Global mapping reveals 110 quadrillion kilometers of mycorrhizal networks in topsoils
spun authors
summary
Mycorrhizal fungi form a vast hidden infrastructure beneath Earth's surface, linking plants, soils, and carbon cycles. Making this invisible network visible is essential for conserving biodiversity, restoring ecosystems, and addressing climate change. Mycorrhizal fungi form an immense underground network that supports approximately 70% of terrestrial plant species.
Arbuscular mycorrhizal fungi form one of the largest living networks on Earth, with an estimated 110 quadrillion kilometers of fungal filaments beneath our feet. Protecting these underground networks is essential for maintaining healthy ecosystems, productive soils, and resilient landscapes.
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The study aimed to:
- Estimate the global density and biomass of AM fungal networks.
- Identify where these fungal networks are most abundant across Earth's ecosystems.
- Determine which environmental factors drive fungal density.
- Assess how land-use change, particularly agriculture, affects AM fungal abundance.
Researchers compiled one of the largest global datasets of AM fungal hyphal density from field studies and experiments. They then used machine-learning models to predict fungal abundance across different biomes worldwide.
To estimate biomass, they combined:
- Field measurements of hyphal density,
- High-resolution imaging of fungal networks grown under controlled conditions,
- Global environmental and land-cover datasets.
Take-aways:
- These fungal networks transport nutrients and water to plants while moving large amounts of plant-derived carbon into soils, making them fundamental to ecosystem functioning and carbon cycling.
- Global estimates suggest that AM fungal networks extend for roughly 110 quadrillion kilometers (621 trillion miles) within the planet's topsoils and contain hundreds of megatons of carbon.
- Grasslands contain a substantial proportion of this underground infrastructure, yet they remain among the world's least protected ecosystems.
- Many fungal biodiversity hotspots occur outside protected areas, making these ecosystems particularly vulnerable to land-use change and agricultural conversion.
Summary:
Beneath the soil lies a vast hidden network of fungi that helps plants obtain nutrients and water. This study produced the first global map of these underground fungal threads and found that they stretch for an astonishing 110 quadrillion kilometers in the topsoil alone.
The researchers discovered that grasslands contain some of the densest fungal networks on Earth, while farmland often has far fewer fungi than natural ecosystems. On average, agricultural soils contain about half the fungal density found in non-cultivated land.
These findings reveal that mycorrhizal fungi are a critical but often overlooked part of Earth's life-support system. Protecting these underground networks could help improve soil health, support biodiversity, and strengthen ecosystem resilience in a changing world.
