Stand in a forest and you see separate trees, each on its own. Walk a metre under your feet and the picture changes entirely.
A web under the floor
Fine root tips are almost always wrapped in a thin coat of fungus. That fungus — mycorrhiza — reaches into the soil far beyond where the roots can go, trading water and nutrients back to the tree in exchange for sugars the tree makes from sunlight. Neither partner does well alone.
And here’s the twist: the fungus doesn’t only connect one tree to the soil. It connects trees to each other. Roots and fungal threads knit the forest floor into a single, shared network — a living internet with data flowing as chemistry.
What flows across the network
Trees send sugars to neighbours that need them — a shaded seedling, a tree recovering from damage. They also send warning signals. When one tree is attacked by insects, it can raise chemical defences, and trees connected to it through the network often raise theirs in advance.
Not every scientist agrees on how much this counts as “communication” rather than chemistry. But everyone who studies the soil agrees the exchange is real, constant, and far bigger than we used to think.
Mother trees
In many forests, the largest, oldest trees — “mother trees” — are the hubs. Their root systems are connected to dozens or hundreds of younger trees. Cut down a mother tree and you don’t just remove one trunk; you remove a point where the whole neighbourhood was wired together.
What this means for planting
It’s a strong argument for restoring forests the way they actually work: mixed species, native plants, and soil left intact. A monoculture row of identical saplings, planted on cleared ground, has no network to plug into. A diverse forest plugs itself back together — given time, and given the chance.