Beneath the surface of forests, grasslands and farms across the world, vast fungal webs form underground trading systems to exchange nutrients with plant roots, acting as critical climate regulators as they draw down 13 billion tons of carbon annually.Yet until recently, these “mycorrhizal networks” were greatly underestimated: seen as merely helpful companions to plants rather than one of Earth’s vital circulatory systems.American evolutionary biologist Toby Kiers has now been awarded the Tyler Prize for Environmental Achievement — sometimes called the “Nobel for the environment” — for her work bringing this underground world into focus.By charting the global distribution of mycorrhizal fungi in a worldwide Underground Atlas launched last year, Kiers and her colleagues have helped illuminate below-ground biodiversity — insights that can guide conservation efforts to protect these vast carbon stores.Plants send their excess carbon below ground where mycorrhizal fungi draw down 13.12 billion tons of carbon dioxide — around a third of total emissions from fossil fuels.”I just think about all the ways that soil is used in a negative way — you know, terms like ‘dirtbag,'” the 49-year-old University Research Chair at Vrije Universiteit Amsterdam told AFP in an interview. “Whereas a bag of dirt contains a galaxy!”- Biological marketplace – Kiers began studying fungi at 19, after writing a grant proposal that won her a place on a scientific expedition to Panama’s rainforests, “and I started asking questions about what was happening under these massive trees in this very diverse jungle.”She still vividly recalls the first time she peered through a microscope and saw an arbuscule — the mycorrhizal fungi’s tiny tree-like structure that penetrates plant cells and serves as the site of nutrient exchange — which she described as “so beautiful.”In 2011, Kiers published a landmark paper in Science showing that mycorrhizal fungi behave like shrewd traders in a “biological marketplace,” making decisions based on supply and demand. With filaments thinner than hair, fungi deliver phosphorus and nitrogen to plants in exchange for sugars and fats derived from carbon.Using lab experiments her team demonstrated that fungi actively move phosphorus from areas of abundance to areas of scarcity — and secure more carbon in return by exploiting those imbalances. Plants, in other words, are willing to pay a higher “price” for what they lack.The fungi can even hoard resources to drive up demand, displaying behavior that echoes the tactics of Wall Street traders. The fact that all this happens without a brain or central nervous system raises a deeper question: how fungi process information at all — and whether electrical signals moving through their networks hold the answer.- Debt of gratitude – More recently, Kiers and her colleagues have pushed the field further with two Nature papers that make this hidden world newly visible.One unveiled a robotic imaging system that lets scientists watch fungal networks grow, branch and redirect resources in real time; the other mapped where different species are found across the globe.That global analysis delivered a sobering result: most hotspots of underground fungal diversity lie outside ecologically protected areas.With fungi largely overlooked by conservation frameworks, Kiers co-founded the Society for the Protection of Underground Networks (SPUN) to map fungal biodiversity — and argue for its protection.To coincide with the prize, which comes with a $250,000 award, SPUN is this week launching an “Underground Advocates” program to train scientists in the legal tools they need to protect fungal biodiversity.Her aim, she says, is to get people to flip how people think about life on Earth — from the surface down. “Life as we know it exists because of fungi,” she said, explaining that the algal ancestors of modern land plants lacked complex roots, and that a partnership with fungi enabled them to colonize terrestrial environments.

US President Donald Trump warned of unspecified “very strong action” if Iranian authorities go ahead with threatened hangings of some protesters, with Tehran calling American warnings a “pretext for military intervention”.International outrage has built over the crackdown that a rights group said has likely killed thousands during protests posing one of the biggest challenges yet to Iran’s clerical leadership.Iran’s UN mission posted a statement on X, vowing that Washington’s “playbook” would “fail again”.”US fantasies and policy toward Iran are rooted in regime change, with sanctions, threats, engineered unrest, and chaos serving as the modus operandi to manufacture a pretext for military intervention,” the post said.  Iranian authorities have insisted they had regained control of the country after successive nights of mass protests nationwide since.Rights groups accuse the government of fatally shooting protesters and masking the scale of the crackdown with an internet blackout that has now surpassed the five-day mark.New videos on social media, with locations verified by AFP, showed bodies lined up in the Kahrizak morgue just south of the Iranian capital, with the corpses wrapped in black bags and distraught relatives searching for loved ones.Trump — who earlier told the protesters in Iran that “help is on its way” — said Tuesday in a CBS News interview that the United States would act if Iran began hanging protesters.Tehran prosecutors have said Iranian authorities would press capital charges of “moharebeh”, or “waging war against God”, against some suspects arrested over recent demonstrations.”We will take very strong action if they do such a thing,” said the American leader, who has repeatedly threatened Iran with military intervention.”When they start killing thousands of people — and now you’re telling me about hanging. We’ll see how that’s going to work out for them,” Trump said.The US State Department on its Farsi language X account said 26-year-old protestor Erfan Soltani had been sentenced to be executed on Wednesday. “Erfan is the first protester to be sentenced to death, but he won’t be the last,” the State Department said, adding more than 10,600 Iranians had been arrested. Rights group Amnesty International called on Iran to immediately halt all executions, including Soltani’s.Trump urged on his Truth Social platform for Iranians to “KEEP PROTESTING”, adding: “I have cancelled all meetings with Iranian Officials until the senseless killing of protesters STOPS. HELP IS ON ITS WAY.”It was not immediately clear what meetings he was referring to or what the nature of the help would be. – ‘Rising casualties’ -European nations also signalled their anger over the crackdown, with France, Germany and the United Kingdom among the countries that summoned their Iranian ambassadors, as did the European Union. “The rising number of casualties in Iran is horrifying,” said EU chief Ursula von der Leyen, vowing further sanctions against those responsible.Norway-based NGO Iran Human Rights said it had confirmed 734 people killed during the protests, including nine minors, but warned the death toll was likely far higher.”The real number of those killed is likely in the thousands,” IHR’s director Mahmood Amiry-Moghaddam said.Iranian state media has said dozens of members of the security forces have been killed, with their funerals turning into large pro-government rallies. Authorities in Tehran have announced a mass funeral ceremony in the capital on Wednesday for the “martyrs” of recent days.Amir, an Iraqi computer scientist, returned to Baghdad on Monday and described dramatic scenes in Tehran.”On Thursday night, my friends and I saw protesters in Tehran’s Sarsabz neighbourhood amid a heavy military presence. The police were firing rubber bullets,” he told AFP in Iraq.Reza Pahlavi, the US-based son of Iran’s ousted shah, called on the military to stop suppressing protests. “You are the national military of Iran, not the military of the Islamic Republic,” he said in a statement. – ‘Serious challenge -The government on Monday sought to regain control of the streets with mass nationwide rallies that supreme leader Ayatollah Ali Khamenei hailed as proof that the protest movement was defeated, calling them a “warning” to the United States. In power since 1989 and now aged 86, Khamenei has faced significant challenges, most recently the 12-day war in June against Israel, which forced him to go into hiding.Analysts have cautioned that it is premature to predict the immediate demise of the theocratic system, pointing to the repressive levers the leadership controls, including the Revolutionary Guard Corps, which is charged with safeguarding the Islamic revolution.Nicole Grajewski, professor at the Sciences Po Centre for International Studies, told AFP the protests represented a “serious challenge” to the Islamic republic, but it was unclear if they would unseat the leadership, pointing to “the sheer depth and resilience of Iran’s repressive apparatus”.