Scientists build robot to track plant-fungal trade networks, revealing nature’s underground supply chains

By tracking half a million fungal highways and the traffic flows within them, researchers describe how plants and symbiotic fungi build efficient supply chains

The team built an imaging robot that allowed them to gather 100 years’ worth of microscopy data in under 3 years

Work advances our understanding of how fungi move billions of tons of CO₂ into underground ecosystems each year

New research published in the science journal Nature used advanced robotics to track the hyper-efficient supply chains formed between plants and mycorrhizal fungi as they trade carbon and nutrients across the complex, living networks that help regulate the Earth’s atmosphere and ecosystems.

Understanding plant-fungal trade is urgent because these fungal networks draw down around 13 billion tons of CO2 per year into the soil - equivalent to ~1/3 of global energy-related emissions. More than 80% of plant species on Earth form partnerships with mycorrhizal fungi, in which phosphorus and nitrogen collected by fungi is exchanged for plant carbon. Despite their global importance, scientists did not understand how these brainless organisms construct expansive and efficient supply chains across their underground networks.  

Using a custom-built imaging robot, the international research team of 28 scientists discovered that the fungi construct a lace-like mycelial network that moves carbon outward from plant roots in a wave-like formation. To support this growth, fungi move resources to-and-from plant roots using a system of two-way traffic, controlling flow speed and width of these fungal highways as needed. To seek further resources, the fungi deployed special growing branches as microscopic ‘pathfinders’ to explore new territory, appearing to favor trade opportunities with future plant partners over short-term growth within immediate surroundings. The researchers describe how these behaviors appear to be coordinated by simple, local “rules” that prevent the fungus from “over-building” and define a unique ‘travelling wave strategy’ for growth, resource exploration, and trade.