Unveiling the Subterranean Library of Wonders: Fungi's Hidden Role in Carbon Capture

One has to descend a couple of flights of steps beneath the London suburb of Kew Gardens, whose greenhouse-enshrouded tropical canopy can be heard overhead like water dripping on a forest floor. This isn’t a museum’s hidden basement, but an endlessly branching subterranean treasure trove. Its gold is contained within flowers — but not the colourful, showy blossoms. These treasures are the tiny, often overlooked, mushrooms. The fungi kept in the Kew culture collection could hold the key to the future of the planet.

The Fungarium: Earth's Unsung Heroes Catalogued

Underneath the laboratory, bordering the garden, is the fungarium, home to 1.3 million specimens, gathered in unassuming green cardboard boxes. The species in each box represent a chapter in a library of a billion fungi; the fruiting bodies in them release spores into the air. Its collections represent half the known species of fungi. Coming here is like entering an early NASA facility or a Smithsonian museum – you can see a massive reference set for the diversity of a life form here.

Fungi: From Underappreciated to Understudy

It would be fair to say that fungi played a supporting role in environmental consciousness until a staffing reorganisation in August 2014 tossed a former tropical plants researcher called Lee Davies into the fungarium, where the peculiar charms of the planet’s fungal biomass would become impossible to ignore. In the years since, there’s been no shortage of cultural and scientific signposts along the winding path to rehabilitation.

The Carbon Capture Conundrum

But perhaps one of fungi’s most vital functions is in their niche as carbon sequestering organisms. The soil, the greatest terrestrial carbon store, is made more effective with fungi. The mycologist Laura Martinez-Suz leads research on the role that fungi play in soils carbon-sequestring function. Mycorrhizal fungi form symbiotic relationships with plant roots, their networks transporting nutrients and carbon.

Fungi and Forest Restoration Efforts

The carbon sequestration role of tree-planting schemes might also depend on keeping these mycorrhizal networks intact. New vegetation can damage stocks of soil carbon. Either way, taking fungi into account in ecological restoration and management plans will be increasingly important.

The Threat of Nitrogen Pollution

There are still hurdles for fungus to clear, with nitrogen pollution from burning fossil fuels and tilling crops changing the balance of fungi in the soil, and thus potentially reducing its ability to sequester carbon. Even so, as Sato’s work shows, reducing nitrogen pollution can reverse some of the damage. If we want nature to thrive, we need to allow ecosystems to thrive.

Discoveries Await: The Fungarium's Future Endeavors

It is a daunting task: we are thought to have discovered a mere 10 per cent of the total number of fungi species. The fungarium at Kew is expanding every month, and the collection is still taking in material from keen amateur mycologists across the world. ‘Fascination with these organisms is shared globally,’ said Andy Day.

Exploring the Essence of FOSSIL

When I set out to study linkages of these signals through fungi in global ecologies, the spotlight usually falls on the antagonists to their benefits – fossil burning, specifically. Burning fossils contributes to nitrogen pollution in ways that disrupt the fungal soil balances that allow sequestration of carbon. That we still rely so much on such energy is a threat to the fungal fabric of life and a timely call to find more sustainable approaches.

Every time we better understand the symbiotic relationships that support life on Earth, we perhaps tell a story as beautiful as that of the fungarium at Kew Gardens. Not just a story of scientific discovery, but of everything being connected. The fungi are there, looking after the plants even as this invisible kingdom is the most important steward of carbon remaining on the planet. In tackling the climate crisis, there might be more answers we can find under our feet.