Researchers have mapped vast fungal networks underground and there's much more to fungi than the mushrooms we see above the surface. Jan Stria/Shutterstock Beneath our feet lie some of the largest living organisms on Earth. Fungi are mostly invisible and largely overlooked, but they help sustain the ecosystems and food systems that we depend on every day. In a new global study, colleagues and I have mapped Earth’s vast underground networks of arbuscular mycorrhizal fungi. These fungi are invisi