Walk into an old-growth forest and the silence can feel absolute. There is no visible movement beneath your feet, nothing to suggest that anything is happening underground. But beneath that quiet surface lies one of the most active communication systems on Earth: a vast, living network of fungal threads connecting tree to tree, sharing carbon, water, and warning signals across distances that would take you hours to walk.
Scientists call it the mycorrhizal network. Journalists, more evocatively, call it the Wood Wide Web. Both names point to the same discovery, one that has quietly reshaped how ecologists think about forests, not as collections of individual, competing trees, but as something closer to a single interconnected organism.
What a Mycorrhizal Network Actually Is
The word mycorrhiza comes from the Greek mykes (fungus) and rhiza (root), and it describes a symbiotic relationship in which fungal filaments, called hyphae, colonize a plant's root system. The fungus receives sugars produced by the plant through photosynthesis, something it cannot make on its own. In exchange, the fungus extends the plant's effective root system many times over, reaching water and mineral nutrients, particularly phosphorus and nitrogen, that the plant's roots alone couldn't access.
This relationship is not rare or exotic. According to research summarized by the Botanical Society of America, an estimated 80 to 90 percent of all land plant species form mycorrhizal associations. It is, in evolutionary terms, closer to the rule than the exception, a partnership dating back over 400 million years that coincides with plants' initial colonization of land.
What makes the network more than a series of one-to-one partnerships is that a single fungal individual can connect to multiple trees simultaneously, and multiple fungal species can overlap across a forest floor. The result is a web, not metaphorically but structurally, linking trees of the same species, different species, different ages, and different sizes into a shared underground system.
Common Mycorrhizal Networks
Ecologists use the term Common Mycorrhizal Network, or CMN, to describe this shared infrastructure. Research led by forest ecologist Suzanne Simard, beginning with her doctoral work in the 1990s and published in Nature in 1997, provided some of the first direct evidence that carbon could move between trees of different species through these fungal connections. The transfer was not just theoretical but measurable, using radioactive and stable isotope tracing.
The "Mother Tree" Hypothesis
Simard's research introduced one of the most discussed ideas in forest ecology: the "mother tree." Her work suggested that large, old trees act as hubs within mycorrhizal networks, connecting with surrounding trees, including younger seedlings.
In her studies of Douglas fir forests in British Columbia, Simard found evidence that older trees could transfer resources to younger plants through these fungal connections, challenging the traditional view of forests as systems driven only by competition.
This idea of hidden connections within nature has also inspired modern botanical skincare. HAOMA's Mycelium Eye Cream draws inspiration from the world of fungi and the unseen networks that support natural systems, reflecting a broader appreciation for balance, resilience, and the intelligence found throughout nature.
It is worth noting that this area of research remains actively studied, with scientists continuing to explore how much resource exchange benefits individual trees versus the wider fungal network. What is well established is that these physical connections exist and play an important role in shaping forest ecosystems.
More Than Just Nutrients: Chemical Signals
Beyond nutrient sharing, several studies have explored whether mycorrhizal networks can also transmit signals related to stress and threat. Research by ecologists including Simard and collaborators has found evidence that when one plant experiences stress from insects or pathogens, connected plants may activate their own defense responses, as if a warning has traveled through the fungal network.
The exact mechanisms remain an active area of research, and scientists continue to study whether these responses represent true communication or the movement of chemical signals through shared systems. What is clear is that these underground networks influence how plants interact with their environment.
This understanding of hidden biological systems has inspired modern botanical skincare. HAOMA's Mycelium Eye Cream reflects this fascination with the unseen relationships found throughout nature, drawing inspiration from the world of fungi and the delicate balance of living systems. Like the forest networks beneath the soil, the skin is also constantly responding, adapting, and maintaining its own natural balance through processes we cannot always see.
A Forest Floor Full of Old Growth You'll Never See
To understand the scale of this system, consider what a single teaspoon of healthy forest soil contains: potentially several kilometers of fungal hyphae, according to estimates from soil ecology research. Multiply that across an entire forest floor and the mycorrhizal network becomes, by length, one of the largest living structures on the planet. It vastly exceeds the combined length of the forest's visible root systems and branches.
Some individual fungal networks are almost unimaginably old and large. A well-known example is a honey fungus (Armillaria) network discovered in Oregon's Malheur National Forest, estimated by U.S. Forest Service researchers to span roughly 2,400 acres and to be several thousand years old. It is often cited as one of the largest known living organisms on Earth by area, though its exact age remains an estimate rather than a precisely dated figure.
Why This Changes How We Think About Forests
For much of the twentieth century, ecology was dominated by a competitive framework: trees fighting for sunlight, water, and soil nutrients, with the fittest individuals winning out. Mycorrhizal network research doesn't erase competition from the picture. Trees absolutely do compete for light and resources. Instead, it adds a second, cooperative layer running alongside it.
This has practical implications for how forests are managed. Clear-cutting practices that remove large, old "hub" trees may disrupt the network's structure in ways that affect the survival of younger trees far more than previously understood. Some forestry researchers now advocate retaining a scattering of large, well-connected trees during selective harvesting, specifically to preserve network integrity for regenerating stands. This approach is informed directly by mycorrhizal research.
It also reframes how we might think about diversity. Forests with a greater diversity of tree and fungal species tend to have more complex, resilient mycorrhizal networks that are better able to buffer against drought, disease, and other stresses. It is an ecological argument for biodiversity that operates below the soil line, invisible but foundational.
What This Teaches Beyond the Forest
There's a reason the "Wood Wide Web" concept has captured public imagination well beyond ecology circles. It offers a model of interdependence that feels instructive, even if the science resists easy metaphor. A forest, it turns out, thrives not through the strength of its individual members alone, but through the density and health of the connections between them.
This idea of connection extends beyond the forest and into our own daily rituals. HAOMA's Temple Balm reflects this same appreciation for the relationship between plants, senses, and personal wellbeing. Inspired by botanical traditions, it becomes part of a mindful ritual that reminds us that balance is created through attention, harmony, and our connection with the natural world.
It's worth resisting the temptation to over-anthropomorphize. Trees are not making generous choices in any human sense, and the fungi are pursuing their own evolutionary strategies, not altruism. But the underlying structural fact remains quietly remarkable: an entire forest, humming with exchange, mostly hidden from view, doing more collaborative work in a single cubic foot of soil than we can easily observe in a lifetime of walking among the trees.