The Life Arboreal

November 2, 2021   •   By Barbara Kiser

The Arbornaut: A Life Discovering the Eighth Continent in the Trees Above Us

Meg Lowman

A Trillion Trees: How We Can Reforest Our World

Fred Pearce

How I Became a Tree

Sumana Roy

I GREW UP in the company of trees. Northeast of Duluth on the Gunflint Trail, I’d stare into a soughing twilight of massed pines, tamarack, cedar — the boreal forest, Earth’s largest biome. Now, in London, I spend time with a pedunculate oak higher than a house and a grove of hornbeams like dancers frozen in mid-twist. In our doom-scrolling, pandemic-ravaged era, these encounters ground me like little else.

Our affinity for trees is deeply ingrained, of course. Beyond the paleoanthropological theories about our distant branch-swinging ancestors, trees took root early in world culture — myths, ancient sagas, sacred groves — and sprouted in works as various as the Zhuangzi, the Book of Taliesin, John Evelyn’s 1664 treatise Sylva, Mia Couto’s Under the Frangipani, and Toni Morrison’s Beloved. Over past decades, forest ecologists including Suzanne Simard, who in the 1990s discovered the “wood wide web” of mycorrhizal networks, have advanced the science even as writers such as Richard Mabey, Jamaica Kincaid, and Annie Dillard probed the entanglement of trees with the human psyche.

It’s still bosky out there this year. The Heartbeat of Trees, forester Peter Wohlleben’s latest, investigates our charged relationship with the arboreal by way of the human sensorium, the forest pharmacopeia, and sleep behavior in oaks. Simard’s autobiography Finding the Mother Tree is science storytelling that gets to the very root of woodland ecology. And three other books prove how enduring, and protean, our bond with the botanical is.

In How I Became a Tree, Sumana Roy embarks on a subtle cultural and personal experiment: how to “be more tree” in a world increasingly shallow and chaotic. Fred Pearce’s A Trillion Trees distills years of science reportage to lay out research and analysis on forests across more than 40 countries — from their complex ecological benefits to the seesaw of woodland destruction and recovery. As for Meg Lowman’s memoir The Arbornaut, it left me with a startling realization. We reached the Moon a full decade before scientists began to seriously explore treetops — in 1979, when Lowman was one in a handful of researchers making rainforest canopies their living labs.

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Lowman, whose name neatly disproves nominative determinism, has been called “Her Highness” for her pioneering investigations in overstories across the globe. Her four decades aloft, via slings, towers, cherrypickers, hot-air balloons, and aerial walkways, have contributed significantly to forest science and biodiversity mapping. She is much garlanded, but there is nothing of the diva here: Lowman comes across as forthright and engaged, as concerned with supporting fellow scientists and students as she is in parsing the lifespan of a leaf or the snacking habits of a canopy beetle.

Lowman lives and breathes the life scientific, so this is memoir infused with the methodologies of fieldwork, demonstrating process and paraphernalia as she samples, tests, and devises gear for reaching what she calls “the eighth continent.” But the sixtysomething trailblazer has been many things: academic, educator, working parent, conservationist, ranch co-manager, botanical garden CEO. The Arbornaut is an absorbing blow-by-blow account of a seriously packed life.

Self-admittedly shy, Lowman spent hours as a child silently observing nature around her home in Upstate New York, charting forest succession, pressing wildflowers, recording seasonal events from bird migration to canopy leafing like a young Thoreau. In the local Audubon Society, she was “almost the only one under the age of seventy.” At 13, she was teaching dendrology in a wildlife camp. Her grandfather meanwhile built a summer cabin around an American elm — an inspired move, bringing the wild inside. This seems typical of her family. Lacking material wealth, they collectively encouraged Lowman’s inner nerd with rare empathy.

The tension between such drive and dreams, and the slammed doors that can cut them short, is key to the book. Lowman is sensitive to bias because she was so often the only woman in the classroom, boardroom, or canopy. She and her peers bore more than bruises from hitting the glass ceiling; they were “actually major cuts,” she writes. The intolerance began with the male-dominated science faculties of the 1970s. At both Williams College and Duke, Lowman grew increasingly demoralized by both the lack of encouragement and of female mentors even as she avidly absorbed the basics of field biology. After narrowly evading rape while out running on the Duke campus, she had had enough.

Across the Atlantic, pursuing a master’s at the University of Aberdeen, she finally found inclusivity — and terrible weather. Holed up with two equally cash-strapped housemates in a farmhouse as northerlies howled outside, she penned her thesis under an electric blanket, subsisting on cabbage, fish, and the occasional roadkill. She studied phenology in birch in locales from Inverness to Skye, wrangling with the question of whether leafing occurred simultaneously at top and bottom. Up a scaffold, studying the whole tree, she became a fledgling arbornaut. But the “tropical bug” bit, and in 1978 she arrived in Australia on a doctoral fellowship at the University of Sydney — only to confront a dismaying new challenge. The forests she had traveled thousands of miles to study were rapidly disappearing.

With protection some years off, fieldwork was a race against the chainsaw. Although Australia’s rainforests make up just three percent of its forested land, they are biodiversity hotspots housing 60 percent of the country’s plant and butterfly species alone. (Globally, forests harbor an estimated 80 percent of terrestrial species.) Lowman got an inkling of the riches once up in the canopy of her first tropical tree, a towering coachwood (Ceratopetalum apetalum). Using modified caving gear launched via slingshot, she found herself gaping at a tumult of life over 100 feet up. “I could hear the lyrical melodies of crimson rosellas, punctuated by the crack of eastern whipbirds in another treetop, but closer at hand were swarms of buzzing pollinators, colorful beetles crunching…”

Awe — and a well-tested harness — kept her aloft despite hazards such as decaying branches, marsupial tree possums, sweat bees, and barbed vines. She devised a thesis plan to study the lifespan of an evergreen leaf up there in “the most complex salad bar on the planet,” heaving with weevils and leafcutter ants. Little had been written about the canopy, and many of the insects she collected were unknown to science. Her aerial adventures thus contributed to entomology even as her statistical analyses of leaf lifecycles shed light on whole-forest health. Soon, to reduce bias in sampling, she was recruiting teams of citizen scientists and co-designing the world’s first canopy walkway in Queensland to accommodate them.

Post-doctorate, there has been no let up. In the 1990s, Lowman joined botanist Francis Hallé’s Radeau des Cimes expedition, scouring the Cameroonian treetops in a dirigible. She has worked with mobility-limited students studying tardigrades in the canopies of Kansas and, under the JASON project, broadcast virtual expeditions in Central and South America to millions of children. (Talking to seventh graders came in handy with politicians, who “often had about the same level of science training.”)

As a researcher often in the Global South, Lowman makes a point of building relationships with communities, “an asset far more useful than a wheelbarrow full of technical publications.” With local scientists, she has helped to train novice arbornauts while herself gaining insight into how cultural values shape a nation’s forests. In the Western Ghats with ecologists Soubadra Devy and T Ganesh, she saw how India’s embrace of a “whole-forest” approach to field biology and technologies such as camera traps tie in with its traditional conservation of primary forests, many of which have sacred status. In Ethiopia, she has collaborated for over a decade with forest ecologist Alemayehu Wassie Eshete to save the country’s church forests. Island ecologies in dry seas of cultivation, these woodlands cover just 4.2 percent of the land, down from 40 percent 100 years ago. Fired up by this loss, the Coptic priests who look after the forests are building drystone “conservation walls” around them as local children learn about these arks of biodiversity.

A book can be a beacon, a roadmap, an education. The Arbornaut is all that, not least through its demonstration of the “power of one” — the idea that a dedicated individual can seed significant change. But for aspiring scientists, it is also a salutary warning about institutional politics. A 2020 Wellcome Trust survey cited by Lowman found that 60 percent of over 4,000 scientists reported managerial bullying, and she has herself had harrowing experiences with rivalrous bosses. Forced to confront “the world of board dynamics, institutional bullies, and snake-oil fabrications,” she moved on.

Beyond scientists behaving badly, there is a starker warning in The Arbornaut: that mass insect attacks, rampant felling, drought, warming, and fires can bring a forest to the tipping point. Currently, the losses amount to some 25 billion acres a year. Given the centrality of forests to the water cycle, climate, atmosphere, soils, terrestrial biodiversity, and us, the risk at planetary scale is existential. Most ecologists, Lowman admits, missed the climate perspective 30 years ago and now are sprinting to catch up. But today’s researchers must, she stresses, learn “to effectively integrate virtual technology with in situ fieldwork” — get into the woods, not just simulated ecosystems. And fast. She sees Amazon restoration as “unlikely” and notes that the severely depleted primary forests of Madagascar and the Philippines present monumental challenges.

Ultimately, though, she’s less messenger of doom than celebrant of what survives. There’s a crazy moment in this long love letter to the tree. Far up and alone on a walkway in the Amazonian canopy, Lowman watches a storm descend. “With the treetops illuminated by lightning, I felt exhilarated to be soaking wet like all the leaves around me, watching branches dance wildly in the wind.” Sometimes we build context through total immersion. The passion and knowledge to keep Earth habitable can begin with a kid up a maple tree, observing and dreaming.

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More insights, metrics, and cross-continental revelations await in A Trillion Trees, but Fred Pearce trains a science journalist’s lens on the “arborsphere.” The author of over a dozen books on issues from global water supply to the nuclear industry (and once my colleague at New Scientist), he eloquently mulls the ecological dynamics of forests as well as the social, economic, cultural, and political forces that determine their fate. The geographic spread of his reportage is vast, ranging from Ascension Island, Siberia, Sumatra, and the Paraguayan Chaco, to China, Liberia, and Chernobyl.

Like Lowman, Pearce focuses on the importance of conserving old-growth forest and points out the altered state of the rest — noting drily that many “wild” forests are “little more than overgrown gardens.” But on the much-debated issue of tree planting, they differ to a degree. Lowman, while noting that planting seedlings is a “distant second choice” to protecting mature trees, writes approvingly of schemes in India and Ethiopia. Pearce is broadly critical of the model itself, dissecting its ambiguities at some length. Of the several initiatives to plug a trillion more trees into the planet, he writes:

It implies, indeed requires, a global industry, taking over farms and former forest land, often riding roughshod over local rights, in the name of reforestation. If we want a trillion more trees on our planet, as I believe we should, the last thing we need is a big planet-wide project to go out and plant them. […] If we stand back and give them room, forests will regrow.

In this he echoes the British ecologist Oliver Rackham, who observed in his 1986 The History of the Countryside, “tree-planting is not synonymous with conservation; it is an admission that conservation has failed.”

A Trillion Trees is divided into four parts. The first examines recent research on how forests regulate Earth systems. The second probes our felling spree in the service of monoculture and livestock production, which has “pushed the world towards a climatic Armageddon.” The third and fourth look at stories of how forests worldwide “fight back” by effectively reclaiming land, and at the best exemplars of forest stewardship — who are usually not, Pearce notes, Western conservationists.

Alongside discussions of pre-Columbian garden cities and Borneo’s palm-oil “invasion” are compelling findings on the centrality of trees to the hydrological cycle. The researcher Dominick Spracklen has shown how forests make weather, effectively creating their own environment — a “world fit for more trees,” as Pearce puts it. Globally, an estimated 14,000 cubic miles of water a year (around five Lake Superiors) transpire from quintillions of leaves through their pores, or stomata, building clouds and complementing the impact of carbon sequestration by cooling the air. The benefits go far beyond the local, as research on the Amazon’s “flying rivers” has revealed. These airflows convey water from the Atlantic, which is then precipitated and transpired by the rainforest; one of them was found to transport enough water in a day to supply São Paulo for four months. Deforestation, in other words, destroys more than carbon stores and arboreal fauna: it threatens the water security of distant cities and the farms that feed them.

As for who best conserves forests, Pearce confirms what many activists have observed and argued: it is generally the indigenous peoples who live in them. Satellite images of the Amazon graphically show that most relatively untouched areas of forest are managed by tribal groups. For Guyana’s Wapichan or the Warufiji of Tanzania’s River Rufiji Delta, sustainable use is simply tradition. Pearce quotes former UNEP head Klaus Töpfer on the “clear and growing evidence of a link between cultural diversity and biodiversity”; yet even now some environmentalists advise the removal of indigenous peoples from protected land.

Meanwhile, from East Timor to Kenya, local communities ingeniously manage natural regeneration. Pearce relates how in 1980s Niger, two farmers serendipitously discovered that leaving tree stumps in situ and cultivating around them improved soils, water supply, and yields. Across a swath of the country’s south and into Mali, 200 million trees have sprouted under this form of enlightened agroforestry.

It’s through a global mosaic of such good practice (and benign neglect) that a trillion more trees could arise, he asserts. It is happening anyway, as forest succession transforms scrublands around abandoned farms and woodland edges. Meanwhile, the UN Decade on Ecosystem Restoration is now in train to “prevent, halt and reverse the degradation of ecosystems.”

Yet despite Pearce’s depth of analysis, I wonder a little at his optimism. A recent report by Botanic Gardens Conservation International estimates that some 30 percent of the world’s 60,000 tree species are at risk of extinction. And can regrowth really outrun the felling, the galloping climate crisis, and the illiberal governance and industrial greed that exacerbate them? I see it as moot. In an environmental cliffhanger, the uncertainty itself can drive us to find higher ground.

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Ambiguity saturates How I Became a Tree, a memoir and a meditation on the nature and culture of trees that edges into what it means to be human. Sumana Roy, a writer, poet, and academic, has crafted a series of beguiling and at times disorienting thought experiments that draw on psychology, philosophy, literature, myth, and science. As in an archipelago, you sail from the artist Nandalal Bose’s thoughts on drawing twigs to O. Henry’s The Last Leaf, Manuel Lima’s study of branching form in The Book of Trees, and the botanic vision of the poet Rabindranath Tagore.

Roy’s philosophical quest for “arboreality” begins as a rebellion against human speed and noise, the daily avalanche of bad news, the “ambition industry and the violence of professional success.” She finds herself “envying the tree, its disobedience to human time.” Could its rhythms suggest another way of being? As with Daphne, who evades Apollo by turning into a laurel tree, such a transformation might offer escape from “human cruelty.” But perhaps not from the human urge toward utility. Roy cites a character in the ancient Jain text, the Tattvartha Sutra, who is reborn as a shalmali tree and is felled and sawn, over and over. We find both wisdom and terror in forests, she notes; we see them as “both nest and cage.”

The paradoxes wonderfully build. Trees subsist on light but are more at home in nighttime than many women, notes Roy. Trees even generate darkness in daytime by casting shade. Bengali placenames such as Pakurtala (“under the pakur tree”), she writes, are “a whiff of an older history, of a world, in which trees and their ecology of shade were important.” But Roy goes further, seeing the absence of light as concrete and tangible. She ponders whether a tree’s falling shadow could halt in midair, and recalls gathering not mangoes, but the shadows of mangoes, as a child.

Roy skips over the line to human boundary-blurrers, Jagadish Chandra Bose being one of the most fascinating. The Bengali polymath made breakthroughs in radio science and biophysics, and was possessed by the possibility of communication between plants and humans. He invented numerous devices for studying plant physiology, including the crescograph for measuring movement and growth. And he rather beautifully saw the channels through which sap rises as a “diffuse heart.” But biophilia can bend other ways. Sharanya Manivannan’s prose poem “Boyfriend Like a Banyan Tree” plays metaphorically with trees as objects of desire. And in 2015, Roy notes, one Emma McCabe allegedly leapt beyond the figurative by claiming to be in a sexual relationship with a poplar tree, “Tim.”

Like Alice and the looking-glass, Roy is in flight through dissolving barriers. At one point, she even notes a “growing unease with punctuation marks.” It’s amusing, but the forces of constraint she explores and resists are often baleful. In a folktale collected by the poet and translator A. K. Ramanujan, “The Flowering Tree,” a woman magicked into tree form is ravaged and broken. It’s an echo both of the crimes against women in India that Roy touches on, and of the global urge to take axe to wood.

For all its play with the hypothetical, How I Became a Tree asks us to examine our real relationship with trees. “Is the person who goes inside a forest the same as the one coming out of it?” wonders Roy. It’s an ancient idea, the wood as locus of enchantment. If we are indeed in its depths, and find it dark and pathless, what needs to change is, I think, the very way we see and coexist with the forest itself. These books are portals to that transformation.

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Barbara Kiser is a writer and editor based in London, and the former commissioning editor for books and arts at the science journal Nature.