Suzanne Simard has given her life to the study of trees. She sweated for them. Bled for them. Damn near died for them — once at the claws of a grizzly, and once from the invisible clutch of cancer. (Working with toxic herbicides and radioactive isotopes in the course of her research likely contributed to her breast cancer, which resulted in a double mastectomy.) But Simard’s sacrifices as a forest ecologist have paid off. Her work with herbicides uncovered the fact that denuding tree farms doesn’t help them grow faster — a finding that overturned the forestry industry’s prevailing logic for half a century. Later, upending basic Darwinian logic, she showed conclusively that different trees — and even different tree species — are involved in a constant exchange of resources and information via underground fungal networks, known technically as mycorrhizae and popularly as the Wood Wide Web.
Her long fight against the twin patriarchies of the logging industry and the scientific Establishment has yielded startling discoveries about tree sociality — and even, some believe, about tree sentience. Now Simard, a professor at the University of British Columbia, has published a memoir, Finding the Mother Tree: Discovering the Wisdom of the Forest — which is being adapted into a film, with Amy Adams set to star. We spoke recently about what studying trees has taught her about how to live in our increasingly tenuous world, and how forests can help fix our compounding problems.
Do you feel that being a woman in a male-dominated field has given you any special insights into the workings of the plant world?
For sure. I was always on the outside, because it was a man’s world. Women weren’t allowed into forestry until my generation. The whole perspective on forests was all from this one-gendered perspective. It very much focused on competition and dominance. When I came in, saying, “What about the collaborative things going on?” — I don’t think that my male colleagues would have asked those questions. I did learn from them, of course, and they started looking at collaboration too, well before me. But I was the one who took it further and fought the industry.
Your book is full of harrowing stories about your adventures working in the forestry industry, deep in the mountains, being chased by grizzlies and scrambling up trees. But to me, perhaps the scariest thing was the state of forestry back then. What kinds of practices were you witnessing?
I would say that the state of forestry is even worse now. But back then, for me, it was a shock, because I came from a family where we were horse-logging and selective logging, and suddenly I’m working in an industry where it was all clear-cutting and replanting monocultures. I really loved the work, and I try to convey that in the book. I loved being in the old-growth forest, even though I was laying out clear-cuts and roads, because I was so free, and I was doing this dangerous work among grizzlies. But at the same time that I had this love affair with the job, I also saw the devastation that it was wreaking.
You describe how logging companies will fly around in helicopters and spray their clearcuts with Roundup to kill off undergrowth, believing that this will get rid of “competition” and make their tree farms grow faster. But you started to discover that it doesn’t really have the intended effect.
I got a position with Canada’s minister of forests as a research silviculturist, and my job was to research how to regrow these plantations. They had adopted these policies and practices from the U.S., where it was a war on the forest, clear-cutting like crazy and applying multiple layers of herbicides. I did all this research on what the impact of that practice was on different kinds of plant communities. In almost all cases, it made no difference in how fast the trees grew. They grew the same, but the biodiversity was lower. Now, there were some forest types where it did improve growth. But it also caused survival rates to go down, because the trees were getting infected with pathogens and insect infestations. I did this work for like 11 or 12 years, and I published it all, and I’m just going, “The evidence is not there for what we’re doing!” It was making the forest worse. And yet they’ve actually hung onto those policies.
How does it feel, to have your work ignored?
I’m not the only scientist who gets ignored, so that’s okay. These policies get entrenched, and people feel like that policy is their life’s work, so as long as those people are in place, they will protect it to their death. Then, as the policy is in place for longer and longer, there’s a whole industry that evolves around supporting that work — the herbicide industry and the brush-clearing industry and the growing-fast-trees industry. The momentum starts, and once that whole thing gets going, it’s really hard to change.
In the book you describe standing in tree plantations, looking at rows of trees, and a lot of them don’t look healthy. And then you look just off to the side, where there’s a wild forest with a mix of species, and they seem to be doing quite well. It seems like the whole of your career is an investigation of that mystery: Why is it that those trees over there are doing better than the trees on the plantation?
When I started my Ph.D., I learned about this work in the U.K. by David Read, where he had grown pines in root boxes in the lab, and found they connected together; he labeled one pine with carbon-14 and saw it move into another pine. I wanted to find out if that was partly what was going on in my forest. I ended up discovering that the mycorrhizae are really what links the plant with the soil. They were the conduit from the photosynthetic machinery into the soil, which drove everything, all the cycles.
At first people were resistant to the idea that one tree species would be helping another. But that’s precisely what you found.
Yeah, in fact, in that little system that I was working in, with birch, fir, and cedar, the more the birch shaded the fir, the more the birch shared its resources with the fir. That upended our notion that birch was just this competitor; it was actually collaborating. And the system was fluid, so later, when the birch needed resources, the fir would provide it. The upshot of this was that these species coexisted because they found their niche, and they were companions — that biodiversity had a role in not only keeping the forest healthy but also productive.
It seems to fly in the face of a neo-Darwinian, selfish-gene model, but it makes a kind of common sense, the same way you would lend your neighbor a cup of sugar, so that a month down the line they’ll lend one to you. Reciprocity is a basic mechanism of life.
Even Darwin understood collaboration. And now we know, after many decades, starting with Lynn Margulis, who came up with the endosymbiotic theory, that really evolution is a co-evolution. With the microbiome, we know that we are all this kind of consortium of species. But by the time the science got to that point, the practices in agriculture and forestry were really entrenched around trying to manage competition. I think of it as trying to see with only one eye.
If you could have 30 minutes to sit down with Justin Trudeau or Joe Biden and try to change their minds on anything, what would it be?
As a forester, the first thing I would want them to do is to stop cutting down the old forests. In British Columbia, we only have 8 percent of the iconic, productive, old-growth forests left. Eight percent! I always say I grew up in a province of old-growth forests, now I live in a province of clear-cuts. That remaining 8 percent are the hot spots of carbon storage and biodiversity. Let’s just stop. Enough already! And yet we are so enthusiastic to cut them down, ship them overseas as whole logs, and make a few dollars from two-by-fours. We’re just putting the last nails in our own coffin. Of course, that has to go hand in hand with decarbonizing our energy sector, which Biden has already jumped on with feet first, and Justin Trudeau is reluctantly coming along.
In his last State of the Union, Trump pledged to join a campaign to plant 1 trillion trees to mitigate climate change. What do you make of campaigns like that? Will they save the world?
If it’s done correctly, it can do some good. But I’m worried that this is a distraction. Yes, we need to reforest what we have deforested, and we need to restore ecosystems that are degraded. But — I can see it happening already — people are saying, “Oh, we’re going to clear-cut these forests and plant a trillion trees, and that will increase our carbon sequestration capacity.” In the meantime, we’re cutting down these forests which are already storing way more carbon than these little plantations are going to be sequestering. And it’s going to take those plantations decades and decades to catch up to what they were as old forests. So reforestation is a good idea, but only if we keep our old forests intact — keep the boreal intact, keep the Amazon intact, keep our rainforests intact. Because if we lose those, there is no amount of tree planting that is going to save us.
I remember reading that Canada’s forests have now become a net carbon emitter, rather than a carbon sink, due to forest fires. That sent a chill down my spine.
It’s scary. That transition happened in the early 2000s. As climate changes, the forests are more and more stressed, and when fires happen, they’re going to be more extensive and more severe. And of course the velocity of climate change is so fast that the remaining forests are becoming more and more maladapted to their ecosystems, so they’re starting to die back. We are going to need to start helping with that migration, and planting is a great way to do that. I’m also moving genotypes around in the Mother Tree Project — like moving a warmer genotype to a northerly climate — and finding encouraging things.
Tell me a bit about the Mother Tree Project. What is it?
It’s about six years old. We’re looking for alternatives to clear-cutting, because what we found in our basic research on tree connection and communication is that the biggest, oldest trees — what I call the mother trees — are the hubs of these below-ground fungal networks. The idea is, how do we save these mother trees so that they can continue to do these functions? We’re so good at clear-cutting mother trees; we always go for the biggest, oldest trees because they’re so valuable. And I’m saying, “No! We need to do the opposite!” We need to save those trees. And the more trees we can protect around them, the better off they’ll be. We don’t want to just save one, like Big Lonely Doug. It can just blow over in a few years, or they die of shock or drought, which most of them do. The idea is to learn how to manage forests so that they can continue to be resilient as climate changes, and also store a lot of carbon.
When talking to a mass audience — in a TED Talk, or in your book — do you ever feel pressure to go a bit too far out on a limb, emphasizing, say, cooperation over competition, or likening plants’ abilities to our own, in order to elicit wonder? Or do you find that the opposite is true, that when speaking in a scientific context, you’re unable to voice your true beliefs for fear of being regarded as too … woo-woo?
I would say that I’ve evolved over time. It hasn’t been static for me. I got my master’s and Ph.D. at Oregon State University and was trained carefully not to overstep the bounds of my data. I’ve published a lot of journal papers — more than 200. I know the limits. I followed that to a T for most of my career. It’s only been in the last few years that I have really stepped out. It’s because our forests are in deep, deep trouble, and so is our planet. I’m afraid. I’m worried. I have children. I don’t want them to suffer. I needed to make my work better understood. That initial work I did on networks and collaboration, that was done in the early 1990s. And even though it was published in Nature and there was publicity, it didn’t move the needle on forestry practices at all.
At the same time, I started working with more Aboriginal people. I got a postdoc, Teresa Ryan, who is in the Tsimshian Nation, and she was talking to me about how, in the worldview of her nation, everything is connected. And I thought, That’s what we’re missing. Our worldview is wrong. We view the world as this bunch of parts, and we think we can dissect it all and put it back together the way we want and expect it to work. But it doesn’t work. Many Aboriginal people view the trees as their people, just as they view the wolves and the bears and the salmon as their relations. We’ve got to get back to that.
Where do you fall on the question of tree sentience? Do you believe trees have an interior mental life?
There’s a lot of things I don’t know. I don’t know if trees have thoughts. I don’t know if they feel pain. I don’t know if they have emotions. What I can study is the biochemical responses of trees. I know there are structural similarities. I know that even the chemicals that move through mycorrhizal networks are the same chemicals as neurotransmitters in our brain. Somebody said to me once, “It’s like trying to reconstruct your thoughts by looking at a brain scan.” We can’t do that. All I can do is infer that there is an intelligence that is evolved. It has evolved, in a system, in forests.
Do you find that realization has shifted your ethics in any way, in maybe the same way that someone who realizes a cow is intelligent might stop eating beef?
Growing up, I always cared about the environment. I always cared about the shit coming out of the sewer pipes in my town. I always hated to see forests cut down. Even though I worked in the forestry industry, it just ripped me apart. The way my thinking has changed is actually away from Oh my God, we’re going downhill fast and it’s hopeless. Now I understand how these systems work. They’re regenerative systems by nature. When I got cancer, I learned that I was built to heal. I wasn’t built to die. And now I understand that forest ecosystems are the same, with all these networks — they nurture their young, they collaborate, and they compete, too. They have these sophisticated relationships to make the forest resilient. Now I understand that if we put the right things in place, the right policies on the global level and the local level, it can move the needle fairly quickly, once we get going.
A lot of us have been spending more time gardening this year. Have you applied your discoveries to your garden? Do you have any tips for the rest of us?
First of all, you need really good soil. If you have good soil and good compost, you have the foundation of everything. Then you put your plants in and you try to nurture their connections. I started out planting in rows — rows of carrots, rows of peas. But now I’m planting them in clusters, where they have their companion plants around them, where they can make their own networks. And that really follows the Aboriginal people. A lot of First Nations talk about planting gardens like that.
Is it working?
This interview has been edited.