Review: The Hidden Life of Trees

Here’s an ancient idea: trees are sentient, social beings that communicate, recognize family members, learn and remember, adjust their behaviour and support each other through hard times. It’s an idea that speaks to the mystical within us, an idea we once learned, through myth, fable or aboriginal spirituality, and then unlearned, through religion or science. And now we can learn it all over again, in a way that turns the world around us into a place that’s new and exciting, but also comforting and familiar.

German forester Peter Wohlleben has pulled together two decades of scientific research and a lifetime of observing and tending the forest to explain in simple terms that yes, it’s true, trees have intelligence and feelings, they can demonstrate intra-species friendship, and experience pain and fear. Wohlleben, already a well-known author in his native land, has vaulted onto international best-seller lists with The Hidden Life of Trees: What They Feel, How They Communicate — Discoveries From a Secret World, the first of his books to be translated into English. In Canada, the book is published by Greystone Books in partnership with the David Suzuki Institute.

There’s an important Canadian connection: One of the scientists who has blazed a trail of understanding through the forest is Suzanne Simard, an ecologist at the University of British Columbia. In a contribution to Wohlleben’s book, Simard describes how, in the early 1990s, while searching for clues to the remarkable fertility of the inland temperate forests of the Pacific north-west, she unearthed a constellation of fungi linking many tree species. The discovery was the result of noticing that Douglas fir seedlings in clear-cut plantations declined when paper birch volunteers were weeded out. “This pattern of premature death had been concerning me for some time,” she writes. “The loss of synergy between broad-leaved trees and conifers, it turns out, was a concern of Peter’s, too. Across the forests of Europe, planting and weeding to create clean rows has been practiced for centuries.”

Using microscopic and genetic tools, Simard peeled back the forest floor to discover a vast below-ground fungal network. “When the interwoven birches and firs were spiked with stable and radioactive isotopes, I could see, using mass spectrometers and scintillation counters, carbon being transmitted back and forth between the trees, like neurotransmitters firing in our own neural networks.” She writes that she was staggered to discover that Douglas firs were receiving more photosynthetic carbon from paper birches than they were transmitting, especially when the firs were in the shade of their leafy neighbours. The exchange between the species turned out to be dynamic, each taking different turns as ‘mother,’ depending on the season. “And so, they forged their duality into oneness, making a forest.” This discovery was published in 1997 by Nature, which dubbed the network Simard had discovered the “wood wide web.”

This is a book of as great importance in our relationship to the world around us as was Doug Tallamy’s Bringing Nature Home a decade ago. It’s a re-introduction to an old friend we thought we knew well; a revelation of how poorly we, with our lifespan of three score years and ten, have risen to the task of making decisions for these gentle giants whose temporal horizon can extend for hundreds and, we have discovered, even thousands of years. Wohlleben documents the importance of community – or forest – to trees, how when they live together they are able to support each other through disease or predation, and shape their environment, including climate, to meet their needs, surviving epochal adversity if left to manage their own destiny. He demonstrates how woefully modern forestry fails trees with plantation monocultures and harvesting methods that destroy the web, setting the forest up for decades of struggle and loss.

Wohlleben – who is unapologetically anthropomorphic (it’s how people communicate, he says, how they will understand the science that underpins his message) – reserves special compassion for lonely trees. The dawn redwood growing by itself in a city park in Europe, short and thick compared to members of its California family, marooned in soil that’s compacted and incapable of channeling oxygen and rainfall to the root zone, deprived of the underground web that would transfer nutrients and information. Or the “street kids,” urban trees going it alone in soil under paving that’s even more compacted than in parks, burned by urine from dogs and salt from the road, dried out by radiated heat, suffocated by exhaust fumes….

Wohlleben details the many ways in which trees plan and budget and prepare for the future, and the many more ways in which we upset their arrangements. Let the trees decide for themselves, he says, how close they should grow together, what mix of species should be allowed. But plantation forests will need time – they aren’t a community. There are no mother trees. “There’s no one there to slow the growth of the little ones, to protect them, or in case of emergency, to feed them sugar.” The first generation of a planted forest will grow too fast and die young, he writes, because the stable structure of a forest is not going to be laid down until much later. It takes 500 years for a disturbed or planted forest to reach equilibrium, he estimates.

Trees have made the world uniquely hospitable for humans and millions of other species. Without trees, life would only be possible in a narrow band around the edge of continents, because clouds, which form over the ocean and release moisture when blown inland, would get rained out after a few hundred miles. But thanks to trees, part of the rainfall is caught in the forest canopy and evaporated immediately to form new clouds which travel further inland to the next forest, and so the process repeats itself. “This water pump works so well that downpours in some areas, like the Amazon basin, are as heavy thousands of miles inland as they are on the coast,” Wohlleben writes. But the coastal forests are the foundation of the process. Without them, it falls apart, “as if you were using an electrical pump to distribute water and you pulled the intake pump out of the pond.”

Maude Barlow describes this in her recently released book Boiling Point: Government Neglect, Corporate Abuse, and Canada’s Water Crisis. “The airborne current, or ‘flying river’ over the Amazon River holds more water than the river itself and carries the water thousands of kilometres to provide rain for thirsty southern Brazil,” she writes. “Or at least it did.” Twenty per cent of the rainforest has been cleared in the past 40 years, and government-sanctioned (let alone illegal) deforestation continues apace. Brazil once received more rain than any other country. Since 2014, its three most populous states have been hit by a severe drought, believed to be due to the drying up of the flying rivers. Just days ago, Bolivia declared a state of emergency because of an extreme drought.

Here in North America, such acute effects may seem remote. Judging by the behaviour of politicians at all levels of government, the prevailing concern is whether protection of forests will interfere with economic activity. Wohlleben does not believe that our new knowledge and the empathy it fosters should mean that trees and forest are off-limits for commercial use. “We are also part of nature and we are made in such a way that we can survive only with the help of organic substances from other species,” he writes. “It is okay to use wood as long as trees are allowed to live in a way that is appropriate to their species. And that means they should be allowed to live to fulfill their social needs, to grow in a true forest environment on undisturbed ground, and to pass their knowledge on to the next generation. And at least some of them should be allowed to grow old with dignity and finally die a natural death.” He has implemented such measures, including harvesting with care using horses, in the forest he manages, and found that “a healthier – perhaps you could even say happier – forest is considerably more productive, and that means it is also more profitable.”

People in different parts of the world are taking note as we relearn our relationship with nature. In Switzerland, since 2000, the constitution requires that “account… is to be taken of the dignity of creation when handling animals, plants and other organisms.” Ecuador’s 2008 constitution is the first to have codified the rights of nature, acknowledging that Nature in all its life forms has the right to exist and flourish, and giving the people the legal authority to enforce these rights on behalf of ecosystems.

The path to recognition of the need to provide such protection takes knowledge and understanding. Wohlleben’s valuable book points the way. Thank goodness – we are all in this together.