On behalf of the Rewilding Community of Practice, we are excited to report on the ‘Fascinating Fungi – Invisible Allies in Rewilding event‘. It was an excellent opportunity to learn about the latest findings and developments in the fields of mycology and rewilding, both from science and practice. Our speakers presented nuanced views on the role of rewilding for fungi and vice versa.
We were thrilled to see this was an interesting topic for you and we thank you for attending and actively engaging with the speakers at the event.
After the speakers’ presentations, we held a Q&A session, at which you had many interesting questions directed at the speakers. We didn’t find the time to answer all of them live, so the Rewilding Community of Practice reached out to the speakers* to have them answer your questions for you.
If you missed the event, make sure to watch the recording.
*we are hoping to have answers from Bethan Manley (SPUN) soon.
Who were the speakers at he Fascinating Fungi Event?
Matsutake Worlds Reserch Group, Author of ‘What a mushroom lives for?’
All you wanted to know about fungi and rewilding
We let all speakers pick their favourite questions. This is what they answered.
The Wood Wide Web, an idea that’s been around for almost as long as I have, has caught the imaginations of many mushroom enthusiasts, especially now that mycology is having a moment out in the public square. The WWW sparks debate amongst seasoned mycologists, who argue of its inaccuracy and misconception. So let’s take the time to explore my views on this, shall we?
For our intents and purposes, the World Wide Web is more or less a decentralised network distributed across space in which nodes on that network (people) can connect with almost every other node and exchange information.
Let’s contrast that to a woodland, and for now let’s stick to the case of ectomycorrhizal (ECM) fungi – those that form characteristic mushrooms in the autumn like this Orange Oak Bolete. A single tree can host several dozen species of ECM fungi, and within each species there may be multiple genetic individuals so that the tree may effectively be harbouring hundreds of individual fungi. Some of those ECM fungi will be associating only with that tree, and some will be associating with multiple trees, but all of them will be transferring nutrients from the soil into the tree based on source-sink gradients.
These fungi can detect self from non-self, and they’re not able to fuse together to form a large continuous mat of mycelium in which nutrients flow freely. They’re individualised, and in fact, can sometimes display competitive behaviour when it comes to root tip colonisation. So the Wood Wide Web is really a collective of countless individuals, and is very different from the free flowing structure of the internet.
So what do I think of the wood wide web? I think it’s a useful heuristic that people can intuitively grasp to speed up their understanding on the topic, even if that doesn’t take them to a complete understanding. What other three-word analogies can you think of that are as swift at bringing people to 50% of an understanding of the topic? You’ll be hard pressed to find anything that comes close to that, and I trust that anyone who is committed to learning more about fungi will eventually develop a more accurate and nuanced view.
Michael J. Hathaway
I guess the first thing to say is that such debates are part and parcel of healthy scientific discourse. In my anthropological training, I don’t think that any statement is proven, rather they can be more or less resistant to challenges from others. Some statements have survived massive challenges, and other statements are pulled down and quickly discarded. I am grateful for Simmard’s work in getting us to ask new sets of questions that sometimes push back on certain deep assumptions about how the world works.
One of the really interesting aspects to these debates is the question of scale, what is the scale of the scientific claim? Is someone saying that these forms of sharing are happening between a few trees of a few species in the Pacific Northwest? Are they saying this is a general principle of all forest interactions? Or is this a general principle of ecological relations writ large? For at least a century, there has been a common assumption from the Anglo-American tradition that life is fundamentally competitive, and so it isn’t surprising that some of Simmard’s claims might elicit a strong response. When there were claims that trees might preferentially provide resources to their kin, this seemed to better fit a model of competitive struggles for resources, but it is also interesting to figure out how this might happen (i.e. if trees are growing by seeds, how is it that they recognize their own kin and might preferentially supply nutrients to them?). Scientists who work deeply with symbiotic relations have been learning more and more about the complexity of such relations that don’t always neatly fit into existing categories such as parasitic or beneficial relations, especially as such relations may change depending on the context and so forth. I’m agnostic about the specific claims to what Simmard or others put forth on the wood wide web, especially recognizing that the knowledge on this topic is rapidly changing, and would encourage further research.
The Wood Wide Web concept has really done wonders for the field of mycorrhizal research. I wouldn’t imagine that we would have such an exploration of mycorrhizal networks in bestselling novels, TV, and countless documentaries without it.
There is a general consensus in the scientific community that it’s highly likely shared fungal networks do exist. However, we just don’t have a lot of scientific evidence on what they do, and there hasn’t yet been direct evidence of them moving resources between different individual trees or plants. We do have a responsibility as scientists to be transparent about situations where a popular concept or idea has little scientific backing. The trouble is that the way a lot of the media I mentioned has portrayed this concept is that it is a concrete fact in science that trees share resources, yet there is almost a complete lack of science to back this up.
Equally, from the perspective of fungal biologists, the WWW concept is a tree-centric way of seeing an ecosystem. It doesn’t give fungi any agency or pay attention to the fact that fungi are complex organisms with their own evolutionary history. So we also need to put as much energy into understanding what the fungi are doing, and what they want, as what the trees are doing.
There’s so much to learn about shared mycorrhizal networks and how they operate in relation to their plant hosts, and this is a really exciting question to shed more light on.
Michael J. Hathaway
At the global level, there are lots of creative experiments happening. In terms of their distribution throughout the world, there are certain hot spots. There is a long history of medicinal use of fungi, especially in Asia, but we could argue that (apart from fungally created penicillin) that the West has systematically underexplored and underfunded medical possibilities.
Michael J. Hathaway
That’s an interesting question, and likely true. I would assume that it would really be a place-specific question and another big question is how do we want to value rewilding, do we want to create our own hierarchy in a given place, or would be want to say any species is equal with each other? I was intrigued by David’s comment that in the UK some are working towards the “biodiversity net gain,” and I was wondering if people are thinking about the relative value of various species presence, or is each species counted as equal? Going for equality starts to get really tricky really fast when one starts to include microbes.
Michael J. Hathaway
Likely a kind of assessment about microbial health would vary dramatically between different ecosystems. Perhaps there will be studies to look at what are assumed to be model “healthy ecosystems” and then do microbial studies, but it might be hard to make generalizations over too much distance. In general, the question of “health” is really tricky but for sure important. In humans, it is sometimes looked at as ‘the absence of disease,’ but we know that this is a very limited understanding, and I would assume that many ecosystems that many experts would describe as healthy also have lots of lots of existing diseases, which is actually part of the diversity itself.
Totally agreed with Michael, what is a ‘healthy’ microbial community will differ hugely between ecosystems. Part of what we want to establish at SPUN is which mycorrhizal fungi make up a healthy ecosystem in different biomes of the world, as a baseline for restoration of degraded ecosystems. This is a really tricky thing to establish, but the more data we gather, hopefully the more we can understand which species are our key players across different regions and biomes.
The best way of introducing native fungi for the purposes of restoration is to co-introduce them with their plant hosts, as they’re unable to survive in the absence of a symbiotic partnership. However, if we’re considering drought conditions, previous research has found that low rainfall actually hindered both plant and fungal colonisation capacity, and once the ground was sufficiently hydrated, there was no need to inoculate with mycorrhizal fungi as they managed to naturally disperse into those environments themselves. On smaller scales (e.g., gardens or small farms), there’s a case to be made that mulching with myceliated wood chip or straw can be both beneficial in terms of moisture retention, but also nutrient enhancement for plants growing in their vicinity.
Questions you asked David Satori
In general, the longer that a tree/plant has been present in a given ecosystem, the more time it had to develop associations with other organisms (e.g., fungi and invertebrates). On the other hand, recently introduced species haven’t had the chance to co-evolve with other organisms, which is why they tend to host far less species than native trees/plants. Whilst there are a lot of generalist fungi out there that can associate with non-native plants, these are typically the commonest of the common species, and not enough attention paid to native plant restoration will result in many host-specific and specialist fungi losing out.
I think the question we should be asking is if we can save fungi’s world! Biodiversity loss is perhaps the single biggest threat on our planet right now, even more dire than climate change, so any efforts to protect species will go a long way. However, there is a place for those interested in nature-based solutions for solving environmental challenges, such as pollution bioremediation.
Given that soil microbes are central to nutrient cycling, organic matter turnover, and even forming defenses for plants against pathogens, our appreciation of environmental microbiomes is beginning to skyrocket within the scientific community. Failure to account for microbial activity is often attributed to poor outcomes in restoration efforts, as has been demonstrated by researchers studying native prairie restoration in the US. Me and Matt go into this topic a fair bit in our book chapter in the Routledge Handbook of Rewilding.
Mostly in field mycology (physically going out to record and monitor species), as well as in professional and academic capacities. I’m not familiar with platforms like Zooniverse, but we have to first generate the data on species habitat preferences, distribution, threats, trends, etc., before we can start analysing!
Questions you asked Michael J. Hathaway
This is an interesting question. Mushrooms are doing pretty well on distributing themselves, they have been at it for about a billion years. When I think about the woods or backyards, sometimes people assume that fungal growth is negative and they remove fruiting bodies from trees, from lawns and so forth but it sounds like that isn’t your orientation. If you’re interested in supporting different kinds of fungi, it is always interesting to bring in wood chips and see who shows up. If you look carefully, you should be able to see an amazing diversity of lichens growing on concrete sidewalks (they can rarely tolerate asphalt materials like pavement/ bitumen), and on neighborhood trees. Although some people try to remove them, they aren’t doing any real harm to the trees. If you pick up a shelf fungus growing on a branch on the ground, it is considerate to place it back in the same orientation, so the spores will continue to shoot out with the right orientation, but that’s the small stuff. In the big picture, it would be helpful to discourage the systemic use of fungicides that are now used in massive quantities in industrial agriculture, often indiscriminately.
Ah yes, a lot of fertilizer can diminish the importance of the fungal network, especially if it was supplying the same nutrient that the fertilizer supplies. That being said, fertilizer is often based on nitrogen, potassium and phosphorus and so providing only nitrogen won’t necessarily diminish fungi supplying other nutrients. These are complex relations, and I once talked with a soil scientist who said that in the “belly of the beast” in the mid-Western USA corn belt, which has high rates of fertilizer and pesticide use, there are still a decent number of fungi present, despite an initial belief otherwise.
I’d love to see more attention to myco-geography. As I briefly mentioned in the event, many texts portray fungal-plant relations as relatively known and fixed, and yet everyday fungi and fungi are trying out new potential relationships, so there is a kind of important dynamism at play that I would like to see more appreciation towards. In much of the scientific framework, it is difficult to get a sense of historicizing evolution, being able to pinpoint the movements of fungi and the development of new relations in time. One of the few counter-examples is trying to study the movements of “invasive fungi,” as they tend to be more visible and evoke more fear (especially toxic ones, such as the Amanita phalloides out here on the West Coast of North America.
Questions you asked Bethan Manley
As I mentioned, we have a thriving research community of SPUN Science Associates that is growing every day, and these are really the crucial component of how we increase our data on mycorrhizal community composition throughout the world, so we always encourage anyone who studies soil, fungi, or mycorrhizae to get involved. Aside from scientists, we are incredibly keen on getting more people involved in some form of practical citizen science approach. Join the SPUN newsletter and watch this space! In the meantime, we always encourage people to get involved in their local mycological societies and to see what’s going on in their local areas for fungal rewilding – we want people to form their own mycological networks!
We do – and as I’m sure you can imagine, it looks very different to the EMF map. It’s remarkable to be able to visualise the differences in the predictions for these distinct mycorrhizal types. However, the AMF map is based on ITS amplicon sequencing data, which many people will know does not capture AMF diversity particularly well, though it’s great for EMF. Because of this, the AMF map is not based on as much data as we’d like, and we’re working to change this. We have started using AMF-specific primers as well as general fungal ITS primers for all of our samples, and hopefully soon this will give us much more in-depth knowledge on AMF species and their distributions across the globe.
We are interested in total diversity, but we will always include new sequences in our assessments, too, this is very interesting to us. The trouble with this work is the question – what is an AMF species? These fungi have hundreds of nuclei per cell, many of which have different DNA sequences, and there are different isolates that can look like different species. Without morphological data through culturing, which is very very difficult for these obligate symbionts, we can’t register new AMF species, but we certainly can assess which different sequences are out there.
I have no idea sadly! Something I’d love to look into.
Additional resources on fungi and rewilding that our speakers shared
- David: RoutHawkins, S., Convery, I., Carver, S. and Beyers, R. eds., 2022. Routledge Handbook of Rewilding. Taylor & Francis.
- David: Webinar: Ted Green and Lynne Boddy Talk a Load of Rot
- Michael: A fascinating short film produced by one of my students that emerged out of conversations about taking a “resource perspective” towards fungi: https://player.vimeo.com/video/333458467?h=5279593d53
- Michael: Another great film by one of our audience members, now based in Sweden
- How fungi facilitate forest formation. Considering Fungi; https://vimeo.com/705153619
- Michael: The Fungi Foundation is one of the world’s most dynamic and engaged groups on getting fungi visible in policy and promoting top quality fungi education: https://www.ffungi.org/
- Michael: the first book in the trilogy by the Matsutake Worlds Research Group: https://press.princeton.edu/books/paperback/9780691220550/the-mushroom-at-the-end-of-the-world
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