The best books on Trees

What do we need to understand about trees?

Let’s bend time and space, travelling to our species’ origin in Africa: Our (very-)great-grandparents sit at a campfire, roasting meat and roots. They relax at the sound of crackling wood and their conversation turns from the everyday to the realm of the imagination. Human culture is born, catalyzed by burning tree branches. To this day, wood fires change the texture of the human mind, pivoting us into a place of social connection and creativity. This happens even in the lab, with only the recorded sound of a campfire.

Back at the ancient campfire, food is cooked – and nutrients released – by the sudden release of sunlight trapped inside the burning tree branches. Our big human brains and delicate teeth evolved because wood made cooking possible. Other major technological and cultural advances also happened through our relationship with trees: shelter, shafted tools, musical instruments, paper. These connections continue to this day and are industrialized and magnified in wood- and fossil-wood-burning factories, clean drinking water piped into cities from forests, oxygenated air bathing our lungs, and CO2 sponged from the atmosphere by forests.

“Extended attention to the seemingly small and insignificant paradoxically takes us into the bigger questions”

Our modern dependence on trees is mostly hidden from our senses. We don’t hear the rain passing through forest canopies on its way to the reservoir. We don’t smell the wood pellets and coal chunks that power our computers and homes. The wood that frames our houses, holds up our furniture, and gives us paper arrives with signs of its ecological history purged. So we imagine that we’ve transcended our ancestors’ close relationship with trees. But this is illusion. There is no good future for Homo sapiens without forests.

Yet forests are in crisis. We live in an age of great diminishment. In just the first dozen years of this millennium, 2.3 million square kilometres of forest were lost – cut, burned, drowned, desertified – yet only 0.8 million regrew or were replanted.

You have written two books for the general reader about forests and trees: The Forest Unseen: A Year’s Watch in Nature (2012) and The Songs of Trees: Stories of Nature’s Great Connectors (2017). The first focuses on a square metre of ground on a mountainside in Tennessee. The second ranges across the world in time and space. What unites them and distinguishes them from each other?

Sit down. Shut up. Pay attention. Repeat, hundreds of times over.

That’s the method that unites the books. Through attention to what seem to be small places, I try to open my senses and break through my preconceptions. I then scurry off to the library to burrow into the scientific literature and seek the ideas that might explain what I’ve experienced in the forest or with a tree.

So in both books I weave my open-sensed experience with larger ideas about ecology, evolution, and human culture. But this is an imperfect description because “weave” implies that these are separate strands. In my experience, “universal” ideas (natural selection, ethics, the cycles of ecology) are all present within the particular. So extended attention to the seemingly small and insignificant paradoxically takes us into the bigger questions. Contemplatives in religious traditions have known this for millennia and have developed meditation practices to cultivate such insight. Most fiction uses a similar approach: an intense focus on a small number of characters touches deeper than a panoramic survey of thousands of people. The study of natural history also has a long tradition of attention to place, now partly engulfed and destroyed by an education system that deracinates us.

“The book’s central argument is that you cannot understand human evolution and our future without also understanding trees”

My two books differ most obviously in their geographic scope. One keeps its gaze on a single patch of old-growth forest, the other moves among a dozen trees around the world. But the more profound difference is the role of people in each book. The Forest Unseen is set in a forest where people are visitors and have important but indirect effects. The trees in the second book are, in contrast, located right on the front lines of environmental change, urbanization, industrial development, and human conflict. Some have been bombed, others planted, and all live in deep connection to people. So The Songs of Trees is as much about people as it is about trees. Indeed, the book’s central argument is that you cannot understand human evolution and our future without also understanding trees.

Turning to the books you’re recommending, your first choice is Ecology of a Cracker Childhood (1999) by Janisse Ray. What makes this book so remarkable?

Janisse Ray tells the story of one of the world’s great forests—the longleaf of the southeastern US, an ecosystem mostly obliterated in the 19th century—through her experience of being “raised in a junkyard”, in a region most people now write off as being “as ugly as a place can get”. Her book tells this story from the perspectives of those often missing from writing about forests and trees: a child, a young woman, a daughter of a fundamentalist, a poor family with poorer neighbours, and a culture that has lived within the forest and its ecologically degraded remnants for generations. Ray is a vital, insightful writer and her voice is full of the language and modes of thought of what she calls her “homeland” of “lost forests”. In telling her stories, she unfolds the many cultural, ecological, ethical and personal layers of our relationships to trees and ecological communities.

Ray may have grown up in a junkyard, but the childhood she describes back in the 1960s and 70s was one in which she was able to get out into the woods.  I tend to assume that—as in many other places—many if not most children in the southeast US today grow up in more material comfort but with less direct contact with the natural world than Ray. Still, many of us like to think that we’re more environmentally aware and ecologically literate than previous generations. But is that really the case? After all, there is much concern about shorter attention spans in a hyper-connected world. What is your experience, as a teacher and researcher?

The world has always been biologically hyper-connected: every living body, every forest, every drop of ocean water is a swarm of connections. Our electronic media are the latest manifestation of life’s networks, an outgrowth of the social nature of the human mind. The medium is new, but the problems are old. Every network faces a tension between openness and walls, opportunity and vulnerability. And so the arms race that we’re all suffering through now in electronic media is a variation on an ancient theme. It manifests in the present day as a battle between those who would grab our attention and our ability to control our own time. But the tension is this: how do I belong to this network without completely losing all agency within it? This is the same problem that tree roots face as they negotiate with fungal partners below ground, that microbes face in their chemical connections in the ocean, that our gut cells struggle with as they work with bacteria. There is no way out of this tension. We cannot live in complete openness or behind high walls. So we must engage and discern how to live within the network.

What I experience in my own life and in my work with students is that we’re often unconscious of just how vigorous the assaults on our attention have become. So, yes, we have shorter attention spans because we’re being invaded by the pathology of mind-grabbing micro-media. But we’re counter-evolving. I encounter a great hunger in my students to restore more control, more balance, so that we’re the ones choosing how our minutes, days, and lives will pass, not giving up that control to the algorithms of manipulation. Smelling the soil, talking to other people, holding an acorn in your hand, coming to know the sounds of birds and trees: these have great power once we wake to them, partly because they are such multi-sensory activities, engaging mind and emotion.

As for the decline in contact with the “natural world”, I’d argue that a computer screen is just as natural as a mountain stream. It has more of the human mind present within its development, but that mind is natural. So I’d prefer to talk about the decline in awakened contact with “the other”, with other species, other people. And for many, yes, our connection to other species is diminished in some ways. But in other ways there is more “environmental” education and awareness now than decades ago. And the direction of this trend differs depending on class and race. For working class people in urban or industrial landscapes, the opportunities for contact with green space are much expanded, at least here in the US. The upper classes and those who grew up in the countryside see their kids and grandkids losing out on the unleashed experience of play and exploration in woods and fields. In many cities, that opportunity is now expanded, not contracted.

“Our big human brains and delicate teeth evolved because wood made cooking possible. Other major technological and cultural advances also happened in relationship with trees: shelter, shafted tools, musical instruments, paper”

In the case of the rural southeastern US where Ray is writing, contact with the ecological community was, for generations, forced on people by slavery, share-cropping and poverty. That legacy is well remembered in some families. People left the fields and woods for a reason, and have little interest in a return, especially one mediated by the well-meaning wealthy white descendants of the land-owning classes. This is not true in regions away from the southeast US, but race and class deserve more attention as we discuss “nature”.

In Ray’s case I believe that the most important arc of her book is her exploration of what it means to grow up in ecological ignorance, to awaken to the extraordinary stories of her home, then to face the devastating knowledge that most of the ecological vitality of the region is gone, partly at the hands of one’s own ancestors and partly by economic forces that don’t give a damn about trees or people. It would be easy to paint a simple arc, but she resists this and shows us, indirectly through familial stories, how complex this process is. She connects history, religion, gender, economics, and ecology. Yes, she grew up with lots of outdoor time, but she also grew up with little understanding of where she was and what the place had been. This is a loss, only partly redeemable by later knowledge. In her awakening – one we all go through as we learn how diminished and wounded our homes and planet have become – she walks us through grief, anger, wonder, puzzlement, regret. Her writing does this without leaving us with an easy conclusion. Instead we get a fiery dream for the future.

That future is one where the longleaf pine forest might be restored. This forest once covered 90 million acres — about the same area as the UK and Ireland combined. The pines grew to great sizes, widely spaced in meadows kept open by regular fire. Plant diversity in the meadows was phenomenal. Now, only about 12,000 acres remain. The rest went to timber and turpentine, then was converted to monoculture tree farms and agricultural fields. Most of the loss happened in a few decades of the mid-late nineteenth century, a startlingly rapid loss. Of course, many of the plants and animals of the forest are now gone or critically endangered.

In some areas the forest in being restored. But these hopeful signs should not blind us to the fact that, over much of the rural southeast, the pattern of ecological abuse of the land continues. In an article last year about a coal ash dump near her home, Ray wrote: “We are suffering out here in rural America. We are watching agrarian landscapes turned into industrial ones (giant clear-cuts, giant glyphosated fields, giant genetically engineered eucalyptus plantations), and we are watching the high quality of rural life, with its hummingbirds and purple martins, its trilliums and turnips, its streams and lakes, made toxic.” One reason The Ecology of a Cracker Childhood is so important is that the injustices and violence that she describes are still underway. The study of trees is not an escape into a natural wonderland, rather it’s a way to see what is beautiful and what is broken in the world, to try to find a way forward.

This point is central to many of the trees you visit in The Songs of Trees, including a giant ceibo in the Yasuni Biosphere reserve in Ecuador, though I must say your account left me feeling intensely anxious about its future.

Yes, this ceibo tree in the Amazon rainforest grows in the most biodiverse place on the face of the planet, a forest that is also home to several indigenous cultures, people who have lived there for thousands of years. All this is threatened by extraction of oil deposits under the forest. From the top of the ceibo tree I saw forest stretching to the horizon, but I could also hear generators and drills working in the forest.

Once roads and industry move into the Amazon, the forest’s diversity unravels and local peoples are displaced. Great biotic diminishment and human injustice are underway and will continue if oil extraction intensifies. But political and legal action within Ecuador offer hope that this battle is not lost. The country changed its constitution to give rights to “nature” and there is strong public support for protection of the Amazon. One indigenous activist told me, “Our politics is this: to show that trees and rivers have music, songs, and life…[to live] with the millions of beings in the forest.” That future is threatened, but still possible.

Your second choice is the Handbook of Nature Study by Anna Botsford Comstock. The first edition appeared in 1911 and was intended for primary school teachers. It reads like something from a gentler age, or at least the illusion of one.

Gentler in literary tone, but not in lived experience. In the US at the time, infant mortality rates were close to 10% for the first year of life and nearly 1% of births killed the mother. TB was endemic. So people understood that “nature” was, as Tennyson put it, “careless of the single life”, often quite dark.

Comstock’s book is important because she changed the course of education in the US, making the case for what we’d now call “environmental education” both through her writing and her advocacy for educational reform. She justified this work to her readers and funders (in agriculture schools) by noting that increased urbanization was drawing people away from relationship with the land. Alongside her instruction about particulars was an imperative to teachers and students: be curious, open your mind and senses to the many lives of other species around you.

“Contact with the ecological community was, for generations, forced on people by slavery, share-cropping and poverty… Race and class deserve more attention as we discuss ‘nature’”

Comstock writes with great precision of observation and respect for science while using personification of her subjects as a narrative technique. It’s hard to pull this off successfully. To modern ears her work is dated, especially on matters of gender and race, but, like Jean-Henri Fabre, she set the bar high for subsequent writers. To this day, there’s a temptation to either jump so far into anthropomorphism that we lose sight of the actual lives of the creatures we’re studying, or to erect walls of objectivity that deny our bodily and emotional kinship with other species.

Anthropomorphism—or at least the description of trees in terms we normally apply to human or animal life— is something you’ve also engaged in. In The Songs of Trees you write that a “forest throbs with the water-blood heartbeat of twigs…On sun-happy branches, systole and diastole surge and draw back, the forest’s subsonic hum.” 

Twigs appear static, literally “wooden”. But they’re dynamic, wood is a lively substance. Growing twigs have a pulsing 24-hour rhythm, narrowing during the day as water moves through them, then swelling at night. I use the metaphor of our own heart and arteries to draw the reader’s imagination into this odd property of twigs. I hope that familiar words from the world of humans are a bridge to understanding the unexpected, sometimes strange world of plant life. The metaphor works only if it helps us understand the life of the plant, in this case the slow and — for our ears and eyes — unseen, unheard pulsing that surrounds us in the forest.

Your third book is The New Sylva by Gabriel Hemery and Sarah Simblet. It’s a very British book and, though published in 2014, alludes to a work of 1664.

I chose this book first and foremost for Sarah Simblet’s spectacular ink drawings. Trees live at scales that are hard to represent. Their form is much larger than we readily apprehend with senses tuned to human scale (torso size, which is why bonsai is such an effective artform). But they’re also made of detail — bud scales, texture of twig bark, leaf edging — that is so small that our senses often skip over it. Simblet’s drawings speak very powerfully of the nature of each of her subjects. Through her work I understand and sense the trees, a very direct and profound experience. This comes across in the book plates and even more so in the originals that I saw at the Royal Botanic Gardens in Edinburgh. I learned afterward from her “note” in the book that she draws with a single steel-dip pen, often while holding the plant in her other hand. I suspect that this method allows deeper sensory understanding, more expansive observation. The use of a single pen is perhaps analogous to meditative technique, going deeper through material focus and simplicity.

The very first book published by The Royal Society was John Evelyn’s Sylva. This most august of scientific societies understood at its origin that human lives and tree lives were deeply interconnected. As you mention, The New Sylva is a response and homage — an attempt to underscore this truth for the present day. And just as Sarah Simblet connects detail with broader understanding, Gabriel Hemery’s text gathers many particulars — especially practical wisdom gained through horticulture in British soil — to make a larger argument that our well-being depends on trees. In the seventeenth century this dependence was obvious through everyday use of timber and fuel wood. It was also a matter of national security as the navy needed oak for its warships. Today the connections are just as vital, but indirect and often global in scale. Hemery also outlines threats to trees, especially climate change and invasive pests. These two factors will fell more trees than the navy ever did and combatting them should be high on the agenda of any country. This is partly what I’ve tried to do in The Songs of Trees: bring these unexpected stories of interconnection into the light.

Your fourth choice is David Hinton’s translation of Inner Chapters, a classic text of Taoism attributed to  Chuang Tzu, or Zhuangzi as he is known in pinyin. What does this have to do with trees?

Trees are not symbols or allegories in this foundational Taoist text. Rather, they’re examples of the true nature of life. Chuang Tzu’s Inner Chapters present a refreshingly ecological philosophy. In Chuang Tzu, the Earth is a “mighty mudball”, time is measured by the life-spans of ancient trees and ephemeral mushrooms, and human perception emerges from the quirks of our physiology and ecology.

All human philosophies are natural productions, but many philosophies paradoxically deny this. Our thoughts emerge like tree trunks and branches from roots in our nervous systems, so they’re just as wild and natural as any tree, bird, or bacterium. Yet these very thoughts imagine a separation from the rest of the community of life, a fracture caused by gods or by the sophistication of our culture, mind, and technology. Chuang Tzu punctures this inflated view using wit, paradox, irony, and exposition. He transmutes human exceptionalism into a humbler view, one informed by kinship and belonging on this Earth. Trees appear at pivotal moments in his stories, places where he makes clear that humans are of the earth.

Other traditions of course also have trees at the centre of their narratives — the Tree of the Knowledge of Good and Evil, The Bodhi tree under which Buddha was enlightened, the Norse Yggdrasil, the creation trees of the Amazon, even the evolutionary tree of Darwinian genealogy – a near-universal recognition of the importance of trees to our lives. Chuang Tzu seems to me to go deeper, actually listening to trees rather than using them only as symbols and narrative devices.

Listening is central to your project in The Songs of Trees.

Yes, I visited a dozen trees around the world to listen to their stories. By “listening” I mean literally tuning my ears (and some electronic sensors) to trees to hear their many sounds. I also mean listening to people whose lives are connected to each tree and scientists who have studied the lives of trees.

“Sound is a great way into tree lives: it passes around and through solid barriers, revealing what our eyes cannot see”

I found that trees are full of sound. Wind reveals the architecture of branches and leaves, and every tree has its own wind sound, emerging from the particularities of its physiology. For example, the Ponderosa pine trees in Colorado sound different from the same species in California. Each has needles adapted to the local environment, so each sounds different when the wind blows. Broad-leaves trees are likewise diverse in their voices. City trees have rumbles of buses and trains running through them, changing the form of their wood. Birds sing from branches and insects gnaw on inner wood. Then there are tree sounds that are too high for our ears, but by listening with sensitive microphones I heard water pulsing through branches and ultrasonic clicks of distress in drought-stricken twigs. These sounds combined with the voices of market vendors working in the trees’ shade, birds singing amid traffic noise, and surf sucking at palm roots on an eroding beach. Sound is a great way into tree lives: it passes around and through solid barriers, revealing what our eyes cannot see.

Your final choice is The Botany of Desire: A Plant’s-eye View of the World (2001) by Michael Pollan. It’s been a while since I read this, but what I chiefly recall is his account of Johnny Appleseed, who in the early 19th century introduced apple trees across five or six American states. Why do you recommend this book? 

Pollan gives us a witty insight into a plant-centered view of evolution and ecology, flipping the usual human-focused narrative of the interaction between people and plants. Through the stories of four familiar plant species – apples, tulips, marijuana, and potatoes – he demolishes the “erroneous impression that we’re in charge”. We did not “domesticate” these species. Rather, the plants’ evolutionary nimbleness allowed them to insinuate themselves into human desire and so thrive. Human minds, emotions, and tastes are part of the environment to which plants adapt. Like bees guided to the work of pollination by petals and nectar, we’ve been willing and industrious servants of some plants’ needs.

Pollan’s account of the reciprocal web of relationships among plants and people takes our understanding of coevolution out of the specialized world of evolutionary theorists and into our everyday experience of orchard, forest, garden, and kitchen. In learning how apples spread from Kazakhstan, we understand how the fates of people and plants are conjoined across the world. In the interplay between plant evolution and human desire we see the future of forests: Humans have become world-changing bees. Plant evolution in the future will be largely a matter of adapting to and exploiting – or not, for many species – the proclivities of a hyper-abundant Great Ape.