough to keep them alive, when bolstered by sugar and other nutrients passed on to their roots by mothers “nursing their babies,” as Wohlleben calls it. For decades then, energy not spent on growing taller is diverted to squeezing the air pockets out of inner cells, making the saplings both more dense and more flexible. That sets them up for a lifetime of storm protection and resistance to pests and injuries. When their elderly parents ultimately topple to the ground, the well-raised saplings—those that survive the crash, that is—race each other to fill the sun-drenched opening in the canopy.

In the end, it’s the slow pace of tree life that stops us from treating them with the respect they deserve, argues Wohlleben. We can appreciate the surprising and intricate mutual support network, and accept (or not) the maternal love idea, but ultimately trees simply “exceed the human attention span.” People do want to help, he says, but they want results. “It’s hard to accept that helping means keeping our hands in our pockets, letting all the ugly, slow death and messy regrowth go on for 500 years.” It needs to be done, though, Wohlleben adds, because forests are crucial, “in making our world the kind of place where we want to live.”