By building a robot that tracks over half a million fungal ’roadways’ simultaneously, Tom Shimizu (Vrije Universiteit Amsterdam/AMOLF), Toby Kiers (Vrije Universiteit Amsterdam/Society for the Protection of Underground Networks), Howard Stone (Princeton) and collaborators succeeded in mapping and tracking these nutrient-exchange networks that help regulate earth’s ecosystems and carbon cycles. With atmospheric CO2 levels rising, the collected data is becoming increasingly important. Their study was published in Nature.
More than 80% of plant species form symbiotic partnerships with mycorrhizal fungi, exchanging carbon for essential nutrients like phosphorus and nitrogen. These networks play a crucial role in storing carbon underground, drawing down an estimated 13 billion tons of CO2 each year—equivalent to one-third of global energy-related emissions. Despite their importance, scientists had not fully understood how these organisms construct such vast and efficient underground trade routes—until now.
How fungi build and optimize their networks
The international team of 28 researchers discovered that fungi grow in a wave-like pattern, moving carbon outward from plant roots. To support this growth, they manage a system of two-way ‘traffic’, controlling flow speed and the width of the fungal highway based on need.
The researchers also found that fungi send out special microscopic ‘pathfinder’ branches to explore new areas, prioritizing long-term trade potential over short-term growth. This strategic behavior prevents wasteful overbuilding and ensures efficient nutrient exchange between fungi and plants.
Unprecedented precision using robotics
These insights were made possible by a custom-built imaging robot designed and fabricated at AMOLF. The robot tracked the growth of many fungal networks simultaneously over three years, capturing data that would have taken a human researcher a century to collect.
“We’re trying to figure out how these ‘brainless’ microorganisms manage to control their trade behaviors,” says Shimizu. “We discovered here that fungi constantly refine their trade routes, adding loops that shorten paths to and from plants and boost efficient nutrient delivery.” Using advanced imaging techniques, researchers at AMOLF obtained and analyzed live footage of nutrient flows throughout the system, resembling two-way traffic on a busy road.
What fungi can teach us about supply chains
The research highlights how fungi have evolved highly efficient distribution strategies; systems that humans can learn from.
“Humans increasingly rely on AI algorithms to build supply chains that are efficient and resilient. Yet fungi have been solving these problems for more than 450 million years. This is the kind of research that keeps you up at night because these fungi are such important underground circulatory systems for nutrients and carbon,” says Kiers.
Implications for climate and carbon storage
With rising atmospheric CO2 levels, understanding fungal networks is more critical than ever. The scientists aim to explore what factors trigger fungi to store more carbon underground, potentially offering new strategies for climate mitigation. “Understanding how these fungal networks adjust internal flows and resource trading to build supply chains in response to environmental stimuli will be an important direction for future research,” says Stone.
The team is now in the final stages of building a new robot that will increase data collection by a further 10x, allowing them to explore how fungal networks respond to rapid environmental change, including increases in disturbance and rising temperatures.