Soil and water

Vast global underground fungal networks to be mapped for the first time | Mushrooms


Vast networks of underground fungi – the “planet’s circulatory system” – need to be mapped for the first time, in an attempt to protect them from damage and improve their ability to absorb and store carbon dioxide.

Fungi use carbon to build networks in the soil, which connect to plant roots and act as nutrient “highways”, exchanging carbon from plant roots for nutrients. For example, some fungi are known to provide 80% phosphorus to their host plants.

Underground fungal networks can stretch for several miles, but are rarely noticed, although billions of miles of them exist around the world. These fungi are vital for soil biodiversity and soil fertility, but little is known about them.

Many hotbeds of mycorrhizal fungi are said to be threatened by the expansion of agriculture, urbanization, pollution, water scarcity and climate change.

The new project, by the Society for the Protection of Underground Networks (SPUN), will involve the collection of 10,000 samples around the world, from hot spots identified using artificial intelligence technology.

Jane Goodall, the ecologist, who advises the project, said: “An understanding of underground fungal networks is essential to our efforts to protect the soil, on which life depends, before it is too late. “

The Society for the Protection of Underground Networks includes scientists from the Netherlands, Canada, the United States, France, Germany and the University of Manchester in the United Kingdom.

The first collections will take place next year in Patagonia, and will continue for about 18 months, to create maps of potential underground mycorrhizal fungi that can be used for further research. Using the maps, scientists hope to identify ecosystems facing the most pressing threats and partner with local conservation organizations to try to create “conservation corridors” for underground ecosystems.

It is believed to be the first major effort to map an underground ecosystem in this way. Climate science has focused on aerial ecosystems, and while we know that fungi are essential for soil structure and fertility, as well as the global carbon cycle, ecosystems with Thriving mycorrhizal fungal networks store eight times more carbon than ecosystems without such networks – much of the role of fungi in soil nutrient cycling remains a mystery.

Mark Tercek, former CEO of Nature Conservancy and member of the governing body of SPUN, said: “Fungal networks underpin life on Earth. If trees are the “lungs” of the planet, fungal networks are the “circulatory systems”. These networks are largely unexplored.

Mycorrhizal fungi create stubborn organic compounds that structure the soil and store carbon in their necromass, networks that are no longer active, but remain woven into the soil.

Modern industrial agriculture adds large amounts of chemical fertilizers that interrupt the dynamics of exchanges between plants and fungi, scientists warn. Without thriving fungal networks, crops require more chemical inputs and are more vulnerable to drought, soil erosion, pests and pathogens. Mechanical plowing in modern agriculture also damages the physical integrity of fungal networks.

There is also growing evidence that certain combinations of fungi can improve productivity more than others, so protecting them is essential, according to soil scientists.

Ten hot spots were identified by the scientists involved, including: the Canadian tundra; the Mexican plateau; high altitudes in South America; Morocco; Western Sahara; the Negev Desert in Israel; the steppes of Kazakhstan; the prairies and high plains of Tibet; and the Russian taiga.

Jeremy Grantham, a billionaire financier and climate research funder who is funding the project with $ 3.5million (£ 2.6million), said: ‘Right under our feet is an invaluable ally to mitigate climate change: vast hidden fungal networks. Billions of tons of carbon dioxide flow from plants into fungal networks each year. However, these carbon sinks are poorly understood. By working to map and exploit this threatened but vital resource for life on earth, SPUN is opening a new chapter in global conservation.