The idea is captivating enough to have mesmerised the public, Hollywood, and even esteemed institutions: trees supposedly communicate through a hidden network. But scientists are now debunking this concept, claiming it lacks evidence and poses risks to forest ecosystems.
"The collective hysteria around this topic is exhausting," says biologist Pierre-Henri Gouyon of the National Museum of Natural History in Paris.
Image courtesy: Epsiloon
How It All Began
In 1997, Suzanne Simard and her team from the University of British Columbia published groundbreaking research showing a 6% underground resource exchange between a birch and a Douglas fir. The discovery, hailed by Nature, introduced the idea of the "Wood Wide Web" to the scientific and public imagination.
The concept—a subterranean network facilitating resource and information sharing—was electrifying. It inspired books like Peter Wohlleben’s The Hidden Life of Trees (2015), which depicted fungi filaments as bridges connecting trees, transmitting nutrients and even danger alerts. Translated into over 40 languages, it became a bestseller.
In 2021, Simard expanded on these ideas in her memoirs, describing forests as nurturing communities led by "mother trees" communicating with saplings via fungal networks. Hollywood embraced the narrative: James Cameron borrowed it for Avatar, while Amy Adams and Jake Gyllenhaal acquired rights to adapt Simard's book for the screen.
The Science Unravels
Despite its popular appeal, many scientists now challenge the validity of the Wood Wide Web theory. "Extraordinary claims require extraordinary evidence," asserts forest ecologist Torgny Näsholm from Sweden’s University of Agricultural Sciences. But compelling evidence remains elusive.
It’s well-documented that trees engage in mutualistic relationships with fungi, sharing root systems with 100–200 fungal species. Trees allocate 30–70% of photosynthesised carbon to underground networks, forming a "collective snack" for surrounding organisms. However, studies fail to prove direct tree-to-tree nutrient exchange through fungal networks, let alone communication of danger signals or memory.
A 2024 literature review led by ecologist Justine Karst (University of Alberta) revealed that among 28 field experiments, only five suggested potential nutrient transfer between trees. None demonstrated a tangible impact on seedling performance. Earlier research by Simard’s former student, Brian Pickles, found that carbon transfer between trees amounted to less than 1%, a negligible amount nutritionally.
The Competition Narrative
Historical studies further challenge the notion of a cooperative forest. As early as 1926, Finnish research documented competition rather than collaboration among Scandinavian pines. Nearby young trees showed stunted growth due to resource rivalry. Modern studies corroborate this, finding mature trees often outcompete seedlings for nitrogen and other nutrients.
"The idea of self-sacrificing trees supporting others for the good of the community is a misconception," says plant biologist Kathryn Flinn from Baldwin Wallace University. In reality, trees compete for sunlight, nutrients, and water, with natural selection favouring those that maximise their resources.
Public and Policy Impact
While some scientists admire how Wohlleben and Simard’s narratives have rekindled public interest in forests, others criticise their selective use of evidence. "This theory may justify inaction at a time when forests face unprecedented threats from climate change and diseases," warns forest manager Ethan Tapper.
The myth’s influence extends into policymaking. A 2022 European Parliament report on sustainable forestry adopted the concept of tree communication via fungal networks, prompting calls for forest management to align with the Wood Wide Web theory. Critics fear such approaches could lead to poor outcomes, such as stagnation in managed forests, reduced biodiversity, and increased vulnerability to climate stress.
A Beautiful Myth, But at What Cost?
While the Wood Wide Web myth has fostered empathy for forests, its scientific basis is fragile. Misguided beliefs could harm ecosystems by promoting passive conservation strategies where active management is necessary. As forest ecologist Lincoln Taiz cautions, "We shouldn’t base practices on inconclusive research."
The myth’s allure poses a dilemma: does its potential to inspire forest protection outweigh the risk of spreading misinformation? As the scientific consensus veers towards scepticism, the debate continues to divide researchers, policymakers, and forest managers.