Earth's underground fungal network is so massive, it would span 10% of the Milky Way, map reveals

Key Points:

• A new study has mapped Earth's underground arbuscular mycorrhizal fungal networks, revealing that if laid end-to-end, these fungal hyphae would span about 10% of the Milky Way galaxy, highlighting their vast global presence.
• These fungi form symbiotic relationships with most land plants, exchanging nutrients like nitrogen and phosphorus for carbon, and are especially dense in high-altitude and flooded grasslands, which serve as critical carbon sinks.
• The study found that agricultural practices significantly reduce fungal network density, with cropland topsoil containing roughly 50% less fungal biomass compared to wild grasslands, potentially due to fungicides and fertilizer use.
• Researchers compiled data from over 16,000 soil samples worldwide and used AI to predict fungal distribution, but noted that more sampling is needed in regions like tropical rainforests and deserts to improve the map's accuracy.
• Experts emphasize the importance of this map for biodiversity conservation, agricultural management, and climate change mitigation, while calling for further research on the fungi's functional roles and dynamics in soil carbon cycling.