Source: Bioneers | Talk by Merlin Sheldrake
Before plants evolved their own root systems, fungi provided the connection to the soil that enabled plants to move from water onto land. These underground networks remain crucial to plants’ survival, exchanging nutrients, forming relationships with microbes, and funneling billions of tons of carbon dioxide into the soil. They are also vast, with the mycorrhizal fungal mycelium in the top 10 centimeters of soil extending more than 450 quadrillion kilometers. Despite this, they represent a global blindspot. Because they are underground and unseen, 90% of mycorrhizal fungal hotspots currently fall outside protected areas. This is a problem not only for the fungi but all the organisms and ecosystems that depend on them. In the following edited transcript of a Bioneers keynote address, biologist and bestselling author Merlin Sheldrake talks about the vital work of the Society for the Protection of Underground Networks (SPUN) to map and protect these fungal networks and preserve this “ancient library of solutions.”
I’m going to talk about fungi. Fungi are ecosystem engineers that underwrite the regenerative capacity of the living world. There are lots of ways to be a fungus. I’m going to talk about a specific group of fungi called mycorrhizal fungi.
Mycorrhizal fungi form intimate and ancient relationships with plants. I’m going to ask how we can nourish generative relationships with mycorrhizal fungi to support the flourishing of life on Earth and help address the coupled crises of climate change and biodiversity loss.
Almost all plants depend on mycorrhizal fungi, and these are fungi that form mycelial networks — which are branching, fusing networks of tubular cells. These fungi are brilliant. They’re chemical wizards. They’re brilliant navigators in the wild, wet world of the soil. They’re able to grow and remodel their bodies and forage using their chemical ingenuity for nutrients — nutrients that plants need, like nitrogen and phosphorous. They acquire these nutrients, and they supply them to their plant partners. The plant partners, in exchange, provide the fungi with things that the fungi need to grow — energy-containing carbon compounds like sugars and fats that the plants have made in photosynthesis.
This relationship is one of the living world’s great intimacies. It is an astonishing way that organisms can come together, extend their reach, and make things possible that wouldn’t otherwise be possible. These are really the roots of life on land. Plants can only make it out of water onto the land with the help of their fungal associates, who have behaved as their root systems for tens of millions of years until plants could evolve their own roots.
These are sophisticated relationships. At any one moment, a mycorrhizal fungus will be remodeling itself to explore the soil, one of the most complex habitats on the planet. It will be doing crazy things with its metabolism to forage and acquire nutrients. It will be forming relationships with crowds of microbes across its network. It will be diverting nutrients around its networks, circulating them in just the right way to enable it to trade with its plant partners. It must be integrating information across an immense number of nodes, which at any one moment can be strung between multiple plants and sprawled over meters.
The influence of these quadrillions of trading decisions spills out over land masses and continents. A recent study that Toby [Kiers, Ph.D., Professor of Evolutionary Biology and Executive Director and Chief Scientist at SPUN] and I are part of found that mycorrhizal fungi funnel around 13 billion tons of CO2 into the soil every year. That’s as much as a third of the total CO2 emissions produced by the burning of fossil fuels every year. It’s a significant amount of carbon. They stabilize this carbon in the soil and power soil food webs, which contain over half of all species on the planet.
Globally, the total length of mycorrhizal fungal mycelium in the top ten centimeters of soil is more than 450 quadrillion kilometers, which is over half the width of the galaxy. These organisms are stationed at a vital point in global carbon and nutrient cycles, and they make up one of the planet’s circulatory systems, an ancient life support system that easily qualifies as one of the wonders of the living world.
However, despite their roles in supporting plant biodiversity and regulating the Earth’s nutrient cycles and climates, mycorrhizal fungi are a global blind spot. They are largely absent from climate change agendas, conservation strategies, restoration strategies, agriculture, and forestry. This is a problem.
It’s a problem first because mycorrhizal fungi lie at the base of the food web that sustains much of life on Earth and is a key lever in planetary ecology. Yet hardly anyone touches this lever. It would be like trying to perform life-saving surgery without considering our bodies’ circulatory systems.
It’s a problem for another reason. What we are blind to, we tend to destroy. The destruction of underground ecosystems accelerates climate change by causing diversity loss. What’s more, when we disrupt these communities, we destroy an ancient library of solutions that fungi have evolved. We have no idea how many of these solutions might prove vital to life on Earth moving forward. When mycorrhizal fungi suffer, so do the organisms and ecosystems that depend on them.
So, back to this question: How can we nourish generative relationships with these ancient life support systems to support the flourishing of life on Earth, and respond to climate and biodiversity crises? I’m going to describe two projects that I work on with Toby.
The first is this grand, very big, zoomed-out perspective. It’s the Society for the Protection of Underground Networks, or SPUN. SPUN is trying to answer this question by taking a global perspective, using huge datasets to map the planet’s mycorrhizal communities and advocate for their protection.
The second approach zooms all the way in. We use advanced microscopy, robotics, and machine learning tools to look inside mycorrhizal fungi to try to decode the flows and behavioral dialects of these living, sensing networks. In both of these projects, we are seeking partners and funders, collaborators, and resources, so if you feel moved, please do get in touch. You can find a place to do it on my website.
There are many threats to underground ecosystems, despite the fact that we think about them less than we should—deforestation, desertification, over-application of industrial agricultural chemicals like fungicides and fertilizers, over-plowing—the list goes on. The result of all of this combination is that, based on current trends, 90% of the Earth’s soils will be degraded by 2050.
SPUN is an organization working to map and protect mycorrhizal fungal communities, and in doing so, find ways to harness their power to help mitigate and adapt to climate and biodiversity crises. Why map? One of the reasons is that we know very, very little about who lives where underground. We have maps of ocean currents, we have maps of global vegetation, we have maps of global climate. We don’t have maps of mycorrhizal fungal communities. This limits our ability to monitor and protect these key underground ecosystems. It limits our ability to work out which are the most important underground ecosystems to monitor and protect.
SPUN is working to make reliable maps that can inform decision-makers and support legal actions to protect land from ecocidal exploitation. To do so, we are supporting the creation of a decentralized network of scientists around the world and funding researchers in local communities to answer mycorrhizal questions in their places, in their homes, and in the ecosystems that they care about. All of this data comes back to feed the very big models that we’re making to build the global maps.
We have so many wildly enthusiastic mycorrhizal researchers coming out of the woodwork. We’re building capacity for mycorrhizal research all over the world, especially in places where this research has happened much less. There are researchers in the Ivory Coast studying cacao plantations, and researchers in Mexico using these mycorrhizal diversity maps to engage local politicians to protect water sources. There are people comparing the communities in humid and dry forests in Madagascar. It’s hugely exciting. We are inundated with enthusiasm and requests, and actually really struggling to keep up. This is hugely gratifying.
Usually, if you were to make a map of global biodiversity, you would just look at the organisms living above ground, and you would find diversity was concentrated around the tropical regions and fades out as you move toward the poles. But that’s not the case here. There are mismatches between biodiversity above ground and below ground, and this is one of the reasons why it’s so important to take these below-ground communities into account as we try to work out who lives where and what everyone’s doing. Building these maps of mycorrhizal fungal communities can help us to approach aboveground life from the perspective of belowground organisms.
Why does this matter? We think that these maps can help inform climate change strategies, restoration practices, land management, and legal actions. These maps reveal that over 90% of mycorrhizal fungal hotspots are currently falling outside protected areas, which means that they’re at immediate risk. We’re trying to quantify these threats.
We have a map that shows what we call an integrated threat index, combining different kinds of threats to mycorrhizal fungal ecosystems, mycorrhizal fungal communities, and underground ecosystems. We can integrate the threat to mycorrhizal fungal communities with mycorrhizal fungal diversity. This kind of map can empower decision-makers and form the basis for tools to support mycorrhizal fungal life and the processes that they oversee.
One project that I’m really excited about right now is a collaboration to test the application of this kind of fungal dataset in legal actions. We’re working together with the More Than Human Rights Collective, the Fungi Foundation, and the Sarayaku people of Amazonian Ecuador. With the Sarayaku people, we’re going to visit the territory to map the mycorrhizal communities and provide them with these datasets, which they can then use in their ongoing legal battles with the Ecuadorian government to make sure that the underground communities are protected. So many of the threats that these ecosystems face are from mining, which explicitly destroys the underground.
We’re really thrilled at how this is unfolding. We’re thrilled about these coalitions that we’re building and where this can go.
Watch Merlin Sheldrake’s full talk at Bioneers here — How Fungi Make our Worlds.