I'm pulling together the key details from this fungal network research — the scale of it is mind-boggling, with 110 quadrillion kilometers of threads stretching nearly a billion times the Earth-Sun distance, and the Carbon sequestration numbers are huge too. Now I'm thinking about how to structure this into 2-3 paragraphs that build momentum, starting with the sheer scale of what these networks accomplish before diving into the research methodology and findings.
I'm organizing the rest of the key details — the carbon sequestration, the SPUN organization's role, the machine learning approach, the mass comparison to humans, and the conservation concerns like cropland density being half that of wild ecosystems — so I can weave these naturally into a compelling narrative without repeating what I've already covered.
</think>
Yo team — drop everything because we've just learned that the underground fungal networks beneath our feet are so vast they could stretch nearly a billion times the distance between Earth and the Sun, and this new research finally maps them globally for the first time! Researchers have quantified the length and mass of arbuscular mycorrhizal fungi — those ultra-thin thread-like hyphae smaller than a strand of human hair — and the numbers are absolutely bonkers: there are 110 quadrillion kilometers of these living networks worldwide, forming intimate symbiotic relationships with roughly 80 percent of all plant species on the planet. These fungi act as living pipes, transporting nutrients like phosphorus and nitrogen to plants in exchange for carbon, and they sequester an incredible 1 billion tons of carbon underground each year. Without these networks, that carbon would be warming the atmosphere, so they're doing double duty — helping plants grow better while actively drawing carbon down. The new study, published in *Science* on Thursday, was led by Justin Stewart, an evolutionary ecologist at SPUN (Society for the Protection of Underground Networks), and it's a game-changer because for decades we knew these networks existed but had no idea where they were densest, how they were distributed, or how much biomass they actually represented.
The methodology behind this is just as fascinating as the findings — the SPUN team used a combination of literature review, machine learning, and lab testing to create these predictive global maps, pulling from 16,000 geolocated soil samples taken from ecosystems around the world. They even partnered with AMOLF, a research institute in Amsterdam, to develop a robotic camera system that records fungal networks growing over time in the lab, giving them much better estimates of thread widths. The result? The living arbuscular mycorrhizal fungal networks have a total mass of about five times the weight of all humans on Earth. But here's what really got my attention: while wild grasslands hold about 40 percent of the world's arbuscular mycorrhizal biomass, they're among Earth's least protected ecosystems, and grasslands are being converted into farmland at four times the rate of forests. Cropland fungal network densities are about half of what they are in wild ecosystems, and previous research from SPUN found that 90 percent of fungal communities globally are unprotected. Toby Kiers, executive director and co-founder of SPUN, put it perfectly: "This is the moment where we went from knowing that this system exists to really knowing where it is, how dense it is and where it's been."
What's next is going to be wild — the SPUN team will be presenting at COP31 (the United Nations Climate Change Conference) to policymakers about the networks' role in protecting ecosystems and sequestering carbon. Corentin Bisot, an AMOLF biophysicist and co-author, noted that we're still far from having the full "toolbox" to actively increase microbes and fungi in specific areas, and James Bever of the University of Kansas said this study "helps us come to grips with how important these below ground organisms can be to everything that we see above ground." Stewart compared it to the first maps the Spaniards drew of California — which mistakenly presented the state as an island — meaning this is just the first map of fungal networks, and there's plenty more to discover. The study only covers living networks and doesn't include dead fungal networks, which also store carbon and add to total biomass, so there's even more to come.
Source: https://arstechnica.com/science/2026/06/threads-of-underground-fungal-networks-are-long-enough-to-reach-beyond-the-solar-system/
I'm organizing the rest of the key details — the carbon sequestration, the SPUN organization's role, the machine learning approach, the mass comparison to humans, and the conservation concerns like cropland density being half that of wild ecosystems — so I can weave these naturally into a compelling narrative without repeating what I've already covered.
</think>
Yo team — drop everything because we've just learned that the underground fungal networks beneath our feet are so vast they could stretch nearly a billion times the distance between Earth and the Sun, and this new research finally maps them globally for the first time! Researchers have quantified the length and mass of arbuscular mycorrhizal fungi — those ultra-thin thread-like hyphae smaller than a strand of human hair — and the numbers are absolutely bonkers: there are 110 quadrillion kilometers of these living networks worldwide, forming intimate symbiotic relationships with roughly 80 percent of all plant species on the planet. These fungi act as living pipes, transporting nutrients like phosphorus and nitrogen to plants in exchange for carbon, and they sequester an incredible 1 billion tons of carbon underground each year. Without these networks, that carbon would be warming the atmosphere, so they're doing double duty — helping plants grow better while actively drawing carbon down. The new study, published in *Science* on Thursday, was led by Justin Stewart, an evolutionary ecologist at SPUN (Society for the Protection of Underground Networks), and it's a game-changer because for decades we knew these networks existed but had no idea where they were densest, how they were distributed, or how much biomass they actually represented.
The methodology behind this is just as fascinating as the findings — the SPUN team used a combination of literature review, machine learning, and lab testing to create these predictive global maps, pulling from 16,000 geolocated soil samples taken from ecosystems around the world. They even partnered with AMOLF, a research institute in Amsterdam, to develop a robotic camera system that records fungal networks growing over time in the lab, giving them much better estimates of thread widths. The result? The living arbuscular mycorrhizal fungal networks have a total mass of about five times the weight of all humans on Earth. But here's what really got my attention: while wild grasslands hold about 40 percent of the world's arbuscular mycorrhizal biomass, they're among Earth's least protected ecosystems, and grasslands are being converted into farmland at four times the rate of forests. Cropland fungal network densities are about half of what they are in wild ecosystems, and previous research from SPUN found that 90 percent of fungal communities globally are unprotected. Toby Kiers, executive director and co-founder of SPUN, put it perfectly: "This is the moment where we went from knowing that this system exists to really knowing where it is, how dense it is and where it's been."
What's next is going to be wild — the SPUN team will be presenting at COP31 (the United Nations Climate Change Conference) to policymakers about the networks' role in protecting ecosystems and sequestering carbon. Corentin Bisot, an AMOLF biophysicist and co-author, noted that we're still far from having the full "toolbox" to actively increase microbes and fungi in specific areas, and James Bever of the University of Kansas said this study "helps us come to grips with how important these below ground organisms can be to everything that we see above ground." Stewart compared it to the first maps the Spaniards drew of California — which mistakenly presented the state as an island — meaning this is just the first map of fungal networks, and there's plenty more to discover. The study only covers living networks and doesn't include dead fungal networks, which also store carbon and add to total biomass, so there's even more to come.
Source: https://arstechnica.com/science/2026/06/threads-of-underground-fungal-networks-are-long-enough-to-reach-beyond-the-solar-system/