Scientists Warn: Vital Underground Fungi Networks Face Extinction Risk

Underground fungal networks crucial to Earth’s ecosystems are in urgent need of conservation, according to a new study by the Society for the Protection of Underground Networks (SPUN).

Researchers found that 90 percent of mycorrhizal fungi biodiversity hotspots exist in unprotected ecosystems. The loss of these fungi could reduce carbon sequestration rates, lower crop productivity, and weaken ecosystems' resilience to climate extremes, the study warns.

Mycorrhizal fungi form symbiotic relationships with plants, cycling nutrients, storing carbon, and supporting plant health. “When we disrupt these critical ecosystem engineers, forest regeneration slows, crops fail and biodiversity above ground begins to unravel,” said Dr. Toby Kiers, SPUN’s executive director, in a statement to *The Guardian*.

Forty-five million years ago, Earth had no plants until mycorrhizal fungi enabled plant colonization, ultimately supporting human life. Healthy fungal networks, Kiers noted, contribute to greater agricultural productivity, more resilient ecosystems, and protection against plant pathogens.

The study, published in *Nature*, analyzed over 2.8 billion fungal sequences from 130 countries to create high-resolution maps of global mycorrhizal fungal biodiversity. “For centuries, we’ve mapped mountains, forests, and oceans. But these fungi have remained in the dark, despite the extraordinary ways they sustain life on land,” Kiers said in an SPUN press release. “This is the first time we’re able to visualize these biodiversity patterns — and it’s clear we are failing to protect underground ecosystems.”

Mycorrhizal fungi regulate ecosystems and climate by forming underground networks that provide nutrients to plants and sequester over 13 billion tons of carbon annually—about a third of global fossil fuel emissions. Despite their role, these fungi have been overlooked in climate strategies, conservation plans, and restoration efforts.

The study found that only 9.5 percent of fungal biodiversity hotspots fall within protected areas. “For too long, we’ve overlooked mycorrhizal fungi. These maps help alleviate our fungus blindness and can assist us as we rise to the urgent challenges of our times,” said Dr. Merlin Sheldrake, SPUN’s impact director.

SPUN was launched in 2021 to map underground fungal networks and provide tools for policymakers, conservationists, and climate scientists. The organization aims to identify fungal biodiversity hotspots, prioritize conservation interventions, and establish protected areas.

The study’s lead author, Dr. Michael Van Nuland, emphasized the broader implications: “Food security, water cycles, and climate resilience all depend on safeguarding these underground ecosystems.”

The research includes contributions from prominent advisors such as conservationist Jane Goodall, authors Paul Hawken and Michael Pollan, and fungi expert Giuliana Furci. SPUN’s goal is to make underground biodiversity as central to environmental decisions as satellite data.

Restoration efforts have historically focused on aboveground ecosystems, but SPUN’s maps provide a quantitative foundation for restoring mycorrhizal diversity. “These high-resolution maps provide targets for restoration managers to establish what diverse mycorrhizal communities could and should look like,” said Dr. Alex Wegmann, a lead scientist at The Nature Conservancy.

SPUN’s global team of 96 “Underground Explorers” from nearly 80 countries has sampled remote and hard-to-access ecosystems, including those in Bhutan, Mongolia, Ukraine, and Pakistan. Despite covering only 0.001 percent of Earth’s surface, the dataset already includes over 40,000 specimens representing 95,000 mycorrhizal fungal taxa.

The findings underscore the need for immediate action to protect these vital yet overlooked ecosystems. “These maps reveal what we stand to lose if we fail to protect the underground,” Kiers said.