Words&Dirt

Naturalists who write for a popular audience have a tough needle to thread. An acceptable work of popular naturalism provides readers with enough detailed research to convey and legitimize the author’s expertise, while simultaneously eschewing esoteric tangents and academic quibbles. A great work will also contain responsible speculation about the borders of human knowledge––just enough to impress and titillate without transgressing into fantasy. Such books can be hard to come by, but Peter Wohlleben’s The Hidden Life of Trees would be at home on any all-star roster; this carefully-observed and accessible journey through Earth’s arboreal realms is nothing short of fantastic.

Wohlleben is a European forester who manages a beech forest in Hümmel, Germany. Although Hidden Life has been available to German readers for a decade now, only last year did the English-speaking world gain access to this slim but ambitious book. Wohlleben’s project is to bring trees to the forefront of humanity’s cultural understanding of nature, offering observations that should affect our decisions at both local and global levels:

I encourage you to look around where you live. What dramas are being played out in wooded areas you can explore? How are commerce and survival balanced in the forests and woodlands you know? This book is a lens to help you take a closer look at what you might have taken for granted. Slow down, breathe deep, and look around. What can you hear? What do you see? How do you feel?

My story also explains why forests matter on a global scale. Trees are important, but when trees unite to create a fully functioning forest, you really can say that the whole is greater than its parts. Your trees may not function exactly as my trees do, and your forest might look a little different, but the underlying narrative is the same: forests matter at a more fundamental level than most of us realize. (x-xi)

This passage exemplifies Wohlleben’s measured and inviting writing style, which is carried through wonderfully by Jane Billinghurst’s able translation from the original German. Readers of all ages and backgrounds will feel at home in these pages, which elicit many of the same soothing effects one might feel on a hike through a peaceful forest. In fact, Hidden Life is perhaps best understood as just that––a guided tour through what we know, and what we might come to know, about the most majestic and impactful members of Earth’s plant communities.

The defining characteristic of Wohlleben’s approach is his unfailing and infectious wonderment. Wohlleben’s experience of forests is heightened by his deep knowledge of how trees interact, survive and thrive. He finds these processes endlessly fascinating, describing such phenomena as familial bonds and friendships between trees, hierarchies in tree communities, and even tree communication, memory, and sensory discernment. Here are some examples:

Four decades ago, scientists noticed something on the African savannah. The giraffes there were feeding on umbrella thorn acacias, and the trees didn’t like this one bit. It took the acacias mere minutes to start pumping toxic substances into their leaves to rid themselves of the large herbivores. The giraffes got the message and moved on to other trees in the vicinity. But did they move on to the trees close by? No, for the time being, they walked right by a few trees and resumed their meal only when they had moved about 100 yards away.

The reason for this behavior is astonishing. The acacia trees that were being eaten gave off a warning gas (specifically, ethylene) that signaled to neighboring trees of the same species that a crisis was at hand. Right away, all the forewarned trees also pumped toxins into their leaves to prepare themselves. (7)

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 trees exchange news about insects, drought, and other dangers. Science has adopted a term first coined by the journal Nature for Dr. Simard’s discovery of the “wood wide web” pervading our forests. What and how much information is exchanged are subjects we have only just begun to research. (10-1)

Small beech trees, which have by now been waiting for at least eighty years, are standing under mother trees that are about two hundred years old––the equivalent of forty-year olds in human terms. The stunted trees can probably expect another two hundred years of twiddling their thumbs before it is finally their turn. The wait time is, however, made bearable. Their mothers are in contact with them through their root systems, and they pass along sugar and other nutrients. You might even say they are nursing their babies. (33-4)

If those passages sent up any red flags for you, that is probably a good thing. One’s enjoyment of Hidden Life comes with an important caveat: readers must be comfortable with a relatively high degree of anthropomorphization. As a reader well-trained in the philosophical language of “Otherness,” this can be a difficult stretch for me. But despite my best efforts, I wasn’t able to resist any of Wohlleben’s central propositions or viewpoints. Perhaps this would be different if I knew more about trees or botany in general, but as far as I can tell, Wohlleben understands perfectly the difficulty of asking an audience to understand nonhuman behavior in human terms. He works dutifully to keep his claims responsible while also questioning scientific definitions that may one day shift permanently:

Right now, the majority of plant researchers are skeptical about whether such behavior points to a repository for intelligence, the faculty of memory, and emotions. Among other things, they get worked up about carrying over findings in similar situations with animals and, at the end of the day, about how this threatens to blur the boundary between plants and animals. And so what? What would be so awful about that? The distinction between plant and animal is, after all, arbitrary and depends on the way an organism feeds itself: the former photosynthesizes and the latter eats other living beings. Finally, the only other big difference is in the amount of time it takes to process information and translate it into action. Does that mean that beings that live in the slow lane are automatically worth less than ones on the fast track? (83-4)

Though Wohlleben clearly loves forests with great passion, he does not irresponsibly romanticize them. Skeptics will be relieved to find this book conspicuously devoid of appeals to nature that might undermine Wohlleben’s credibility. Instead of assuming anything is good simply because it occurs naturally, he instead highlights the concrete and diverse benefits reaped by organisms and communities that live in and near undisturbed old growth forests. Such benefits include climate control, resource sustainability, abundant shelter, biodiversity, as well as access to a environments conducive to scientific inquiry, psychological tranquility, and aesthetic inspiration. Hidden Life also avoids the pitfall of depicting trees as purely peaceful or altruistic stewards of nature. Wohlleben presents forests as complex environments that strike a delicate balance between cooperation and competition. Trees can perhaps be more “friendly” and communitarian than many humans may guess, but they can also be brutal in their struggle to overcome competitors and potential threats.

Wohlleben’s descriptions of “plant-time” are perhaps the most mind-bending of all his offerings: 

The main reason we misunderstand trees…is that they are so incredibly slow. Their childhood and youth last ten times as long as ours. Their complete life-span is at least five times as long as ours. Active movements such as unfurling leaves or growing new shoots take weeks or even months. And so it seems to us that trees are static beings, only slightly more active than rocks. And the sounds that make the forest seem so alive––the rustling of the crowns in the wind, the creaking of branches and trunks as they blow back and forth––are only passive swaying motions that are, at best, a nuisance for the tree. At the same time, some of the processes under the trunk happen much more quickly than the ones we can see. For instance, water and nutrients––that is to say, “tree blood”––flow from the roots up to the leaves at the rate of a third of an inch per second. (230-1)

Such observations are the very best that popular naturalism can offer. They ignite new musings about seemingly mundane aspects of life, infusing our quotidian habits with the capacity for curiosity and exploration. I for one have been spending a lot more time thinking about what the trees on my property and in my community would tell me if I learned how to listen properly.

Hidden Life left me with an urgent, tripartite message. The first component is that it is clearly in humanity’s interest to protect old growth forests and to allow large expanses of previously-disturbed forest to become old once again. The anthro-centric justification is simple: older trees equal better carbon sequestration:

The older the tree, the more quickly it grows. Trees with trunks 3 feet in diameter generated three times as much biomass as trees that were only half as wide. So, in the case of trees, being old doesn’t mean being weak, bowed, and fragile. Quite the opposite, it means being full of energy and highly productive. This means elders are markedly more productive than young whippersnappers, and when it comes to climate change, they are important allies for humans beings…If we want to use forests as a weapon in the fight against climate change, then we must allow them to grow old. (97-8)

While Wohlleben is as strong a tree advocate as you are likely to find, he doesn’t go so far as to claim that we shouldn’t use trees for human consumption. Instead, he champions the much more reasonable position that we should seek to understand the necessary conditions for a forest’s flourishing and seek synergy between human needs and those of trees:

We are made in such a way that we can survive only with the help of organic substances from other species. We share this necessity with all other animals. The real question is whether we help ourselves only to what we need from the forest ecosystem, and––analogous to our treatment of animals––whether we spare the trees unnecessary suffering when we do this.

That means 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 that they should be allowed 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. (242-3)

Fittingly, Wohlleben wraps up by driving home the assertion at the root of Hidden Life’s considerable power. Trees offer an incomparable and indispensable window into the workings of the natural world––one that we (or any intelligent species) would be foolhardy to discount or obliterate:

We shouldn’t be concerned about trees purely for material reasons, we should also care about them because of the little puzzles and wonders they present us with. Under the canopy of the trees, daily dramas and moving love stories are played out. Here is the last remaining piece of Nature, right on our doorstep, where adventures are to be experienced and secrets discovered. And who knows, perhaps one day the language of trees will eventually be deciphered, giving us the raw material for further amazing stories. (245)

If there are still any bright futures available to humanity, this vital perspective is alive and well in all of them.

Rating: 10/10