Fungi take up more mass than people—see how they stretch across the Earth

Using machine-learning models and evidence from thousands of soil cores, scientists also found that a single type of fungus—called arbuscular mycorrhizal fungi—collectively weigh 300 megatons, four to six times the mass of every human on the planet. The tiny hyphal fingers of these networks reach far enough to stretch from Earth to the sun and back nearly a billion times.

“It really challenges the assumption of plants as stand alone organisms and forces us to think about how organisms are involved in a myriad of interactions that we don’t see,” says Toby Kiers, a study author and evolutionary biologist at Vrije University in Amsterdam.

Kiers is also the executive director of SPUN, the Society for the Protection of Underground Networks, and says knowing where these fungi hotspots are, and protecting them, could even limit climate change.

Why fungi networks are essential

Plants take in water and nutrients such as phosphorus and nitrogen through their roots. But most plants also have help absorbing these nutrients. They are in a symbiotic relationship—a type of partnership—with arbuscular mycorrhizal fungi.   

“Mycorrhizal symbiosis is a cooperation between plants and fungi that’s quite ancient, about 450 million years old,” says Justin Stewart, an evolutionary biologist with SPUN, who is also a study author. “You have plants that take carbon dioxide in through photosynthesis, and then they feed this to these bodies of mycelium in soil,” Stewart, who’s also a study author, says.