Scientists map massive layer of life just beneath our feet

our Twitter (X) feedView our Youtube channelView our Instagram feedView our Substack feedView our Spotify feed Until recently, nobody had visualized the fungal "Wood Wide Web." This global underground network is invisible to the naked eye, yet is more than five times the weight of all humans on Earth. ( Science and TechClimate ChangeEarth ScienceEnvironmentConservation Ecology Directly beneath our feet stretches a world both smaller and much, much larger than the one we know. Scientists have just begun mapping what may well be the largest piece of infrastructure on Earth: a network of fungal threads that is 68 _quadrillion_ miles long. And we thought we’d mapped just about everything there is to map on this planet: continents, voting patterns, bird migration routes, alleged apparitions of the Virgin Mary, and Starbucks locations near you.

We’ve logged and named almost every fold of the visible world. And yet until June, the most extensive piece of infrastructure on the planet had not been extensively mapped. This network is larger than every road, cable, and shipping lane combined.

A map of the fungal network in North America; on the right, a close-up of its capital –Florida. ( To be precise: It’s fungal. This underground network is made of so-called _hyphae_: hair-thin filaments that knit together into vast structures known as _mycelium_. A large fraction of these fungi form partnerships with the roots of plants and trees.

Roughly 70% of all botanical species indulge in these relationships. Think of these relationships, also known as _mycorrhizae_, not so much as tender friendships, but as shrewd trade agreements: Both parties get something indispensable out of it. The plant can make sugar from sunlight, but is bad at foraging.

So the fungus provides phosphorus, nitrogen, and water. The fungus is a foraging superhero, but cannot photosynthesize. So the plant repays the fungus in carbon.

The arrangement is not new — it dates back several hundred million years, to when plants were first figuring out how to survive on land. What’s new is that scientists have now learned to map the actual shape and extent of that arrangement. Get the fall print issue, shipping in October, to members only.