Inside a large greenhouse at the University of Kansas, Professor Liz Koziol and Dr Terra Lubin tend rows of sudan grass in individual plastic pots. The roots of each straggly plant harbor a specific strain of invisible soil fungus. The shelves of a nearby cold room are stacked high with thousands of plastic bags and vials containing fungal spores harvested from these plants, then carefully preserved by the researchers.

The samples in this seemingly unremarkable room are part of the International Collection of Vesicular Arbuscular Mycorrhizal Fungi (INVAM), the world’s largest living library of soil fungi. Four decades in the making, it could cease to exist within a year due to federal budget cuts.

For leading mycologist Toby Kiers, this would be catastrophic. “INVAM represents a library of hundreds of millions of years of evolution,” said Kiers, executive director of the Society for Protection of Underground Networks (Spun). “Ending INVAM for scientists is like closing the Louvre for artists.”

The arbuscular mycorrhizal (AM) fungi conserved by INVAM are symbiotic organisms that support the growth of 70% of land plant species across all ecosystems. In exchange for sugars and fats, they provide plants with vital nutrients – phosphorus, nitrogen, trace metals – and buffer them against drought, disease and other stressors. They also represent a substantial underground sink for carbon dioxide.