Do trees really talk to each other through fungi?

Trees really are wired together underground, but whether they "talk" is still hotly debated. The wiring is real: fungal threads called hyphae grow into and around tree roots, forming a mycorrhizal network that links neighbouring plants. The deal at its core is solid science. A plant hands its fungus up to 30% of the carbon it makes by photosynthesis, and the fungus pays back in scarce nutrients like nitrogen and phosphorus.

The exciting part came from Suzanne Simard, a forest ecologist who grew up in Canadian forests in a family of foresters. In 1997 she showed that these networks connect trees, and later experiments with traceable carbon found carbon moving between paper birch and Douglas fir in both directions, changing with the seasons. Another study saw ponderosa pines ramp up defensive enzymes after Douglas firs connected to them were attacked by budworm. The press called it the "Wood Wide Web".

Then came the pushback. In 2023, three publications by experts in the field argued that popular ideas about the network, that it is widespread, that it helps seedlings, that older trees favour younger ones, had gone beyond what field studies actually observed. The "mother tree" idea in particular has been questioned for lacking evidence and for turning plants into people. The critics also pointed to positive citation bias: scientists preferentially repeating the exciting results.

So the honest answer: the fungal links exist and some carbon moves between trees, but a forest-wide chat of warnings and gifts is not yet proven.