Underland

by Robert Macfarlane

‘You can put rhizotrons into the ground to look at root growth,’ Merlin says, ‘but those don’t really give you the fungi because they’re too fine. You can do below-ground laser scanning but, again, that’s too crude for the fungal networks.’

  I am reminded once more of how resistant the underland remains to our usual forms of seeing; how it still hides so much from us, even in our age of hyper-visibility and ultra-scrutiny. Just a few inches of soil is enough to keep startling secrets, hold astonishing cargo: an eighth of the world’s total biomass comprises bacteria that live below ground, and a further quarter is of fungal origin.

  ‘We know the network is there,’ Merlin says, ‘but it’s so effortful to track it. So we have to look for clues to the labyrinth – find clever means of following its paths.’

  I kneel beside him. I can see dozens of insects just in this small area, the names of most of which I do not know: gleaming spiders and red-bronze beetles battling over the leaves, a woodlouse curled up into a sphere, a green threadworm writhing through the humus.

  ‘It’s roiling with life,’ I say to Merlin.

  ‘That’s just the visible life. Hyphae will be growing into the decomposing matter of this half-rotting leaf,’ says Merlin, ‘into those rotting logs and those rotting twigs, and then you’ll have the mycorrhizal fungi whose hyphae grow into hot spots – all of them frothing and tangling and fusing, making a network that’s connecting holly to holly but also to this beech, and to a seedling of something else over there, layering and layering and layering – until, well, it blows your computational brain!’

  As Merlin speaks I feel a quick, eerie sense of the world shifting irreversibly around me. Ground shivering beneath feet, knees, skin. If only your mind were a slightly greener thing, we’d drown you in meaning . . . I glance down, try to trance the soil into transparency such that I can see its hidden infrastructure: millions of fungal skeins suspended between tapering tree roots, their prolific liaisons creating a gossamer web at least as intricate as the cables and fibres that hang beneath our cities. What’s the haunting phrase I’ve heard used to describe the realm of fungi? The kingdom of the grey. It speaks of fungi’s utter otherness – the challenges they issue to our usual models of time, space and species.

  ‘You look at the network,’ says Merlin, ‘and then it starts to look back at you.’

  ~

  In the underland of the hardwood forests of Oregon’s Blue Mountains there exists a honey fungus, Armillaria solidipes, that is two and a half miles in extent at its widest point, and covers a total lateral area of almost four square miles. The blue whale is to this honey fungus as an ant is to us. It is a deeply mysterious organism: the largest in the world that we know of, and one of the oldest. The best guess that US Forest Service scientists have been able to offer for the honey fungus’s age is between 1,900 and 8,650 years old. The fungus expresses itself above ground as mushrooms with white-flecked stems rising to tawny, gill-frilled cups. Below ground, where its true extent lies, Armillaria solidipes moves as rhizomorphs resembling black bootlaces, out of which reach the hyphal fingers of its mycelium, spreading in search both of new hosts which they might kill, and the mycelia of other parts of the colony with which they might fuse.

  All taxonomies crumble, but fungi leave many of our fundamental categories in ruin. Fungi thwart our usual senses of what is whole and singular, of what defines an organism, and of what descent or inheritance means. They do strange things to time, because it is not easy to say where a fungus ends or begins, when it is born or when it dies. To fungi, our world of light and air is their underland, into which they tentatively ascend here and there, now and then.

  Fungi were among the first organisms to return to the blast zone around the impact point in Hiroshima, the point from which the mushroom cloud had risen. After Hiroshima, too, images of the mushroom cloud began to appear ubiquitously in media and culture – the fruiting bodies of a new global anxiety. Scientists working in Chernobyl after the disaster there were surprised to discover fine threads of melanized fungi lacing the distressed concrete of the reactor itself, where radiation levels were over 500 times higher than in the normal environment. They were even more surprised to work out that the fungi were actively thriving due to the high levels of ionizing radiation: that they benefited from this usually lethal gale, increasing their biomass by processing it in some way. Ecologists in the US seeking to understand how American trees will respond to the stress of climate change have begun to focus on the presence of soil fungi as a key indicator of future forest resilience. Recent studies suggest that well-developed fungal networks will enable forests to adapt faster at larger scales to the changing conditions of the Anthropocene.

  ‘Learning to see mosses is more like listening than looking,’ writes the ethnobotanist Robin Wall Kimmerer; ‘mosses . . . issue an invitation to dwell for a time right at the limits of ordinary perception.’ Learning to see fungi seems even harder – requiring senses and technologies that we have yet to develop. Even to try and think with or as fungi is valuable, though, drawing us as it does towards lifeways that are instructively beyond our ken.

  Certainly, orthodox ‘Western’ understandings of nature feel inadequate to the kinds of world-making that fungi perform. As our historical narratives of progress have come to be questioned, so the notion of history itself has become remodelled. History no longer feels figurable as a forwards-flighting arrow or a self-intersecting spiral; better, perhaps, seen as a network branching and conjoining in many directions. Nature, too, seems increasingly better understood in fungal terms: not as a single gleaming snow-peak or tumbling river in which we might find redemption, nor as a diorama that we deplore or adore from a distance – but rather as an assemblage of entanglements of which we are messily part. We are coming to understand our bodies as habitats for hundreds of species of which Homo sapiens is only one, our guts as jungles of bacterial flora, our skins as blooming fantastically with fungi.

  Yes, we are beginning to encounter ourselves – not always comfortably or pleasantly – as multi-species beings already partaking in timescales that are fabulously more complex than the onwards-driving version of history many of us still imagine ourselves to inhabit. The work of the radical biologist Lynn Margulis and others has shown humans to be not solitary beings, but what Margulis memorably calls ‘holobionts’ – collaborative compound organisms, ecological units ‘consisting of trillions of bacteria, viruses and fungi that coordinate the task of living together and sharing a common life’, in the philosopher Glenn Albrecht’s phrase.

  Little of this thinking is new, however, when viewed from the perspective of animist traditions of indigenous peoples. The fungal forest that science had revealed to Merlin and that Merlin was revealing to me – a forest of arborescent connections and profuse intercommunication – seemed merely to provide a materialist evidence-base for what the cultures of forest-dwelling peoples have known for thousands of years. Again and again within such societies, the jungle or woodland is figured as aware, conjoined and conversational. ‘To dwellers in a wood almost every species of tree has its voice as well as its feature,’ wrote Thomas Hardy in Under the Greenwood Tree. The anthropologist Richard Nelson describes how the Koyukon people of the forested interior of what we now call Alaska ‘live in a world that watches, in a forest of eyes. A person moving through nature – however wild, remote . . . is never truly alone. The surroundings are aware, sensate, personified. They feel.’ In such a vibrant environment, loneliness is placed in solitary confinement.

  There in the grove with Merlin, I recall Kimmerer, Hardy and Nelson, and feel a sudden, angry impatience with modern science for presenting as revelation what indigenous societies take to be self-evident. I remember Ursula Le Guin’s angrily political novel, set on a forest planet in which woodland beings known as the Athsheans are able to transmit messages remotely between one another, signalling through the medium of trees. On Athshe – until the arrival of colonists committed to the planet’s exploitation
– the realm of mind is integrated into the community of the trees, and ‘the word for world is forest’.

  ~

  Four hours into our walk and Epping is playing the usual tricks of forests: disorientation, echoes, a refusal to repeat itself. Often I think we are reversing a path we have already walked, only to find ourselves led into a new area of heath, an unfamiliar grove or thicket. We kick up invisible spores spread by last autumn’s fungi, breathing them into our lungs. We wander so far north that we run out of forest, rebound off the M25, hop a barbed-wire fence, and come to rest in a field that looks as if it is privately owned. We aren’t lost, exactly, but we want to know where the forest widens again.

  So I use my phone to summon the satellite network, and pull up a hybrid map of the forest. Sixty-three distinct chemical elements including rare earth metals and minerals mined mostly in China interact within the casing of my device. A blue lanthium dot pulses our location. I pinch and splay the screen to get the right scale. The map shows that the forest flares green to the south-west, so that is where we head – crossing a busy road and then pushing deeper into the trees until we can hardly hear car noise.

  In a dry part of the forest, on rising ground, with old pines, beeches and an understorey of holly, we stop to eat and drink, sitting among snaking pine roots. I tell Merlin about Boulby Mine, about the dark-matter lab, the halite tunnels, the men at the face, the geologists sending their probes forwards, falling back from the face, questing in the dark.

  ‘It’s so similar to the way fungi work,’ Merlin says, ‘always prospecting for the most resource-rich or beneficial region, pushing on where they sense benefit. They fan out and if they find a decent seam in one place they die back from the poor areas and concentrate their efforts elsewhere.’ He takes my notebook and pen, and draws a diagram of the classic hyphal structure: a branching fan in which it is hard to speak of a main or originary stem, only of shoots and offshoots.

  In the second year of his doctorate, Merlin went to conduct fieldwork in the Central American jungle – on Barro Colorado Island, located in the man-made Gatun Lake of the Panama Canal.

  ‘I was so ready to leave the lab for the jungle,’ he says. ‘In a molecular biology lab you’re in near-total control of these little worlds; you’re the giant puppet master making your subject dance to your tune. In the field, though, you’re inside your subject matter and the power relation is totally different.’

  On the island Merlin joined a community of field biologists, all of them dancing to the tune of the jungle. He operated under the watchful eye of a grizzled evolutionary biologist called Egbert Giles Leigh Jr, who lived on the base and received new arrivals in his book-lined study, where he played Beethoven on his gramophone and drank whisky-no-ice-no-mixer. This benevolent Kurtz was the island’s archive and overseer.

  Some of the science undertaken on the island was methodologically high risk. There was a young American scientist researching what Merlin called ‘the Drunken Monkey Hypothesis’. Her plan was to collect monkey urine after the monkeys had feasted on fermenting fruit, and to assess the urine for intoxication levels. The problem was that the monkeys tended to urinate from high up in the trees. So she developed a wide-mouthed funnel with which to catch the falling liquid.

  ‘Just to be clear,’ I ask, ‘she was getting drunken monkeys to pee down a funnel from the canopy?’

  ‘Absolutely – and that was very laborious work. She also seemed, you might say, an unlikely candidate for this particular kind of research.’

  Then there was someone nicknamed ‘the Bumblebee Guy’, who trapped bumblebees and stuck adhesive radio-trackers to their abdomens in order to be able to map their feeding and pollinating patterns of movement.

  ‘But the adhesive didn’t stick so well, because the bees were hairy and the air was humid,’ says Merlin, ‘so he then had to capture his bees and shave tiny patches of their abdomens, in order to stick the trackers on more reliably.’

  There was also ‘the Lightning Guy’, who studied the effects of lightning strikes on below-ground ecologies, and tried to induce site-specific strikes by firing crossbow bolts trailing copper wire at storm clouds.

  ‘Sounds like a carnival out there,’ I say.

  ‘Basically, what you quickly discovered,’ Merlin says, ‘was that if your experiment wasn’t good enough, the jungle would screw it up.’

  During his second season on the island, Merlin became interested in a type of plants called ‘mycoheterotrophs’ – ‘mycohets’ for short. Mycohets are plants that lack chlorophyll and thus are unable to photosynthesize. As such they are entirely reliant on the fungal network for their provision of carbon. Some are white, some tinged lilac or violet.

  ‘These little ghosts plug into the fungal network,’ Merlin explains, ‘and somehow derive everything from it without paying anything back, at least in the usual coin. They don’t play by the normal rules of symbiosis – but we can’t prove they’re parasites. You could imagine them as the hackers of the wood wide web.’

  Merlin focused on a genus of mycohets called the Voyria, a group of gentians known as ‘ghost plants’, the flowers of which studded the jungle floor on Barro Colorado Island like pale purple stars. Working with local villagers, he carried out a painstaking census of the soil in a series of plots, sampling and sequencing the DNA of hundreds of root samples taken both from green plants and the Voyria. The census allowed him to determine what species of fungi were connecting with which plants – and thereby to make an unprecedentedly detailed map of the jungle’s social network.

  ‘I only stumbled across the importance of Voyria by accident,’ he says, ‘wandering around one day looking for something else, when I realized that they had almost vanished from a plot from which we’d increased the phosphorus input. That’s how my breakthrough began. Science is full of this stuff: full of happenstance and stumbles and getting knackered and crazy in the field or the lab. It’s so weird to me how science always presents its knowledge as clean.’

  A green woodpecker yaffles in the distance.

  ‘I have this plan,’ Merlin says, ‘that for each formal scientific paper I ever publish I will also write its dark twin, its underground mirror-piece – the true story of how the data for that cool, tidy hypothesis-evidence-proof paper actually got acquired. I want to write about the happenstance and the shaved bumblebees and the pissing monkeys and the drunken conversations and the fuck-ups that actually bring science into being. This is the frothy, mad network that underlies and interconnects all scientific knowledge – but about which we so rarely say anything.’

  ~

  Late in the day we come to a lake in the woods, where a mudbank slopes into shallow water.

  Fish sup in the shadows. Moorhens bicker. The lake-bed belches gas bubbles. Merlin and I sit facing the setting sun, enjoying its warmth.

  Two dog-walkers approach, looking hopeful. ‘Do you know where the visitors’ centre is? We’re lost.’

  ‘No, we’re lost too,’ I say happily.

  We trade best guesses, share what information we have, and they wander off.

  Sitting quietly in the sun, by the lake, I think about the ways we seek to make meaning of the wood wide web. Both of the two main models of interpretation that Merlin has told me about – the ‘socialist’ and the ‘free-market’ models – smuggle a very human politics into a more-than-human science. According to the ‘free-market’ model, the connected forest is to be understood as a competitive system, in which all entities act out of self-interest within a cost-benefit framework, regulating one another by means of ‘sanction and reward’ systems. According to the ‘socialist’ model, by contrast, trees act as carers to one another, sharing resources through the fungal network, with the well-off supporting the needy.

  I ask Merlin about this question – about how the politics of representation press especially hard on mycorrhizal studies. It seems to me that what is at stake is not only the relations of nature but also the nature of relations.
<
br />   ‘You’re exactly right. In my field, discourse choice forcefully shapes research directions. “Sanction and reward”, for instance, is a central technical concept in mycorrhizal studies, not just an ornament of speech. The metaphor drives the scholarship. I read research papers with titles like “Unequal Goods Shared under Common Terms of Trade”.’

  ‘That sounds as if it was commissioned by the Ayn Rand Think Tank,’ I say.

  ‘Indeed. Awful. Politically, I’m obviously inclined to dislike the language of biological free-marketry far more than the socialist version,’ says Merlin. ‘Why should we expect fungi and plants to behave as humans started to behave economically in the eighteenth century, with the emergence of the limited liability corporation? I find it so bizarre. It’s one reason I love the Voyria. They demand immediately that you go beyond cost-benefit analysis when thinking about plant life.

  ‘But I’m also sceptical of the socialist dream of fungi as sharing and caring, a rose-tinted vision that sees trees as nurses, every tree a carer to every other, with “mother trees” recognizing and talking with their kin, and “injured trees” selflessly passing on their legacies to neighbours before they die.

  ‘I’m tired of both of these stories,’ Merlin says as we leave the lake. ‘The forest is always more complicated than we can ever dream of. Trees make meaning as well as oxygen. To me, walking through a wood is like taking a tiny part in a mystery play run across multiple timescales.’

  ‘Maybe, then, what we need to understand the forest’s underland,’ I say, ‘is a new language altogether – one that doesn’t automatically convert it to our own use values. Our present grammar militates against animacy; our metaphors by habit and reflex subordinate and anthropomorphize the more-than-human world. Perhaps we need an entirely new language system to talk about fungi . . . We need to speak in spores.’

  ‘Yes,’ says Merlin with an urgency that surprises me, smacking his fist into the palm of his hand. ‘That’s exactly what we need to be doing – and that’s your job,’ he says. ‘That’s the job of writers and artists and poets and all the rest of you.’