Overview
- Researchers combined more than 16,000 soil-core measurements, robotic imaging of over 300,000 lab-grown fungal strands, and machine-learning to produce the first high-resolution global estimates of arbuscular mycorrhizal (AM) networks.
- The team estimates roughly 110 quadrillion kilometres of AM hyphae in topsoils worldwide and about 300 megatons of fungal carbon, which the authors say moves an estimated ~4 billion tonnes CO2e into soils each year.
- Wild grasslands concentrate about 40% of AM biomass while large-scale croplands show roughly 50% lower network density, raising concerns that conversion to agriculture could reduce soil carbon storage and nutrient cycling.
- The authors released an interactive Mycorrhizal Infrastructure Map and the underlying open data to help policymakers and researchers target grassland protection, change agricultural practices, and prioritize new field sampling.
- The study builds on prior planetary fungal work such as the Underground Atlas and the 2025 global analyses, but authors warn the model has gaps in poorly sampled biomes and deeper soils that need targeted field work to lower uncertainty.