Plant DecodedDo trees really talk through the wood wide web?
The fungi are real. The chatty, nurturing forest is a lot less certain.
By 
Short answer
Probably not the way you’ve heard. Fungi really do partner with tree roots, and some carbon can move between trees. But a 2023 review found no peer-reviewed field study showing that “mother trees” send food or warnings to their seedlings through these fungal networks.
What’s true: trees and fungi are partners
Most land plants team up with mycorrhizal fungi. The fungi wrap around or grow into roots and send thread-like filaments far out into the soil. They bring back water and nutrients like phosphorus, and in return the plant pays them in sugar.
This partnership is ancient, it’s everywhere, and forests depend on it. None of that is in doubt.
Where the “wood wide web” story came from
In 1997, a study in the journal Nature traced carbon moving between birch and Douglas fir trees in a Canadian forest, apparently through shared fungi. Nature’s cover called it the “wood-wide web”, and the name stuck.
Over the next two decades the idea grew. Trees, the story went, are wired together underground, share food with their neighbours, and “mother trees” nurture their seedlings and warn them about insect attacks. It made it into bestselling books, documentaries and even Ted Lasso.
What a 2023 review actually found
Three researchers went back through the field studies and checked three popular claims:
- Fungal networks connecting trees are widespread in forests. There isn’t enough evidence to say so.
- Resources moving through these networks help seedlings grow. The results are mixed, and many studies can’t rule out other routes.
- Mature trees send resources or warnings to their offspring through the network. Not a single peer-reviewed field study supports it.
They also found that later papers tended to cite the original studies as stronger evidence than they really were. Small, careful findings grew into big claims one citation at a time.
So are forests just trees competing?
Not that either. Trees affect each other constantly, through shade, roots, fallen leaves and the soil life they share. Plants also release airborne chemicals when they’re attacked, and there’s decent evidence that neighbours can pick up on some of these signals.
The forest is still full of connections. The specific picture of a caring underground internet just hasn’t been shown yet.
For the curious
Below the surface: why this is so hard to prove
To show that two trees are connected by the same fungus, you need to prove the fungal threads around both root systems belong to the same individual. That takes genetic testing, and the threads are thinner than a hair and break the moment you dig.
Even then, a connection doesn’t prove anything moves through it. In many experiments, carbon or nitrogen tracers could have travelled through the soil, through root contact or through other fungi instead. Separating those routes in a real forest is fiendishly hard, which is exactly why the bold claims got ahead of the data.
How sure are we?
Quick questions
Is the wood wide web real?
Fungi linking some tree roots is real. A forest-wide network that trees use to share food and warnings hasn’t been shown in the field.
Do trees communicate at all?
There’s reasonable evidence that plants respond to airborne chemicals released by damaged neighbours. That’s the best-supported form of plant-to-plant signalling.
Are mycorrhizal fungi good for my plants?
For most plants, yes. Healthy soil with plenty of organic matter supports them naturally.
Sources
- Karst J, Jones MD, Hoeksema JD (2023). Positive citation bias and overinterpreted results lead to misinformation on common mycorrhizal networks in forests. Nature Ecology & Evolution 7: 501–511. Read the paper
- Simard SW, Perry DA, Jones MD, et al. (1997). Net transfer of carbon between ectomycorrhizal tree species in the field. Nature 388: 579–582. Read the paper
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