Scientists have mapped a vast underground network of microscopic fungi that stretches approximately 110 quadrillion kilometres across Earth’s topsoil. This distance is so significant it could theoretically reach the Sun nearly a billion times. The discovery highlights the crucial role these ancient fungal networks play in supporting life on Earth, including aiding plant growth, storing carbon, and maintaining ecosystem health.
The study was led by researchers from the Society for the Protection of Underground Networks (SPUN), who analysed over 16,000 soil samples. They created a detailed map of arbuscular mycorrhizal fungi, which form partnerships with plant roots. Although these fungi are invisible to the naked eye, they create one of the largest biological systems on the planet. The 110 quadrillion kilometres reflects the total length of many networks, not a single organism encircling the Earth.
These fungi form mutually beneficial relationships with around 70% of land plants. In this partnership, plants supply sugars to the fungi, while the fungi assist in absorbing water and essential nutrients like phosphorus. This relationship has existed for millions of years and has been vital for plants colonising land.
The study also reveals that fungal networks are declining in agricultural areas due to practices like deep tilling and excessive fertiliser use. Such changes can lead to crops becoming increasingly dependent on synthetic fertilisers, jeopardising their resilience.
Looking ahead, researchers believe that protecting and restoring these hidden fungal ecosystems is essential for improving food security and combating climate change. Conservation efforts should also focus on these crucial underground systems, which are often overlooked despite their importance.
