How to Harness the Ancient Partnership between Forests and Fungi | Colin Averill | TED Talks

(1) How to Harness the Ancient Partnership between Forests and Fungi | Colin Averill | TED - YouTube

https://www.youtube.com/watch?v=qN8vzlcYAE8

Transcript:

(00:00) foreign forests play an essential role in regulating the earth's climate however most of what we know about those forests is actually based on things we can measure above ground so historically a colleges like myself would come to this place and we'd count the number of tree stems we'd find we'd identify which species they are and today would probably remotely sense features of this forced canopy from space and all of this absolutely makes sense above ground is where photosynthesis happens photosynthesis is how carbon and

(00:42) energy enter forests photosynthesis is how trees can remove carbon dioxide from the atmosphere however we also know most trees are limited in some way by soil resources like water or nutrients and to access those resources trees have to build roots and trees build an incredible amount of roots so in some forests there can be as much or more biomass below ground and root structures as above ground in stems and leaves Decades of research have now made very clear that below ground ecology so what's going on in the soil is really

(01:16) essential to understanding how these Forest systems work however if you follow these root systems all the way out to their very terminal ends the finest tips in the root system and you look closely and I mean Super closely like you're going to need a microscope closely you discover a place where the tree stops being a plant and starts becoming a fungus so most trees on earth form a partnership or what scientists call a symbiosis with mycorrhizal fungi so this in my opinion is one of the most remarkable images ever captured of these

(01:49) organisms so in the background at the top you can see this dense network of fungal hyphae these are essentially like Roots but for fungi instead of plants and in the foreground you can see these incredible multi-nucleated fungal spores which look totally unreal but absolutely are these are the reproductive structures of the fungus these have the potential to become entirely new fungal networks mycorrhizal fungi are essential to how basically all plants access limiting soil resources there's actually evidence that when

(02:21) plants first made The evolutionary transition from living in water to living on land they evolved this symbiosis before they even evolved the roots and so this partnership between forests and their fungi is ancient and it stretches back hundreds of millions of years however these roots don't have to be just fungi they can also be for instance bacteria so these circular structures in this root Network are called root nodules they have symbiotic nitrogen fixing bacteria and what these bacteria do is actually convert

(02:53) nitrogen gas in the atmosphere into plant usable forms and in turn they nurture plant growth and the complexity of soil biology just keeps going so these roots in my Ants are embedded in an even more complex network of Free Living bacterial and fungal decomposers and Archaea and protists and microscopic soil animals and viruses the biodiversity of soil communities is astonishing we now know a handful of soil can easily contain over a thousand coexisting microbial species and so all of this this is the soil microbiome this is the

(03:31) forest microbiome this is the ecosystem microbiome so breakthroughs in DNA sequencing technology have finally turned the lights on below ground DNA has allowed us to see these microbial communities in unprecedented detail and only recently at unprecedented scales yet despite these breakthroughs I'd argue we still don't know the answers to seemingly simple questions like this what is a healthy Forest microbiome look like we're far closer to answering a question like this for people than we are plants

(04:04) the human microbiome project has really LED in this area so the human body is a microbial ecosystem each of us houses an incredibly biodiverse community of bacteria in our gut and that has a profound impact on our health this was discovered by medical microbiologists using DNA sequencing to characterize which bacteria live in hundreds of people's bodies and importantly also noting Health features of those same people so are they sick and if so with what what's their blood pressure their Digestive Health their mental health and

(04:34) by combining all of that information those microbiologists could begin to identify combinations of bacteria linked to health and disease and these analyzes became a road map for the development of human microbiome transplant therapies which is essentially ecosystem restoration but for your gut microbiome and these therapies are now on the road to Market to treat some of these diseases today and so drawing from this work my team asked what would it look like to take the human microbiome project approach but apply it to the forests

(05:07) what could we discover about the forest carbon cycle could we identify places where we could actually do below ground microbial restoration and in the process combat climate change over the past three years we've been working with Forest scientists across Europe to do exactly that in each of these locations scientists have been documenting Forest Health for decades and so we asked our forest research Partners to go out to each of these forests and collect a small sample of soil which they then ship back to our lab in Zurich so we

(05:38) could extract and sequence DNA which allowed us to understand which microorganisms and particularly fungi live in each of these forests and then finally we use statistics and machine learning to relate which microorganisms live in a forest to a really important Forest Health metric tree growth rate and carbon capture rate above ground now once we controlled for the environmental drivers of tree growth so how warm and wet each of these places is as well as other variables we know control background site fertility

(06:09) we discovered that particularly which fungi colonized the roots of these trees is linked to three-fold variation and how fast these trees grow how fast they remove carbon dioxide from the atmosphere so put another way these correlations implied that you could have two Pine forests sitting side by side experiencing the same climate growing in the same soils but if one of them was colonized by the right community of fungi on its roots it could be growing up to three times as fast as that adjacent Forest and furthermore these patterns were not

(06:44) driven by the presence of particularly High performing species or strains but instead they were driven by biodiverse and completely different communities of fungi and so these fungal signatures are super exciting to us because they imply an opportunity to manage and in many cases actually rewild the forest fungal microbiome so for example can we reintroduce fungal biodiversity into a managed Timber forestry landscape and in the process can we make those trees grow faster can we make them capture more carbon in

(07:19) their tree stems and in their soils can we rewild the soil and combat climate change and these aren't just rhetorical questions we've actually started doing this so this is one of our field trials in Wales in the United Kingdom it's run in collaboration with the charity there called the Carbon Community it's 28 Acres or 11 hectares and it's set up as a block randomized controlled trial this is analogous to how you would run a drug trial but in this case it's for trees instead of people

(07:48) and here we do a pretty straightforward experiment we either plant trees business as usual which is just direct planting of seedlings into the ground or we plant trees and at the moment of planting we had a small handful of soil but it's not just any soil it's soil sourced from a forest our analyzes have identified as harboring potentially High performing fungi so since we reintroduced microbial biodiversity into some of these sites we've observed that where we actually did that we've been able to accelerate

(08:24) tree growth and carbon capture and tree stems by 30 to 70 percent depending on the tree species or put another way where we've manipulated and rewilded the invisible microbiology of this place we've begun to change how that entire place works now it's important to emphasize that we're really excited about these findings but we we also understand they're still early we want to see many more large-scale field trials and many more locations with many more years of data however Beyond just these carbon and

(08:57) climate outcomes I think the most exciting thing here is that we can actually do this with wild and Native and biodiverse combinations of microorganisms and while we pointed this Approach at forestry in principle this kind of science has the potential to generalize to all of our managed landscapes we can begin asking questions like what is a healthy agricultural microbiome look like thinking across both food and Forest Agriculture and there's reason to think of biodiversity first approach may be particularly

(09:28) powerful here and that's because the history of Agriculture has been an exercise in reductionism we've identified High performing plant species and then strains and then we've selectively bred them and now we genetically modify them and finally we plant those organisms out in vast monocultures so a single plant species as far as you can see and to be clear this is produced very productive Agro ecosystems but it's also produced ecosystems we're coming to understand are remarkably fragile systems increasingly sensitive to

(10:01) extreme climate events and novel pathogens systems incredibly reliant on chemical inputs we're coming to understand have really serious externalities so we now have the data computational tools and the ecological Theory to start going the other way to lean into biodiversity and complexity and once we do the question really becomes by rewilding our soils can we make our managed food and Forest Landscapes reservoirs of below ground biodiversity and in the process can we enhance yields and carbon capture and

(10:33) all the other services we ask of these ecosystems I think there's a lot of reason to be incredibly hopeful here and I think we also shouldn't be so surprised that these microscopic organisms have the potential for such enormous ecosystem scale effects and that's because we've known now really for a long time the four star fungi and they're incredibly biodiverse communities of bacteria in Archaea and protists and microscopic soil animals and viruses soils are the literal Foundation of terrestrial ecosystems and the microbial

(11:09) life that inhabits soil represents some of the most complex and biodiverse communities of life on Earth for the first time DNA sequencing is turning the lights on below crap it's allowing us to see these organisms in a precedented detail and unprecedented scales imagine studying plant biology but you never really knew if you're looking at a sequoia tree or sphagnum Moss and then all sudden you did that's what's happening right now in Global Environmental microbiology and so we should expect this revolution

(11:49) in our understanding of these microscopic organisms and particularly fungi to transform how we understand and how we manage our ecosystems in a foundational way thank you [Applause]