The hidden fungal networks keeping nature in balance
The deeper you dig into the kingdom Fungi—which includes yeasts, molds, mildews, mushrooms, and other life-forms—the more you realize how essential its species are. Fungi live in the air, ground, water, and even our bodies. Without them, we wouldn’t have healthy forests or soils, life-saving medicines like penicillin, or sourdough bread and beer. But researchers have only just begun to unearth the secrets of these captivating organisms.
© Spectacular Rustgill © Mike Read/naturepl.com; Fly Agaric © Guy Edwardes/2020Vision/naturepl.com; Dirt © David Bebber/WWF-UK
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> 5 million species
Scientists have identified around 150,000 fungal species, but researchers estimate the true number could exceed five million, based on environmental DNA analyses and predictive modeling. At the current rate of discovery, documenting them all could take centuries.
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279.6 quadrillion miles
Total length of mycorrhizal mycelium in the top 10 centimeters of the world’s soil—almost half the width of our galaxy.
Mycelium: the branching, root-like main body of a fungus
Mycorrhizal fungi live in the soil and form symbiotic relationships with nearly 90% of plant species—alliances that date back roughly 475 million years. Through vast networks of thread-like structures called mycelium, the fungi exchange nutrients for carbon-rich compounds produced by plants, distributing important resources across ecosystems. A single gram of healthy soil—about a quarter of a teaspoon—can contain up to hundreds of meters of mycelium.
© David Bebber/WWF-UK
FINDING YOUR ROOTS
Fungi are more closely related to animals than plants. While plants and fungi diverged early in evolutionary history, fungi and animals have a more recent common ancestor—and fungi share roughly half of their DNA with humans.
HIDDEN HEROES
Fungi act as Earth’s cleanup crew. By secreting specialized digestive enzymes, they break down complex organic matter and turn it into simpler structures—a process that fuels plant growth, neutralizes toxic pollutants, traps heavy metals, and clears away organic debris while supporting healthy soils. Some species, such as Aspergillus tubingensis, have even been shown to degrade certain plastics, offering a potential tool in addressing the plastic waste crisis.
UNDERGROUND ATLAS
The Society for the Protection of Underground Networks (SPUN) recently created the first-ever biodiversity map of the world’s mycorrhizal fungal networks. Built from more than 2.8 billion fungal DNA sequences collected across 130 countries, the project identified hotspots of underground fungal diversity and found that less than 10% lie inside protected areas—data that SPUN is using to help identify conservation priorities.
© Juozas Cernius / WWF-UK
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