演化生物学家托比·基尔斯（Toby Kiers）深入探讨了地底下的菌根真菌网路如何与植物建立起已有四亿五千万年历史的古老共生关系。地球上超过八成的植物物种依赖这些微观真菌来分解岩石并吸收磷、氮及水分，而植物则将光合作用产生的碳转化为糖分与脂质作为回报。透过开放式的管状网路、分子马达以及水通道蛋白调节的压力，这些没有分隔隔膜的真菌能在同一管道内同时实现双向的物质运输。这个被称为地球循环系统之一的庞大网路，每年能将约一百三十亿吨的二氧化碳封存于土壤深处（相当于全球化石燃料排放量的三分之一），不仅维持了土壤结构与农业粮食生产，还能分解污染物并透过释放孢子促进雨林上空的云层形成。（关键数字：450, 80, 13）
基尔斯的实验室运用经济学与赛局理论的视角，结合萤光量子点与显微成像机器人等先进工具，揭示了这些没有大脑或中枢神经系统的生物如何进行精密的资讯处理与去中心化决策。在这个地下市场中，植物与真菌都能辨别合作伙伴的优劣，并将更多资源分配给提供较高回报的对象；例如，真菌会减少对处于阴影下植物的磷供应，甚至囤积磷或将其跨网路转移至愿意支付更多碳的植物区域以哄抬价格。此外，这种伴随著竞争张力的互利机制也体现在其他共生系统中，如大豆根瘤能侦测固氮菌的产量，并透过切断氧气供应来惩罚未能提供氮肥的欺骗者，而某些不进行光合作用的兰花则演化出直接从真菌网路窃取碳的策略。
为了弥合学术研究与环境保护决策之间的落差，基尔斯于二〇二一年创立了非营利组织「保护地下网路协会」（SPUN），致力于绘制全球菌根真菌的生物多样性图谱并倡导其保育工作。目前地球上有高达五成九的物种生活在地底，但百分之九十的菌根生物多样性热点却位于现有保护区之外，因此该组织正与全球超过八十个国家的科学家合作，利用基因定序与机器学习建立「地下地图集」以协助生态复育。除了气候与保育意义，菌根真菌在单一网路与孢子内同时包含数百个不同细胞核与两套基因组的特性，也彻底挑战了人类对有性生殖与生物个体界线的传统定义，展现出生命在合作与冲突张力中不断创新的复杂交响曲。（关键数字：2021, 59, 90）
Evolutionary biologist Toby Kiers explores how underground mycorrhizal fungal networks have maintained an ancient symbiotic partnership with plants for 450 million years. Over 80% of Earth's plant species rely on these microscopic fungi to break down rocks and absorb phosphorus, nitrogen, and water, while plants reciprocate by supplying carbon in the form of sugars and lipids. Utilizing open-pipe tubular networks, molecular motors, and pressure regulated by aquaporins, these uncompartmentalized fungi simultaneously transport fluids in two opposite directions within the same tube. Acting as one of Earth's circulatory systems, this vast network sequesters roughly 13 billion tons of atmospheric carbon dioxide deep underground each year—equivalent to one-third of global fossil-fuel emissions—while holding soil together, supporting food production, breaking down pollutants, and even aiding cloud formation over rainforests through released spores.
Drawing on economics and game theory alongside tools like fluorescent quantum dots and imaging robots, Kiers's lab reveals how these brainless organisms without a central nervous system perform sophisticated information processing and decentralized decision-making. In this subterranean marketplace, both plants and fungi discriminate between better and worse partners, allocating more resources to those offering higher returns; for instance, fungi withhold phosphorus from shaded plants and hoard or transport phosphorus across their networks to command higher carbon prices. This evolutionary tension between cooperation and competition also appears in other symbioses, such as soybean plants suffocating cheating nitrogen-fixing bacteria inside root nodules by cutting off oxygen, or non-photosynthetic orchids stealing carbon directly from fungal networks.
To bridge the gap between academic research and conservation policy, Kiers founded the nonprofit Society for the Protection of Underground Networks (SPUN) in 2021 to map and protect global mycorrhizal biodiversity. Although 59% of all species on Earth live underground, 90% of mycorrhizal biodiversity hotspots currently lie outside protected areas, prompting SPUN and hundreds of global collaborators to build the digital Underground Atlas using DNA sequencing and machine learning to guide ecosystem restoration. Beyond their ecological role, mycorrhizal fungi harbor two distinct genomes and hundreds of nuclei within a single network and spore, fundamentally challenging conventional definitions of sex and individual organisms while demonstrating how evolutionary tension drives biological complexity and innovation.