Yyou’ve probably heard the theory that the health of forests depends on common mycorrhizal networks. Trees send resources to their neighbors through strands of hyphae, which act as an underground arboreal postal service, connecting root systems within the soil. Mature trees preferentially provide their offspring with resources, ensuring the survival of their own.
No bells ringing? Try to switch “general mycorrhizal network” with “wood-wide web”, the more familiar term who described this phenomenon in hundreds of more mainstream places: novels, magazines, films and television series. The Wide Web is one of those rare things – a scientific theory that has captured the popular imagination.
The explosion of interest comes not from an irresponsible passion for fungal networks, but for what the theory implies: that the natural world is not static and cruel, but rather a living community governed by the same moral principles as our own.
The concept of the wood-wide web originated in a series of scientific papers led by the forest ecologist Suzanne Simard. Her 2021 book, Find the Mother Tree, cemented the hypothesis as a global phenomenon. No one can blame an academic for framing their work in terms that the layman can understand, even if some precision is lost along the way. But trouble arises when a scientific theory takes on a life of its own, becoming culturally relevant in a way that ignores, simplifies, or contradicts the facts that gave rise to it.
This is what happened in the case of the wide web. In 2023, three scientists, led by Justine Karst at the University of Alberta, created a paper in the journal Nature Ecology & Evolution arguing that the wood-wide web theory has gone too far. Their language was measured: it wasn’t that these mycorrhizal networks didn’t exist, they said, but rather that the claims about what they did outweighed the evidence. More research was needed.
Simard did not take the criticism well. Their paper, she replied, was “an injustice to the whole world”. In a article published in Nature last month she accused Karst of a conflict of interest for taking funding from Canada’s Oil Sands Innovation Alliance – the implication being that her comments were financially rather than scientifically motivated.
Karst then hit back at these allegations, both in the article and later on X. “This was an attack made in bad faith to demean my character and question my objectivity.” she wrote. “Behind the scenes of the ‘debate’ was ugly. It might get worse and I might spend more time defending my character than debating the evidence. I hope you understand that I can only lose in this situation. So, I’m out. Debate without me.”
We think of science as neutral: experiments unfolding neatly, numbers recorded on spreadsheets, society progressing in increments toward an absolute truth. Scientists are the automatons behind this process – temporarily able to transcend the biases, beliefs and subjectivity that make everyday life so complicated for the rest of us.
But that couldn’t be further from the truth. Scientists are not superhuman – they also form attachments. Indeed, in their original article, Karst et al did not blame Simard alone for the runaway success of the wide web. Other scientists also exaggerated the evidence, writing and citing papers in support of the hypothesis, even when the actual papers were lukewarm on the idea. No wonder so many journalists seized on the metaphor: not only was it emotionally appealing, it also rang indisputably true. As a result, the speed at which the idea spread through the public realm outpaced the science underlying the idea itself.
The wide web is one of many cases of scientific ideas gone rogue. I spent the last three years write a book on environmental history – a subject particularly prone to myth and misrepresentation. I usually found that simplicity and romance won out over complexity and nuance. Repetition easily supplanted reality; when enough voices sing in harmony, few stop to question whether the words are true.
One of the many myths I encountered during my research was the Great Forest of Caledon; that is, the idea that the Highlands were once covered in a great pine forest – until people cut it down. Indeed, the central tenets of the myth are often repeat in the media and by politicians.
Contrary to popular belief, however, paleoecological evidence suggests that prehistoric climate change played a major role in the demise of these forests. The reality is more complex and politically less attractive than the oft-repeated myth. But we must not fear difficult ideas.
I like simplicity and romance, but I also like accuracy and open-minded debate. Scotland has fewer pine forests than it could; the past doesn’t change that. Meanwhile, scientists continue to work quietly to unravel the many mysteries of mycorrhizae. How widespread are these networks in forests? Do they really benefit seedlings? Can mature trees really support their family? Let’s hope the web is flexible enough to incorporate such progress as it happens. As Karst put it himself: “Less hype. More hyphae.”
Science thrives on debate. When people become wedded to a particular idea, that debate can become personal. Opponents are no longer challenging a hypothesis, but a worldview, one to which many people outside of science have become attached. We owe it to the planet – and to each other – to remain open to the truth.
