Scientists just dropped what might be the most important map you've never heard of.
The Society for the Protection of Underground Networks (SPUN) published research in Nature this year revealing something shocking.
They've created the first high-resolution map of Earth's underground fungal networks, and found that 90% of the most biodiverse hotspots are completely unprotected. They're not even on our radar for conservation.
And that's pretty worrying for anyone who kind of likes living on Earth.
The Networks That Built Our World
If you don't know about mycorrhizal fungi, prepare to have your mind blown. 450 million years ago, there were literally no plants on Earth. And it was these fungal networks that made it possible for plants to colonise land in the first place. So they're not just a part of the ecosystem, they are the foundation of all life on Earth.
Dr. Toby Kiers, SPUN's executive director, puts it perfectly. She says that fungi have "remained in the dark, despite the extraordinary ways they sustain life on land." They're cycling nutrients, storing carbon, keeping soil healthy, protecting plants from disease. The invisible architects of everything green you've ever seen.
And they're pulling roughly 13 billion tons of CO₂ out of the atmosphere every year. That's about one-third of all global fossil fuel emissions. So while environmental efforts have focused on planting trees, we've been overlooking these vital underground organisms.
How They Mapped the Invisible
The SPUN team, working with partners like GlobalFungi and the Global Soil Mycobiome consortium, used machine learning to analyse 2.8 billion fungal DNA sequences from 130 countries. They predicted mycorrhizal diversity at a 1km² scale across the entire planet.
The result was The Underground Atlas - an interactive tool that shows you where these fungal hotspots are, how diverse they are, and (depressingly) how few of them we're actually protecting.
Only 9.5% of fungal biodiversity hotspots fall within existing protected areas. We've got huge conservation gaps everywhere.
Lead author Dr. Michael Van Nuland calls the maps "more than scientific tools" that can "guide the future of conservation." And he's right to emphasise the urgency here. These fungi respond badly to human stressors, and we're running out of time to protect them.
The Stuff That Should Keep Us Up at Night
Ghana's coastline is a global hotspot for fungal diversity. It's also eroding at 2 metres per year. That biodiversity is literally washing into the sea as we speak.
Land use is also destroying mycorrhizal networks everywhere, and as Kiers points out, it's "frustrating that no action has been taken to prioritise conservation of it." These are the same fungi we need for agricultural productivity and human health. We're sawing off the branch we're sitting on.
Without these networks, forest regeneration slows down. Crops fail. The biodiversity we can see above ground starts to unravel. César Rodríguez-Garavito from NYU's More-Than-Human Life program notes these ecosystems have been "largely invisible in law and policy", which is a polite way of saying we've been ignoring them completely.
Why This Matters Right Now
In some ways it's understandable. Invisible underground fungal networks don't have the same PR appeal as polar bears, pandas or coral reefs. But Dr. Rebecca Shaw from WWF is spot on when she says protecting these fungi could help solve "some of the world's greatest challenges: biodiversity decline, climate change, and declining food productivity."
The good news is that SPUN has created something actually useful. The Underground Atlas is available now for conservation groups, researchers, and policymakers to identify hotspots that need intervention. They've got over 400 scientists and 96 "underground explorers" sampling ecosystems in 79 countries, from Mongolia to Bhutan to Ukraine.
The bad new is they've only mapped 0.001% of Earth's surface so far. They're looking for funding and collaborators to scale up.
The Bottom Line
We spent billions mapping the surface of Mars before we bothered mapping the fungal networks that keep Earth alive. That seems short sighted.
But now we have the data. We have the maps. We know where the hotspots are. The question is whether we'll actually do something about it, or if these networks will join the long list of things we understood too late.
Because the reality is that when we disrupt these "ecosystem engineers," as Kiers calls them, we're not just losing some obscure fungi. We're undermining the entire foundation of terrestrial life. The same networks that made it possible for plants and animals to exist on land in the first place.
No pressure or anything.
Explore the Underground Atlas yourself at spun.earth/underground-atlas.
Nature study: Global hotspots of mycorrhizal fungal richness are poorly protected
