研究重点由 Van Nuland 的模型研究拉到全球尺度：其Nature（2025）模型以25,000份土壤样本训练机器学习，产生超过28亿条真菌DNA序列，预测出高多样性且罕见的 mycorrhizal hot spots，阿拉斯加北坡因此被列为重点区。据估计，mycorrhizal 菌每年可影响超过全球碳排放三分之一，分别约3.93十亿吨（arbuscular）与9.07十亿吨（ectomycorrhizal），合计约13十亿吨；若以碳储存能力比较，北极苔原上层3米土壤约锁存1兆公吨碳，约为整个亚马逊流域的十倍。团队同时指出，未来每年不足10%的预测 hot spots 在保护区内，而受控条件包括变暖、湿度上升、野火增加、永久冻土退化使该区仍高度脆弱。
在阿拉斯加北坡四日里程中，研究团队每站采9个土芯、共60站、540份土样，最后以南下至 Brooks Range 的42??站梯度完成，并于2025年11月回报初步结果：每站平均约75种 ectomycorrhizal 菌，354种中有253种未被记录，比例约71.2%；约四分之三在其他地区未见，显示可能高度地方性。样点构成由北向南明显转变，符合高山隔离与海岸夹挤造成的长期共进化。研究者警告，未来冻土融化将释放千年尺度封存碳，某些菌种可能成为“碳守门人”或“碳泄漏源”，决定阿拉斯加是温室气体汇还是源；SPUN正计划扩展至多国站点（遍及79国），并在2026年再次回到 Deadhorse 量测碳通量，以补足保育与气候模型的关键缺口。
In a June 2025 Alaska expedition, Michael Van Nuland and the SPUN team drove the 414-mile Dalton Highway (built in 1974) on a four-day, 150-mile tundra mission. The landscape appeared sparsely vegetated above ground but functioned as habitat for seasonal caribou, grizzlies, muskox, and about 200 bird species. Underground, mycorrhizal fungal networks linked plant roots and moved nutrients and water. These networks are made of fine hyphae about 5 micrometers wide, roughly one-tenth the width of a human hair, and are increasingly interpreted as active organisms that regulate ecosystem flows rather than passive root accessories.
The study scaled from these observations to global prediction: a Nature (2025) model trained on 25,000 soil samples using machine learning generated over 2.8 billion fungal DNA sequences and identified potential mycorrhizal hot spots with high diversity and rarity, making the Alaskan North Slope a target site. Current estimates attribute 3.93 billion tons of carbon storage to arbuscular fungi and 9.07 billion tons to ectomycorrhizal fungi each year, together about 36% of global annual CO2 emissions. Permafrost in the top three meters across the Arctic stores about 1 trillion metric tons of carbon—about 10 times the carbon in the whole Amazon basin. Yet fewer than 10% of SPUN-predicted hot spots fall in protected land, while warming, higher moisture, increasing wildfire risk, and permafrost thaw increasingly endanger them.
The expedition collected 9 cores per site across 60 sites (540 samples total) and recorded roughly 75 ectomycorrhizal species per site on average. Of 354 species identified, 253 were previously unknown, and about three-quarters have not been found elsewhere, indicating strong endemism likely shaped by mountain barriers and long isolation. Species composition shifted strongly from north to south, reinforcing the uniqueness of this region. As thaw deepens, long-frozen carbon and microbial decomposition may alter fluxes: some fungi preserve carbon efficiently while others release more greenhouse gases. The team reported that such outcomes determine whether warming Arctic soil becomes a carbon sink or source, so identifying species traits is central to climate risk assessment. In summer 2026 they plan to return to Deadhorse to measure carbon flux and improve protection priorities globally through continued sampling across 79 countries.