Overview
- The peer-reviewed study published in mid-June 2026 estimates about 110 quadrillion kilometres of arbuscular mycorrhizal fungal hyphae in topsoils, roughly 300 megatons of carbon, and about 4 billion tonnes CO2e moved into soils each year.
- Researchers built the estimate by combining data from 322 studies with more than 16,000 soil cores, over 4,000 hyphal-density measurements, robotic imaging of more than 300,000 lab-grown hyphae, and machine-learning models.
- Model results show roughly 40 percent of AM fungal biomass is concentrated in grasslands with hotspots such as the Florida Everglades, the Tibetan Plateau and South Sudan, while large-scale croplands have about half the network density of uncultivated land.
- The team cautions the totals are model-based because deserts, tropical forests, tundra and deeper soil layers are poorly sampled, and they describe the released Mycorrhizal Infrastructure Map as a living dataset to be refined with further sampling.
- By releasing a 1 km² map and downloadable data, the authors aim to help governments, researchers and farmers monitor fungal health, target conservation where networks are richest, and explore agricultural practices that could restore soil fungi to boost carbon storage and crop resilience.