When should we encourage stories that make us fall in love with the forest and when should we stick to tested, proven science?
This is the debate unfolding between scientists as they explore what's happening beneath the surface of the forest.
You may have heard of the “wood wide web,” a term coined in 1997 to explain B.C. scientist Suzanne Simard’s work exploring the complex ways in which trees and mushrooms communicate and share resources.
The term was created by Simard’s editors at the journal Nature in 1997 when she published her first paper. This was around the same time that the world wide web, now better known as the internet, was taking off.
The "wood wide web" has become a bit of a media darling since then.
Forbes encourages people to network like trees; Playmobil tweets about it to celebrate tree day; the CBC (and The Tyee) have reported on it; the concept shows up in the relaunched Magic School Bus; in kids books; and even in the New York Times crossword.
Somewhat unsurprisingly — debate is a regular part of the scientific process — scientists today are duelling over exactly what we can say for certain about the "wood wide web." On one side there are those who cheer on the concept and how it encourages us to engage with forests. On the other, a collection of more cautious scientists worry the idea has grown beyond what’s been shown by research.
On the first side is Simard and the numerous papers she’s published in highly esteemed academic journals, which analyze and explain how plants and mushrooms communicate and share resources.
Although she didn’t coin the phrase, the concept of the "wood wide web" is likely Simard’s most well-known work. In an overview of her research, Simard says her work shows that fungal networks help trees trade carbon, water and nutrients “with a topology similar to that of neural networks, stream networks in watersheds and the internet.” Simard is also well-known for her concept of the Mother Tree, a large, healthy elder in the forest who takes on extra work making and then distributing resources throughout the forest using the "wood wide web."
German forester and author Peter Wohlleben is also in this camp. While he doesn’t have an academic or scientific background, his books exploring the concept are incredibly popular around the world.
Camp Web advocates for the public to grab hold of the “wood wide web” for twin purposes: to find wonder in forests and to call for a change in destructive forestry practices.
Most of B.C.’s forests are logged using a clear-cut strategy and replanted with monoculture seedlings to ensure the crop can be harvested again in 100-odd years. Camp web would like to see more Mother Trees left on a cutblock and, in his latest book, The Power of Trees, Wohlleben suggests replanting a cut block should also be avoided, instead allowing a forest to grow back on its own.
“People take this concept and they create songs, symphonies, plays and art,” Simard told The Tyee, adding that it should be permissible for the public to be fuelled and inspired by what they take from her research.
Wohlleben agrees. Speaking over Zoom from his home in Germany, he says “when it comes to environmental protection we’ll need more than scientists to protect it.” He adds his books cite a lot of research and in them he often adds disclaimers around what his views are versus his research on forest science. This is also a world of research that is rapidly evolving, he adds.
Simard says her work suggests loggers should leave tall, old-growth forests alone. She compares that to the status-quo research which she says has helped loggers cut down all old growth in the province until there’s only two to three per cent left.
Camp more research
On the other side are scientists who say the science behind the idea of the "wood wide web" needs more research — a lot more — and that the idea of an interconnected forest communicating and sharing resources might not exist in the way that the public seems to think it does.
Both papers find the research supporting the existence of a “wood wide web” is “lacking” and call for further studies to better understand what’s happening beneath the forest floor.
The Canadian review was published in the “perspective” section of the Nature Ecology & Evolution journal, and the Swedish review in the “viewpoints” section of the New Phytologist journal. The “perspectives” section is where articles get published that “do not meet the criteria for a review — either because the scope is too narrow, or because the author is advocating a controversial position or a speculative hypothesis or discussing work primarily from one group,” and “viewpoints” “provide a bridge between a research article and a review,” according to the respective journals’ publishing guidelines.
Neither paper denies there is some form of interaction happening between plants and mushrooms underground. But they do question to what extent these interactions are happening, and what they're doing for the different life forms.
The Canadian review paper looked at how accurately researchers cited studies done on common mycorrhizal networks. It looked at 1,676 citations and found one quarter of them got something wrong about the structure of the network and 50 per cent got something wrong about the function of the network.
Justine Karst, co-author of the Canadian paper and associate professor in the department of renewable resources at the University of Alberta, told The Tyee the idea of a “wood wide web” is “problematic” because of its disconnect with the research that has so-far been done on the topic.
“I’d like to see more old-growth forests protected but this ‘wood wide web’ distorts the evidence,” she says. “If someone was saying we should cut down all the forests I’d be asking the same questions.”
“We didn’t come at the review to try and debunk the claims,” Karst says. “We thought we must be missing something, so we did a deep dive in the literature.”
“We need to keep the public trust in science,” Karst says.
An outside perspective
Tom Kimmerer, a consulting forest ecologist with 40-odd years in the industry and a PhD in forestry, plant physiology and chemistry, praises Simard as a “good scientist” with “credible” research.
But he notes that her original concept of a “wood wide web” might not turn out to be what we originally thought. That’s OK, he adds — science is all about testing an idea and then seeing if you can get the same results again or discover something else along the way.
“The concept of the ‘wood wide web’ is a very good one,” he continues. “It’s turning out that further experimentation says it doesn’t work the way it was originally proposed to work. We might not even call it that anymore. But doing further experimentation is leading us to a much deeper understanding of all of the interactions that go on below ground.”
Simard says further experimentation is complicated, expensive and time-consuming — she’s had experiments take more than five years — and difficult to replicate from place to place because each forest is its own completely different ecosystem.
It’s also a complex topic, Kimmerer says. A tablespoon of soil can have a billion microbes which all interact uniquely with one another; a single tree can have 7,000 different fungal relationships.
Then there’s the challenge of how best to share scientific work with the general public.
Kimmerer says scientists are used to their research being misinterpreted. But explaining complex ideas in simple terms is still possible, he says, adding he regularly teaches third-graders about forest science.
This should be done without anthropomorphizing non-human life forms, he says.
“I don’t think it’s good for us to pretend the natural world works like we do,” he adds. “It’s more complicated than we know and more beautiful.”
“We should be trying to understand what they are rather than making up humanized stories about them,” he says, referring to the microbes in soil as an example.
Wohlleben disagrees. The human brain will always be limited to thinking in terms it already knows and will only ever be able to think like a human, he says, so it’s fine to use terms related to humans.
Both Karst and Kimmerer take issue with Wohlleben’s writing style; Kimmerer warns it “cherry picks” forest science.
Simard says when she first read his 2015 book The Hidden Life of Trees, she felt he’d “gone too far.”
But then she changed her mind when she noticed how his writing made people notice the forest for the trees.
“He made people think that forests are valuable,” she says. “That service is much greater than any harm he could have done.”
So does a "wood wide web" exist? Maybe, and scientists are still busily trying to find out how it works and to what extent it connects living things in a forest.
One thing all sides agree on: more research is needed, and they’re itching to dive in.