Trees secretly talk to each other underground. They’re passing information and resources to and from each other through a network of mycorrhizal fungi—mykós means fungus and riza means root in Greek—a mat of long, thin filaments that connect an estimated 90% of land plants. Scientists call the fungi the Wood Wide Web because ‘adult’ trees can share sugars to younger trees, sick trees can send their remaining resources back into the network for others, and they can communicate with each other about dangers like insect infestations.
The relationship between these mycorrhizal fungi and the plants they connect is now known to be ancient (around four hundred and fifty million years old) and largely one of mutualism—a subset of symbiosis in which both organisms benefit from their association.
In the case of the mycorrhizae, the fungi siphon off food from the trees, taking some of the carbon-rich sugar that they produce during photosynthesis. The plants, in turn, obtain nutrients such as phosphorus and nitrogen that the fungi have acquired from the soil, by means of enzymes that the trees do not possess…
The revelation of the Wood Wide Web’s existence, and the increased understanding of its functions, raises big questions—about where species begin and end; about whether a forest might be better imagined as a single superorganism, rather than a grouping of independent individualistic ones; and about what trading, sharing, or even friendship might mean among plants.