roots

I led a primary school assembly yesterday, in which I wanted to help the kids learn something amazing about tree roots. As an experiment, I'm not sure it quite worked, but the idea was to get a number of children, randomly scattered around the school hall, to stand up and be trees - and then for each of those trees to be linked to all of the others by a complex root system - involving children around the "trees" holding the tree's ankles with one hand, and with their free hand beginning a chain of held hands, spreading outwards. If it had worked (it didn't!), one tree could have sent messages to another tree, by wiggling its "roots", and the "roots" passing on the message by squeezing hands, down the chain until another tree's roots were reached.

Somewhere along the way, the excited children got a bit lost with instructions from me that were, in the heat of the moment, just a little bit too complicated for a hurried demonstration. But what I'd wanted to illustrate was the incredible interconnectedness of our world - and more specifically, the amazing phenomena called mycorrhizae [from the Greek: mikas = fungus, riza = root].

Through scientific discoveries that date back to the late nineteenth century, but are developing right now at an accelerating pace, we are discovering more and more about the complex symbiotic (i.e. mutually dependent) relationship between plant roots and the "macrofungi" that attach themselves to them. The fungi help plants get minerals that the roots alone can't absorb, and in turn the fungi live off sugars that they get from the plant's photosynthesising processes. But more than that, the mycorrhizae are the structures of the fungi that extend the plant's root system by becoming a functioning part of it. Tiny threads of fungus called hyphae extend the mycorrhizae further by growing into spaces where the roots can't go, accessing nutrients beyond the plant's own reach.

But there's more. The mycorrhizae also connect the roots of one tree to the roots of others, in what Susan Simard has termed the "wood-wide-web". Through this web, nutrients flow to the trees that need them most (such as the youngest ones), and information and energy are transferred from dying trees to those that are continuing to grow:

"We have learned that mother trees recognise and talk with their kin, shaping future generations. In addition, injured trees pass their legacies on to their neighbours, affecting gene regulation, defence chemistry, and resilience in the forest community. These discoveries have transformed our understanding of trees from competitive crusaders of the self to members of a connected, relating, communicating system." (Simard 2016:249)

In this communicating system - over 90% of plants have some kind of mycorrhizal relationship, and some scientists believe these networks may span entire continents - chemical signals can be transmitted from a plant under attack (from insects, herbivores and pathogens in the air or soil) to neighbouring plants, stimulating protective chemical responses in those other plants. But these incredible networks are also fragile: plough up the soil or fertilize it with agricultural chemicals, dig it up to build houses and roads, and the mycorrhizae are, inevitably, destroyed. Lone trees on city streets, cut off from their neighbours, are stranded, vulnerable.

***

I dared to venture into this awesome "underland" (to use Robert MacFarlane's poetic term) with a school full of primary children, partly because it felt like a fabulous visual metaphor for the interconnectedness of all living creatures (humans included) in our world - this was a Harvest assembly, it should be said. But partly also for its own sake - I wanted to find a way of sharing with them one of the biggest "wow" moments of this year for me, discovering, through Simard's work and those who have written about it, a stunning, hidden dimension of the infinitely complex ecosystem we inhabit.

As a theologian, it is all too tempting to appropriate the mycorrhizal "wood-wide-web" as a theological metaphor, primary-school-assembly-style. And it does indeed have fabulous metaphorical potential. But in our developing "theological ecology", it feels like the mysterious fungal connections between the roots of plants and trees demands harder, more profound theological work of us. If the Holy Spirit, the "go-between God" (as John V. Taylor termed her), is not just "like" the pulses of air that constitute our human-to-human communication, but is somehow in them (Pentecost, to take the most obvious example), then might we dare say that that same Spirit is in those chemical pulses that move through the complex root-and-fungus networks stretching out through the dark earth beneath our feet? What are doing, theologically, when we poison, dig up and disrupt those networks? What would healing and flourishing look like, and what is our role as human beings within that? What might we humans - we Christians among them - learn from the mycorrhizae?

References:

• Glenn Albrecht, Earth Emotions: New Words for a New World, 2019, pp.95-99
• Robert MacFarlane, Underland: a deep time journey, 2019, pp.87-116
• Suzanne Simard, 'Notes from a Forest Scientist', in Peter Wohlleben, The Hidden Life of Trees: what they feel, how they communicate, 2016 (see also Simard's TED talk, 'How trees talk to each other')
• Isabella Tree, Wilding: the return of nature to a British farm, 2018, pp.19-22, 47