Earth's Underground Fungal Networks Span 11 Quadrillion Kilometers, Study Reveals

A groundbreaking international study has quantified the immense scale of underground fungal networks, revealing an estimated 11 quadrillion kilometers of mycelial threads beneath the Earth's surface. This staggering length is equivalent to traveling between the Earth and the Sun 730 million times. These subterranean networks, formed by the thread-like structures of fungi called hyphae, are fundamental to global ecosystems, acting as a vital link between plants and the soil.

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The total length of underground fungal hyphae on Earth is approximately 11 quadrillion kilometers.

These mycorrhizal fungi form symbiotic relationships with plant roots, enabling plants to access nutrients and water from a much wider area than they could on their own. In return, the fungi receive carbon from the plants. The study estimates that the biomass of these fungi in the top 15 centimeters of soil is four to six times greater than the total biomass of humanity. This carbon sequestration role is significant, with fungi estimated to receive 1 billion tons of carbon annually from plants, equivalent to 11% of global human carbon emissions.

The research, published in the journal Science, utilized machine learning models and extensive data from over 16,000 soil cores across nine biomes worldwide. The findings indicate that grasslands are particularly rich in these fungal networks, accounting for 40% of the global mycorrhizal fungal biomass. Areas like the Everglades in Florida, the Sudd wetlands in South Sudan, and various prairie and steppe ecosystems were identified as crucial habitats.

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This length is equivalent to traveling between the Earth and the Sun 730 million times.

Conversely, the study found that agricultural lands exhibit a 47.3% lower density of hyphae compared to uncultivated areas. This reduction is attributed to agricultural practices, including the application of fertilizers, pesticides, and fungicides, which disrupt the formation of these essential networks. The researchers emphasize that uncultivated grasslands serve as critical reservoirs for mycorrhizal fungal biomass.

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The biomass of these fungi in the top 15 centimeters of soil is four to six times greater than the total biomass of humanity.

Lead researcher Justin D. Stuart highlighted that fungi have been overlooked in climate and conservation research for too long. The study underscores the critical need to study and protect these vast, hidden ecosystems beneath our feet, especially as climate change intensifies and carbon cycles are increasingly scrutinized. The findings suggest that preserving these underground networks is essential for maintaining ecosystem health and mitigating climate change.

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Agricultural lands exhibit a 47.3% lower density of hyphae compared to uncultivated areas.