In a greenhouse at the University of Kansas, Professor Liz Koziol and Dr. Terra Lubin tend to rows of Sudan grass, each plant harbouring a specific strain of invisible soil fungi. These samples are part of the International Collection of Vesicular Arbuscular Mycorrhizal Fungi (INVAM), the world’s largest living library of soil fungi. But this irreplaceable collection is in danger of closing due to federal budget cuts.
INVAM, which has been four decades in the making, maintains living spores of more than 900 distinct fungal strains collected from six continents. These fungi are essential “ecosystem engineers” that support the growth of 70% of land plant species, providing them with vital nutrients and protecting them against drought and disease. They also play a crucial role in restoring degraded ecosystems, rebuilding damaged soils, and reducing the need for artificial fertilizers.
However, the future of INVAM hangs in the balance. Its latest funding from the US National Science Foundation (NSF) ended in May, and the Trump administration’s proposed budget for fiscal year 2026 would slash NSF funding by 57%, making it even more difficult to secure new grants. Without additional funding, the collection may be forced to close within a year, according to Professor Jim Bever, the curator and team leader.
“INVAM represents a library of hundreds of millions of years of evolution,” said Toby Kiers, executive director of the Society for Protection of Underground Networks (Spun). “Ending INVAM for scientists is like closing the Louvre for artists.”
The loss of INVAM would be catastrophic for mycological research worldwide. Unlike seed banks or frozen cell samples, the spores of arbuscular mycorrhizal (AM) fungi require sustained, meticulous work to maintain. At INVAM, associate curator Lubin carefully isolates and identifies these spores, then cultivates them on Sudan grass seedlings to produce new generations of the fungi.
The importance of these fungi extends beyond academic research. Their practical applications include restoring degraded ecosystems, improving soil health, and reducing the need for synthetic fertilizers in agriculture. However, the commercial market for fungal biofertilizers is rife with low-quality products that fail to effectively colonize plant roots.
“Unfortunately, the quality of most products available to farmers or restoration practitioners is really just terrible,” said Bever, who has found that the majority of commercial AM fertilizers are worthless.
The potential of these fungi is evident in the successful prairie restoration experiment conducted by Bever and Koziol. Nine years ago, a tired old hay field was transformed into a vibrant, diverse prairie ecosystem simply by seeding it with native plants and AM fungal spores. This demonstrates the power of these fungi to drive ecological restoration and support sustainable agriculture.
“The benefits of mycorrhizal fungi are real,” said Bever. “Yet scientists are only beginning to understand how these organisms work. Numerous research questions can only be answered with living libraries such as INVAM.”
Without federal investment in basic science, the future of INVAM and the crucial role it plays in understanding and harnessing the power of these fungi is uncertain. Mycologists and ecologists around the world are calling for action to save this vital collection before it’s too late.