A groundbreaking global study has revealed that over 90% of Earth underground fungal biodiversity hotspots are unprotected raising alarms over a hidden ecosystem that vital to combating climate change boosting crop productivity, and maintaining biodiversity.
Scientists from the Society for the Protection of Underground Networks (Spun) have unveiled the first high-resolution global maps of mycorrhizal fungi networks living beneath the soil that connect plant roots and regulate ecosystem health. The maps show that only 9.5% of these biodiversity-rich zones fall within legally protected areas, leaving the majority exposed to human threats like deforestation, land degradation, and climate stress.
“These fungi are ecosystem engineers,” said Dr Toby Kiers, executive director of Spun. “They cycle nutrients, store carbon, and make soil. If we disrupt them, we risk slowing forest regeneration, increasing crop failure, and unraveling above-ground biodiversity.”
Mycorrhizal fungi are responsible for drawing over 13 billion tonnes of CO₂ into the soil annually about one-third of the emissions from fossil fuels. They’ve existed for 450 million years and were critical in helping plants colonize land.
Using machine learning on more than 2.8 billion fungal samples from 130 countries, researchers predicted fungal diversity at a 1 km² scale. This is the largest study of its kind, giving conservationists a powerful new tool. For example, Ghana’s coast emerged as a major hotspot but with its shoreline eroding at 2 meters per year, scientists fear this unique underground life could be lost to the sea.
Dr Michael Van Nuland, the lead author, emphasized that the findings are “more than scientific data they’re a roadmap for conservation action.” He warned that continuing to ignore fungal ecosystems would be a “hugely missed opportunity” in the fight against climate change.
The research has revealed another gap: fungi are largely invisible in legal frameworks and environmental policy. “It’s frustrating that no action has been taken to prioritize their conservation,” added Kiers. “These organisms are essential for agricultural productivity and human health, yet remain overlooked.”
With support from over 400 scientists and 96 underground explorers across 79 countries, Spun is calling for urgent policy change and funding to expand mapping efforts currently covering just 0.001% of Earth’s surface.
Spun’s interactive Underground Atlas now enables researchers and governments to identify and act on fungal hotspots. The World Wide Fund for Nature’s chief scientist Dr Rebecca Shaw said fungal preservation could be the key to solving multiple global challenges, from biodiversity collapse to food insecurity.
“Healthy fungal networks are directly linked to healthier crops, better climate regulation, and even more beautiful flowers,” said Kiers. “Protecting them is no longer an option—it’s a necessity.”