Full Breakdown
Global Mapping Reveals Vast Underground Fungal Infrastructure
6/17/2026, 4:52:30 AM
Mapping the Hidden Web
Scientists from the Society for the Protection of Underground Networks (SPUN) combined >16,000 soil cores from 322 studies, climate and vegetation data, and robotic imaging of >300,000 hyphae. Machine-learning predictions for every 1 km² of vegetated land estimate roughly 110 quadrillion kilometers (?62 quadrillion miles) of arbuscular mycorrhizal hyphae in topsoil—enough for a billion Earth-Sun trips. Average topsoil holds about 4.4 m of hyphae per cm³, or up to 10 m in a teaspoon of soil.
Hotspots and Agricultural Loss
Wild grasslands contain about 40 % of global mycorrhizal biomass, with the highest densities in the Everglades (USA), the Sudd wetlands (South Sudan), the Tibetan Plateau, the Anatolian steppe, and the Flint Hills Prairie (USA). By contrast, large-scale croplands show roughly 50 % lower hyphal density, a loss linked to tillage, synthetic fertilizers and fungicides.
Climate Role
The networks move an estimated 4 billion tons of CO2-equivalent into soils each year—about 11 % of anthropogenic emissions—thereby enhancing long-term carbon storage and soil water retention.
Official Statements & Responses
Lead author Dr. Justin Stewart said the study highlights the enormous ecological importance of arbuscular mycorrhizal fungi and that the interactive map can guide protection and restoration of high-density areas. Executive director Dr. Toby Kiers cautioned that loss of these networks could increase chemical runoff into waterways and urged that fungal metrics be incorporated into global conservation targets. The team plans to present the findings at the upcoming United Nations climate conference.
Criticism & Gaps
Independent mycologists describe the map as a “first draft” and note large unsampled zones in deserts, Greenland and tropical interiors. Conservationists point out that only ~10 % of the densest clusters lie within protected areas, leaving the infrastructure vulnerable.
Conflicting Reports & Gaps
Source 1 lists network length as 62 quadrillion miles, while other sources give 110 quadrillion kilometers; the difference reflects unit conversion. Mass estimates range from “roughly 300 megatonnes of carbon” to “four to six times the total mass of all living humans.” Data gaps remain in many regions.
Verbatim Quotes
- “Mycorrhizal symbiosis is a cooperation between plants and fungi that’s quite ancient, about 450 million years old,” — Justin Stewart, Evolutionary Biologist, SPUN
- “Until we invent magical glasses…they basically appear invisible to us.” — Anne Pringle, Mycologist, University of Wisconsin-Madison
- “If they disappear, there’s going to be a lot more chemicals going into waterways,” — Toby Kiers, Executive Director, SPUN
- “[But] grasslands can be extremely ancient and extremely diverse.” — Giuliana Furci, Executive Director, Fungi Foundation
What’s Next
Researchers will add field samples from under-studied regions, refine the model, and work with policymakers to embed fungal metrics in climate and land-use strategies.
