Finding the Mother Tree: How Suzanne Simard changed our understanding of nature

As one of few women in the forestry business, the author becomes a feminist figure and rewrites what we thought we knew about our eco-system all in one memoir, writes Kate Brown

The idea of a cooperative forest and mutual aid is a threatening perspective to some - but not to Simard (Getty)

Trees share. Fast-growing birch send nutrients to slower-moving fir trees. In winter, the goods go in reverse. Birch, shorn of their leaves, receive sugars and carbon from evergreens. Mother trees shoot life-giving nutrients in underground networks of mycorrhizal fungi to saplings circling their crowns. And trees share more than food. They send messages, warnings and defensive chemicals to neighbours. They form mutual aid societies across species. But they don’t collaborate indiscriminately. Mother trees recognise their offspring. A tree standing alone in full sun in a clear-cut forest is not a triumphant conqueror, commanding all resources, but a solitary individual, vulnerable to blight and drought. We know these facts thanks to the work of the forest ecologist Suzanne Simard.

Simard’s memoir, Finding the Mother Tree, describes the intersecting webs of her career and private life that brought her to rewrite not only the forestry canon but our understanding of nature itself. She is an intellectual force whose powerful ideas overshadow her name. Her influence abounds. Simard and her mother trees have starring roles in the 2009 film Avatar. Peter Wohlleben drew on her work in his global bestseller, The Hidden Life of Trees. She was a primary inspiration for a central character in Richard Powers’s Pulitzer Prize-winning novel, The Overstory. Vancouver city planners sought her advice on how to design a city that mimics the connective patterns of northwest forests.

Simard grew up in a family of tree-cutters in western Canada. She understood that communities like hers had to make a living from the forest, and that meant felling trees. She sought initially to figure out why saplings planted after clear-cutting struggled to grow. She watched as tiny fir trees, arranged in rows, yellowed, rusted and withered. Her experiments showed - in opposition to conventional wisdom - that fir trees did better when shaded and crowded by birch and alder.

One of only a few women in the forestry business in northwestern Canada, Simard found that male colleagues ridiculed her work. They understood trees to be in competition with one another for scarce resources. For valuable fir trees to be “free to grow,” wisdom held, competing plants had to be cut, uprooted and poisoned. The great timber yards of the Pacific northwest were (and are) battlefields where foresters deployed weapons of war - tanks retrofitted as bulldozers and chemical weapons refashioned as herbicides — to produce monocrop forests.

When the young Simard presented her research, her male colleagues snickered and heckled. They called her “Miss Birch.” Behind her back, she understood, they changed the last consonants.

Why is the idea of a cooperative forest and mutual aid so threatening? The gendered attack on Simard is telling. She was not the first female scientist to make a case for intricacy and cooperation over individuality and competition. Lynn Margulis was vilified for arguing that microbes taken into cells of plants and animals formed critical symbiotic relationships with their hosts. Barbara McClintock, who discovered “jumping genes,” suggesting that an organism’s genome is dynamic and adaptive, was overlooked for 30 years. Colleagues in Australia refused to speak to Monica Gagliano, now one of the world’s best-known plant researchers, because her experiments showed that plants have memory, intelligence and even consciousness.

Scientists are supposed to be detached. Thankfully, Simard is anything but. To an astonishing extent, her memoir reveals how closely her research calibrates with changing passages in her life

For much of her career, Simard worked from the margins. She drew inspiration from people who had a more expansive view of forests than the commercial value of lumber. She paid attention to Indigenous knowledge. A lightbulb went on when she heard Bruce “Subiyay” Miller of the Skokomish Nation describe the forest as a symbiotic organism. Under the forest floor, Miller taught, “there is an intricate and vast system of roots and fungi that keeps the forest strong.” This intuitively made sense to Simard. She traced the underground fungal connections and quantified Indigenous knowledge, using the methods and language of western science.

Simard organised her work in a way similar to how she describes a well-functioning forest. She sought help from her kin — sister, brother, parents, husband, daughter, nieces and a lifelong best friend, Jean. Theirs was not an easy job. Most of Simard’s experiments took place in “the bush” of western Canada. Simard and her comrades faced hordes of mosquitoes, cold rain, wolves and prowling grizzlies. Some hazards were man-made. To trace the exchange of carbon through soil fungal networks, she gassed saplings with radioactive carbon. Reproducing standard forestry practices, she and her sister, Robyn, doused birch and alder “weeds” with toxic 2,4D and glyphosate. Later, they noticed that their masks lacked filters. She used a neutron source to measure water in soils. One day the housing tube’s locking mechanism failed and the cable did not retract. Body-penetrating neutrons flew around Simard and her sister. Back in the lab, Simard used protective gear while chopping up saplings containing radioactive carbon. Later she realised that her mask had gaps and she may have been breathing in radioactive dust. “How dangerous was this?” she asks in her memoir. That question resonated later when Simard, in her 40s, was diagnosed with an aggressive breast cancer.

Simard’s results are so revolutionary and controversial that they have quickly worked their way into social theory, urban planning, culture and art (Handout)

Scientists are supposed to be detached. Thankfully, Simard is anything but. To an astonishing extent, her memoir reveals how closely her research calibrates with changing passages in her life. She was interested in how saplings of different species exchange nutrients when she was just a sapling herself, struggling to transform childhood friendships into adult relationships. She became engrossed in whether mother trees recognize their offspring in forest networks when she became a mother of two daughters. As she struggled with life-threatening cancer, she grew curious about what dying trees send to neighbour trees in a forest. She discovered that like parents, trees send a parting gift of nutrients as they expire. As soon as Simard overcame her cancer, she started the Mother Tree Project to investigate forest renewal practices that protect biodiversity, carbon storage and regeneration.

Her work is critical to addressing major problems in the timber industry. It is also important for another reason. Humans look to nature to model society. Like Charles Darwin’s findings, Simard’s results are so revolutionary and controversial that they have quickly worked their way into social theory, urban planning, culture and art. Like so many fallen southern generals, Simard’s work knocked 19th-century notions of inevitable competition off their pedestal. If a forest is a commons where the fate of the weakest is tied to that of the strongest, then we have a lot of rethinking to do about the economic and political models that, since Darwin, have been taken to be natural.

Finding the Mother Tree: Discovering the Wisdom of the Forest by Suzanne Simard. Penguin Books, £20.

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