Trees Have Their Own Songs

A new book by David George Haskell invites us to listen.

An oak tree in Estonia (Abrget47j / Wikimedia Commons)

Just as birders can identify birds by their melodious calls, David George Haskell can distinguish trees by their sounds. The task is especially easy when it rains, as it so often does in the Ecuadorian rainforest. Depending on the shapes and sizes of their leaves, the different plants react to falling drops by producing “a splatter of metallic sparks” or “a low, clean, woody thump” or “a speed-typist’s clatter.” Every species has its own song. Train your ears (and abandon the distracting echoes of a plastic rain jacket) and you can carry out a botanical census through sound alone.

“I’ve taught ornithology to students for many years,” says Haskell, a natural history writer and professor of biology at Sewanee. “And I challenge my students: Okay, now that you’ve learned the songs of 100 birds, your task is to learn the sounds of 20 trees. Can you tell an oak from a maple by ear? I have them go out, pour their attention into their ears, and harvest sounds. It’s an almost meditative experience. And from that, you realize that trees sound different, and they have amazing sounds coming from them. Our unaided ears can hear how a maple tree changes its voice as a soft leaves of early spring change into the dying one of autumn.”

This acoustic world is open to everyone, but most of us never enter it. It just seems so counter-intuitive—not to mention a little hokey—to listen to trees. But Haskell does listen, and he describes his experiences with sensuous prose in his enchanting new book The Songs of Trees. A kind of naturalist-poet, Haskell makes a habit of returning to the same places and paying “repeated sensory attention” to them. “I like to sit down and listen, and turn off the apps that come pre-installed in my body,” he says. Humans may be a visual species, but “sounds reveals things that are hidden from our eyes because the vibratory energy of the world comes around barriers and through the ground. Through sound, we come to know the place.”

In his first book, The Forest Unseen, Haskell trekked to the same patch of Tennessee forest and described how a single square meter changed over a year. His keen observations and achingly beautiful narration earned him a spot on the Pulitzer finalist list in 2012. Now, he brings the same sensibility to his sophomore effort. In The Song of Trees, he visits a dozen specially chosen trees, including: a pear tree in the heart of Manhattan; an olive tree in Jerusalem; a sabal palm, roughing the salt and sun of a Georgian beach; a towering, rain-drenched ceibo in Ecuador; and a bonsai pine that survived the Hiroshima bombing and now lives in Washington, D.C. Each of these protagonists is a focal point for stories about the natural world.

But Haskell doesn’t treat the trees as individuals. He sees them as “nature’s great connectors,” living symbols of the book’s great theme—that life is about relationships.

Roots draw nutrients from symbiotic fungi and communicate with neighboring bacteria. Leaves sniff the air to detect the health of neighbors, while releasing alarm chemicals that summon caterpillar-destroying parasites. Seeds are dispersed by far-flying birds. Photosynthetic cells harness the power of sunlight using structures evolved from free-living microbes. And these kinds of relationships are ancient: A balsam fir that Haskell encounters in Ontario exemplifies this idea; it grows on rocks that contain the corpses of bacterial colonies that lived 1.9 to 2.3 billion years ago.

“The fundamental nature of life may be not atomistic but relational,” Haskell says. “Life is not just networked; it is network.”

Haskell sees life, as exemplified by trees, as less about the stories of individuals and more as “temporary aggregations of relationships.” And death, then, is the de-centering of those relationships, as the “self degenerates into the network.” “There’s an ash log here in Tennessee, which is close to where I teach. I had been waiting for years in the forest to be there exactly when a big tree falls, and that particular log blew me away with how many cool creatures came in and used it. It even put out a few buds in the years after it fell. Compared to humans, the difference between life and death seems a lot less clear to me for a tree, and you could argue that its afterlife was more life-giving to the forest than its life.”

A forest’s networks also provide it with something that Haskell likens to intelligence—and he asserts that this isn’t anthropomorphism. Plants sense and respond to their surroundings. They store information—memories—about the threat of grazing mouths or past climatic conditions. They integrate information both within their tissues and beyond. When such processes happen in a nervous system, we talk of minds, thought, and behavior. So it is with plants, Haskell argues.

“I’m very comfortable using words like intelligence, but I need to emphasize that this is a very other kind of intelligence,” he says. It’s slow, diffuse, other. “We’re not putting elves in the forest or imagining one big super-organism that thinks in a human-like way. The forest’s intelligence is so decentralized compared to ours. To me, the closer analogy is of human culture. Ideas and human culture happens between points of consciousness in our brains. It’s very decentralized, but it has memory and contributes to our understanding and our ability to solve problems.”

There is grandeur to this view of life but it also carries a somewhat hippie aesthetic, with its talk of connections, vibratory energy, and in some cases, literal tree-hugging. “My fear is that academic colleagues will read this and think I’ve gone soft-headed,” says Haskell. “A New Age view of the world does capture some truth that relationships are important. But that doesn’t mean nature is a place of endless harmony and loving kindness. Networks are places where that tension between conflict and cooperation get played out. Any field biologist knows that the world is riven by pain as well as beauty.”

“The Victorians had a sugary natural history where divine providence was perceived in the opening of every flower,” he adds. “We’ve now had 100 years of people reacting against that. But in doing so, we’ve overlooked some of the other points about nature—the role of networks, and the importance of symbiosis and cooperation.”

This tendency to focus on individuals at the expense of networks has, Haskell believes, led us to distance ourselves from nature. “I don’t buy either the religious view that we’re separate, or the view from the environmental community that we don’t belong anymore, and the planet would be better off without us,” he says. Seeing nature as an untouched land that we wall off in national parks is, Haskell argues, just as damaging to our sense of belonging as the religious view that we have dominion above all creation. “Dogmas of separation fragment the community of life; they wall humans in a lonely room,” he writes.

We can find salvation in the view of life as a community. In The Song of Trees, Haskell champions a kind of “ecological aesthetics,” where we find beauty in connectivity, and where “the microbial community under our feet may be more richly beautiful than the obvious grandeur of a mountain sunset.” And critically, we are part of those communities—an “insunderable” part of nature’s networks, rather than observers peeking in from the outside. “We can have no deficit of nature; we are nature, even when we are unaware of this nature,” he writes. Becoming aware requires attention and deep engagement, of the kind that most of us rarely pay to our surroundings.

Even Haskell surprises himself. “I go through New York many times a year and a few years ago, I said: I was going to pick a tree,” he tells me. “Talking to New Yorkers, everyone has a tale of triumph or woe about trees on their block or a lack of them. There’s a view that nature isn’t in the city and that is not my experience. So, I wandered around the Upper West Side until I found a tree that would be an interesting interlocutor. It’s very ordinary, which was part of the attraction. It’s a Bradford pear which is regarded as a trash tree.”

He wired it, inserting a sensor into its bark and listening through headphones. “I was hoping for recordings of the sounds of the tree and the subway and the street. But as I was focused on the tree, the whole dynamic of the sidewalk changed.” He became more aware of the people around him, and how his presence—and the tree’s—shaped the flow of the street. “I realized that it’s really about human networks too and it gave me a much deeper appreciation of the importance of trees in an urban context.” Trees can bring us closer to nature, but nature can also bring us closer to each other.

Indeed, Haskell has been pondering matters of unity and divisiveness more and more in recent  months.“This book was written in the years before Trump but we’re in a world where one of the questions before us is: can walls work?” he says. “And I think if we think of the world as fundamentally relational, the question is not how we block things but how we live within those relationships.”