Ayana Young  Hello and welcome to For The Wild Podcast. I'm Ayana Young. Today I'll be speaking to Christian Schwarz, a naturalist currently living in Santa Cruz, the land of milk caps and honey mushrooms. Christian studied Ecology and Evolution at UCSC, and now spends his time photographing, teaching about, collecting, and researching macrofungi. He is co-author of Mushrooms of the Redwood Coast. Fungi satisfy his curiosity with their seemingly endless forms from the grotesque to the bizarre to the sublimely beautiful.

Christian Schwarz  They come in a zillion colors, every hue, every shade, every intensity is represented. It seems just structurally, texturally. They engage all your senses, if you let them, and if you go out of your way, you can even hear some mushrooms.

Ayana Young  Besides dabbling in mushroom taxonomy, he loves fish, plants, nudibranchs, moths and dragonflies. He is passionate about citizen science, especially iNaturalist. 

Oh, Christian. Well, this is such a beautiful day that I get to interview you. I remember seeing that you were teaching at the Radical Mycology Convergence. I think it was last October, or maybe the October before that, and I wasn't able to join but I was reading your bio, and I actually have Mushrooms of the Redwood Coast sitting with me. My hand is on this beautiful book and I'm just very intrigued by your knowledge and curiosities and thoughts around fungi and climate change. So thank you so much for joining us today, and I'm really looking forward to diving in deep to many different threads of the fungal queendom.

 So I want to start off with a pretty easy first question, just to get us rolling. So here I am. I have your book, Mushrooms of the Redwood Coast, and it's beautiful. It's a book you co-authored with Noah Siegel, and it includes descriptions, illustrations and photographs of over 700 different mushroom species along what you call the Redwood Coast. So to begin our conversation, I would like to ask how was this field guide brought into fruition? And if you could share some of the tremendous fungal diversity that is contained within this area.

Christian Schwarz  Well, the book, I always say, we kind of wrote for ourselves because we had been using the existing field guides to get to know the mushrooms that we were experiencing up and down the California Coast, and we felt that there were big gaps in what was available at that point. We had learned a lot since the last major field guide was published, Mushrooms Demystified. And there were new species. There were new ways of recognizing species, there were new distinctions that people had become sensitive to. And there was also just this revolution in photography where it was easy to make lots and lots and lots of color photos that really captured the essence of a species, and we wanted to have all of that in one place for our own to help us get to know the characters in the woods better. And essentially, we decided that we had already taken so many photos, and we'd already gotten so familiar with so many species that it was time for us to write a book, and that took a little convincing of ourselves. We had to convince each other that we were ready and, I think in retrospect, we weren't ready, but you don't start a project by being ready. You start a project and then by the end of it, you did well enough. 

So we basically made a list of all the species we really felt were common enough to warrant inclusion in the book — things that people would likely see, as well as a big smattering of, you know, rare things and treats other species that maybe you're unlikely to see, but we want you to to be able to look them up if you do have the good luck of finding them. And then we spent six years traveling up and down the California coast, sort of really exhaustively looking through different kinds of woods that represented different flavors of the Redwood ecosystem, all the way from the southern limit down in Big Sur Monterey County all the way to the Northern Limit in Southern Oregon and everywhere in between old growth, second growth, recently logged, and all of the surrounding habitats as well. So it's not just redwoods that we cover. It's the hardwood forest of tan oak madrone, the beautiful live oak groves that characterize the sort of warmer, drier southern climate, and even the chaparral and the cypress — the Monterey cypress, that had been relatively under explored. 

And after six years, we ended up with way more species than we could fit in the book, way more. Photos and the publisher would let us print, but we were still really happy with our experience working with Ten Speed Press. They allowed us to really pack in as much of that biodiversity in between two covers that we could reasonably get away with. So we're really proud of how the book turned out. 

And it really....As far as the biodiversity, giving you a sense of what lives on the Redwood Coast, I think we did a good job because a lot of the diversity is in the redwoods, and especially the special diversity, the diversity that sets California apart from the rest of the United State because redwoods are almost uniquely a Californian phenomenon, but also the other habitats that make California special, like Monterey pine forest has its own unique assemblage of fungi. Same with the Monterey cypress. There's some of the most distinct and unique fungi live with Monterey cypress. And then we tied it to the rest of the country. There are things that occur across the northern hemisphere that also are present on the redwood coast, and we managed to get a little bit of all of it. So I think we're really pleased with being able to get in as many photos and as many species as we did.

Ayana Young  Yeah, it's a book that has been off the shelf for a few months now, and my little cabin here in the redwoods, almost every day when I go out and find a new friend, a new fungal friend, I come back and I check out your book and try to figure out what I'm looking at. The diversity of fungi is so enormous, and even the most expert of us still are, I think, baby learners in this field, and we may never truly know the complexity and just vastness that the fundal queendom holds. So it's really a wonderful resource and recommend it to anybody who wants to learn more about this region. 

And I really liked hearing how you were talking about the different regions in California, these really incredible ecosystems, the hardwood forest, the redwood forest, the chaparral, and it just reminds me that without fungi, plants may have never been able to populate the land in this way. And thinking that nearly 90% of all plant species have mutualistic bonds with fungi, in some cases, one plant species will have over 100 species of fungi connected to its roots. So it's really this remarkable companionship. And to kind of take that thought further, as you were talking about the old growth and the second growth, and going into places that were just logged, I too really explore the forest in its different variations of human interaction and resource extraction. And I think about the fungal diversity and ecological loss, and what is being threatened due to logging, monocropping and forest thinning. And so, yeah, I just want to pose that question to you in terms of fungal diversity and fungal health, what is being threatened when we see this massive resource extraction projects come in and really rape a forest, and what does the loss of old growth forest mean for macro fungi? So it's kind of a two part question, but I'd love you to be able to speak to both of them,

Christian Schwarz  So both of those, the answer can almost not be overstated in how serious the consequences are for macrofungal communities. And, macrofungal communities are kind of just the stand in for the whole fungal community, much of which isn't detectable to our sensorium. You know, our senses are not really equipped to be in the world of most of the diversity of fungi because they are microscopic or endophytic or underground or out of sight, and thus out of mind. So really, I think of macro fungi as really the way that we can connect with this kingdom. But it's just the tip of the diversity. You know, it's just the tip of the iceberg in terms of who's there. Extractive industries that clear cut for us, and this is, unfortunately still super common in the Pacific Northwest. Basically, it takes the fungal community from, you know, potentially 1000s of species in a very small area to not zero, but, you know, a handful or a couple 10s. So it's orders of magnitude difference. 

Old growth is sort of where fungal community, macrofungal communities, get as diverse as they get anywhere in the world. Old growth forests can host, even if there's only a few trees, a few tree species relatively undiverse from the perspective of woody plants, they can have 1000s upon 1000s of macro fungi and, like I said, that's just reflective of who knows how many more 1000s of micro fungi and endophytes and soil fungi. So old growth forest is something we should be desperately concerned with conserving, especially in the Pacific Northwest. It is where macro fungi are most diverse, where some of the rarest species occur, where some of the most unique evolutionary lineages are found, and they're under threat from not only direct human caused impacts like logging. 

But there was a study that came out, I think, yesterday or just this week, by Kabir Peay at Stanford University, who's a really well respected, well-known Macro Fungal Ecologist, who did an analysis in his lab about the likely impacts of climate change on the diversity of macro fungi across North America and they found that the West Coast is likely in for a pretty large reduction in the diversity of macrofungal species in the next few decades due to the projected effects of climate change. So they use modeling of the climate that we expect to be coming and the tolerances of the fungi that live here currently. And for the West Coast, it doesn't look good. Western North America isn't poised to gain species out of this. It's poised to lose a lot of diversity.

Ayana Young  And is this fungal diversity loss related to warming temperatures, drought...What is leading him to think that the diversity will be lost?

Christian Schwarz  It's not single factorial. It's like everything related to climate change — this sort of, like, self-reinforcing web of feedback loops. So some trees may no longer be able to make a living if the climate warms or if the soil dries out. And if the trees leave, maybe the fungal species had enough flexibility in its physiological envelope to continue living there, but its host tree is no longer able to so there's a co evolutionary consequence. These species can be so closely tied that if one leaves, so does the other, but all of those things are probably important. Sometimes it's just the temperature that rises too high on average, and sometimes it's just aridification of the soil, and sometimes it's a combination of the two, and sometimes it's secondary. The other organisms with which a macro fungus interacts may change their distribution or their physiology or their behavior, and that kind of thing adds up, and it becomes hard to tease out any one reason, but overall, the picture is quite clear.

Ayana Young  Yeah, it reminds me of what's happening with the salmon in the Pacific Northwest, and the collapse of salmon, and how people are going well, "I don't know. We don't know. We don't know why they're collapsing." And again, it's not just one issue. There's compounding issues that are affecting their habitat and their health. And so it, to me, feels very similar to the fungi. 

And yeah, I noticed last year when I was in the forest, it was, I don't want to say bare, but it was kind of shocking how little fungi was coming up. And even speaking to people up through the North Coast, they are saying, "Oh, it's the worst mushroom season in 30 years," and so maybe I felt a little precursor of what is to come. 

And I do want to talk more about fungi and climate change, but to get back to the resource extraction topic. Now, of course, it makes sense that logging old growth would be completely detrimental to fungi, and I'm definitely an advocate of ending old growth logging, and our work in the Tongass has a lot to do with that, of course, with the Roadless Rule. But there's a lot of talk, especially with the fires, around thinning, and how thinning can be helpful. It can reduce fire. It can…Some people say it can actually stimulate diversity because it gives more room to trees, and it allows us to get to, quote, unquote, old growth status faster if we go in and manage the forest. And I really go back and forth with this, because part of me feels that tending the land is something that we as humans have done for a really long time, and at some point, we were actually helping to support more biodiversity with the way that we tended. Now, all industrial methods of managing land, to me, have a lot of blind spots and issues. So just specifically, what are your thoughts when a forest, instead of being clear cut, is being thinned for what people may call, like, an ecological purpose?

Christian Schwarz  Yeah, so with the disclaimer that I live on the California coast, where thinning is less often talked about, and fire is not as I mean, it's still a concern, but it's not like it is in the Sierra Nevada foothills, and thus I'm not intimately familiar with the various complexities of the topic. I will say that there is no question in my mind that the forests are excessively dense due to lack of management or mismanagement and total fire suppression in many places in California, and we're sort of inheriting the consequences of a lot of that. I have no doubt that that is the case. I don't know enough about the facts of how thinning occurs and whether or not it gets quickly deranged by timber permits versus managing actively for fire without other concerns, but I think there has to be some amount of thinning that we do in the near future because we're inheriting far too many of the most catastrophic consequences of overcrowded forests of thin trees, or, you know, young sapling trees. There's no doubt in my mind that we do have to do something of some form, and I think we'll probably do it wrong a lot of the time, and I think there's only space to get better at it, but to not consider it at this point doesn't seem like a viable option to me. 

I can say for sure that a lot of the forests that were logged here and have regrown without management are very crowded and are less biodiverse in terms of macro fungi than those where occasional management occurs that opens out the forest, especially clearing out the understory. Right now in Santa Cruz, they're doing fire specific thinning along the edges of one of the main thoroughfares through the mountains and the remaining forest. I think Cal Fire is doing most of the work looks amazing. Like I'm actually quite excited for what it's going to do for fungi in the near five to ten year period. Now, I don't know if the best case scenario is actually going to come true. It could just get regrown really badly with invasive weeds, and that will depend on how the follow up management occurs, but from my perspective right now, it looks promising. And that's about, you know...I'm not very sophisticated on this topic. It's something that I think a lot of people are doing more research on, because it's just such a pressing matter for the state right now, and I look to them and hope that they'll continue to just sort of be creative about the ways they get better at it over the near 10-20 year period.

Ayana Young  Interesting perspective. Thank you for that. It's not one that I've really thought in that way, and I'm happy to hear that you're excited, that that's uplifting. 

Christian Schwarz  You know, it's always mitigated excitement, but I gotta find little things to hold on to.

Ayana Young  [Laughter] Yeah, definitely. Well, in terms of things to hold on to, I think a lot about just aesthetically mushroom diversity presents itself in just incredible colors and formations that feel otherworldly. And I know people are really drawn to the fungi for that reason. And I know you've put so much work into really showcasing these fungi through your book with all the beautiful colored photographs, and all the time that I think what the six year period for taking these photographs. And I'm wondering if you could speak to your esthetic appreciation of biodiversity from the perspective of fungi and as a visual creature, how have you been enraptured by the diversity of macro fungi and the gifts produced within the wisps of mycelial thread?

Christian Schwarz  I feel like it is of central importance how much I respond to biodiversity aesthetically, like that is really the reason that it matters. Beyond anything else, for me, the reason that biodiversity is my sort of permanent mental home in the universe is that I will never cease to be absolutely floored by the sheer beauty, the overwhelming beauty, the intricate beauty, the bizarre beauty, sometimes the revulsive beauty. Like I often say that mushrooms are both the most disgusting and the most beautiful things in the woods simultaneously. There's nothing quite like a rotting mushroom that's full of maggots and, sometimes, if you spend enough time with it, it transcends, and you're like, oh, wow, there is a beauty in this too. So mushrooms are sort of the most extreme version of it. They were the hook that really brought me into the world of all biodiversity, and now it's sort of gotten out of control and I pay attention to everything as much as I can. But mushrooms got me in, and they probably will never let me go. They come in a zillion colors, every hue, every shade, every intensity, is represented. It seems just structurally, texturally - they engage all your senses, if you let them, and if you go out of your way, you can even hear some mushrooms. I think people don't listen to mushrooms enough, but you can knock on their stems, and you can hear the different textures that reflect what their cells are woven like. And you can wave a cup fungus in the air, and if it's been still enough, it'll eject all its spores really quickly and you can hear it hiss. Sometimes, you can hear the faint hum of fungus gnats as they try and lay their eggs in the gills of the mushrooms. So they are really there for all your senses, probably even some senses that we don't have names for if you engage them in other ways. I think the primary benefit for me mental health wise of biodiversity, is the aesthetic pleasure the home for my attention. You know all you get to spend your only currency in the universe is your attention. That's what you get to do for 100 years if you're lucky, tops. Spend your attention somehow. And biodiversity, for me is that's the mountain I want to climb. That's the well I want to fill. I just want to spend my attention on biodiversity and its aesthetic value.

Ayana Young  Oh, that was lovely. I would be a very lucky person to spend the majority of my attention currency on biodiversity. I'm completely enraptured by it as well. And I think it's something that the beauty and the mystery and the intrigue and curiosity are ways that pull us into loving the Earth more deeply and be willing to protect what we love and are enraptured by. And so I think that aesthetic pull actually, somehow it's more important than just the surface level of something capturing our visual attention. 

I want to now speak to how you are an advocate of citizen and community science and turning into the topic of recognition of fungi nature. And I'm thinking about how contributors of macro fungal citizen and community science are really delighted to a slower process of observation and an understanding of multi species ecology that might not otherwise be so obvious and mushroom hunting or mushroom sightings, they require a kind of slow wandering. And so I'm wondering if you could speak to how you see citizen science as an opportunity to allow practitioners to observe slowly. And what are the benefits of these types of observations?

Christian Schwarz  One thing is that so far, we've kind of overlooked or not even spoken about mushroom picking, mushroom gathering, mushroom eating, and that sort of low level person and forest community and forest interaction is not trivial, and in my estimation, is actually like probably more important and more accessible than anything that we could call citizen science or community science. And it's not something I do a lot of personally, but I actually think that it is the way that a majority of people probably first get into loving healthy forest is through their stomachs and through their taste buds, is loving the feeling of picking wild food and being able to eat it and share it with their friends, and perhaps even picking with their friends. So I think that's really important, and might even be better for inspiring love, although not necessarily slowness. People tend to get a frenzy with mushroom picking sometimes, and I think that's where community science and citizen science really comes in. It asks you, or allows you, or sometimes even pushes you, to look at the other organisms that aren't useful from a gastronomic perspective or don't delight you with their flavors or their utility in any concrete way. It allows for people like me, whose aesthetic alignment is the strongest driving force, to have a space to talk to each other and make that central to what we're doing out in the woods — is documenting and sharing the various beauties, the various multiple species' ecologies that we encounter. But just like anything, it can be done badly or thoughtlessly or quickly and so fast that you're not really getting what I think is the biggest value of being in the woods which is to slow down and to pour deeper attention into your surroundings. 

So community science...For a long time, I said citizen science and I'm starting to change over to community science  because citizen for a lot of people, brought up sort of weird ideas that you needed to be validated for entry into the community. You know, it harkens back to all of our language about borders and permission, and its most effective form is when barriers to entry, barriers to participation, are lowered down to the absolute minimum, so that you are trying as hard as possible not to exclude anyone from being able to participate if they choose to. And what that does is it harnesses and takes advantage of and revels in all of the diversity of human brains, you know, all the ways that people want to interact with nature. Where they have a place in this community, people who are sharing what they're seeing with each other. So by taking that barrier to entry, that barrier to participation, to sharing what you're seeing down to almost nothing, it means that the people who are only interested in slime molds and nothing else can be there. It means that people who are only interested in one tiny group of fungi can be there. It means that people who only ever want to participate once or twice in their entire lives can be there. There's no rules, there's no onus of responsibility. There is simply an acceptance that if you want to share what you're seeing in the woods with us, we're here to see it, and we're here to revel in it with you. So it's sort of a somewhat structured, a minimally structured space for play that really gets us data that we were never able to get before. So to bring it back to something more practical or more Science-like, with a capital S, the end result of all of these people at play with no rules or minimal rules and minimal structure, are these massive, very fine grained data sets of where people are wandering over the landscape and what they're turning their eyes towards, what they're turning their ears towards, what they're turning their touch towards. And I can't imagine explaining these data sets that you get from something like iNaturalist to a professor who was working in ecology 30 or 40 years ago. It would sound like some sort of magic, some sort of unbelievable end goal, and yet here we are. We now have these data sets, and it's sort of up to scientists now to figure out what to do with them, to figure out how to clean them up, analyze them, use that massive body of sensation and distill narratives out of it, distill findings out of it, distill discovery out of it. 

And many of the advances that have revolutionized science have come in this way, which is not that they were built for a purpose or to solve a problem, but were built for a function that suddenly allowed a whole new world of sensation to be used as data, a whole new kind of evidence to come into the fold of what science could work on and think about. And I really think that's what citizen science platforms like iNaturalist have done, is they've created new ways of talking to one another that may not be new in any qualitative way, but allow us to do it at a scale and in real time and at a level of sort of depth and granularity that makes it feel like something very new, very different that didn't exist in the world before. So that's why I'm so excited and such an advocate for community science, or citizen science.

Ayana Young  I do want to speak more to that, but at the beginning of your response, you touched on mushroom hunting, and I do want to dive into that a little bit more. Now I was reading that the global market for mushrooms is estimated to be worth $42 billion a year. But even separate from this global exchange, we've seen the growth of mushroom foraging on a smaller scale as well, through social media, and I don't want to say pop culture, but more than just fringe at this point. So for instance, I'm wondering if you can share what the ramifications of this craze are to the forest ecosystems. 

Christian Schwarz  The first part is to say that you're not wrong. There was, I think it was a car commercial from one of the major US manufacturers recently that advertised their SUV by showing it driving out into the woods and the driver getting up and picking a morel like there was a full close up shot of a morel being cut out of moss. So it's not the same as it was 10 years ago. People like this in a different way in the United States now it has reached some sort of new peak of cultural consciousness, which is, I just mean awareness, perhaps consciousness probably implies too much thought going into it. So there is real reason for concern. But the reason for concern, in my view, is not about the act itself of mushroom picking. It's about the volume and the structure around it. So the biggest problem here is simply how many of us there are at any one time potentially doing it. I think any one person picking mushrooms or any small community picking mushrooms is great. It's wonderful. It's like one of the lowest impact ways that people can viscerally, extractively engage with the woods, which is what all of human prehistory was, was eating off the landscape, living in the landscape, exchanging nutrients and time with the landscape, being very closely, physically in touch with the living world. And what little remnants of that we can we can still hold on to, I think, is worthwhile, really worthwhile, deeply worthwhile — to have our hands in the dirt, to be eating wild mushrooms, to care about a forest that can produce the things that we look forward to. That said, when you scale it up to people who have SUVs, and when you scale that up to 300 million people across the United States, and you have social media that directs people's attention to what's happening right now and where it's happening in really efficient ways. And I don't use the word efficient positively there. I think the biggest problem here is the efficiency. It allows people to get in and extract or get into the forest and pick mushrooms, or compete to pick mushrooms in ways that are too good. They're too good at it. The slowness, the inefficiency, the wandering, the failing to find mushrooms, get sort of parsed out. And I don't like it when people get too efficient at anything good, because it tends to get corrupted really fast. 

The biggest impacts that mushroom hunters pose to the forest are pretty obvious. There's the easy ones, like littering. Mushroom hunters definitely have not always been responsible in keeping the forest clean behind them. And then there's simply the impact of hundreds of people going to the same places over and over throughout the mushroom season and trampling down duff and trampling down soil, compacting the air spaces between soil granules that don't allow for water to penetrate in the same way or don't allow for air to circulate in the same way, don't allow for plant roots to survive. And that is all compounded by the legislative structures around mushroom picking. So when you only have a few parks in coastal California where mushroom picking is legal, you concentrate a lot of foraging activity into those parks, and all the negative consequences are amplified rather than reduced. So the ways that we bureaucratize people's access to the woods have actually contributed to greater impact rather than less impact. 

In my ideal way that this would work, there has to be some balance between a free for all, where people are just allowed to pick and harvest mushrooms everywhere, and the current situation, which is basically a prohibition, at least on the coast. In my mind's eye, a permit system where you, I don't know, do some volunteer work, do some trailer work, remove invasive species for X amount of hours during the summer and during the winter you get, in exchange, a permit to pick some amount of mushrooms. Now, obviously commercial picking throws a further complication into this that people need to manage intelligently. As well as you don't want this to be regressive. You don't want it to be something you can just pay for, like a fishing license, which is in many cases expensive. So for some people, it's prohibitively expensive. I don't want that to be the structure that mushrooms embody. I would like it to be either volunteer based, if you can't afford to pay for the permit outright, but some way of allowing access in a dispersed way across the landscape in a bigger way that just makes this something that families can do together, that parents pass on to their children, that grandparents do. It's multi generational. It's community strengthening and community organizing rather than sort of what we've got now which is a matter of evading park rangers who have become de facto law enforcement. And that's not a good feeling for the woods, for anyone, much less someone who comes from a background where the police or law enforcement is already an inimical force that you experience in your community when you're not out in the woods. So I think we're basically inheriting the worst case scenario of bureaucratizing access to mushrooms on the California coast. But that is not to say that I think the solution is complete and total free for all that everyone should pick as many mushrooms as they want all the time, because there are definitely downsides to trampling, to littering....when there are this many people involved and who like it and can do it this often.

Ayana Young  Well, let's say that there is some type of better boundaries around mushroom hunting, and maybe if we're not taking as many mushrooms from the forest commercially, then that leaves this gap of like, well, how are we filling this need for mushrooms, whether it's in medicine or for edibles. And I know that a lot of people have turned to growing mushrooms, similar with the herbal market. Like with the United Plant Savers, a lot of what they say is like, cultivate these plants. Like, don't go out into the woods and strip the last goldenseal plants. Grow them. And so then I think, Okay, well, let's think about growing mushrooms for medicinal and edible purposes, but I know a lot of the ways that mushrooms are grown are in basements or indoors and they're growing on straw, whether that's organic or not, or coffee grounds. And it seems, in a way, I like that, but then in a way, I think, wow, what are we losing when we're using these mushrooms for medicine or for food when they're grown without soil, without the symbiotic relationships of the forest and without natural light. And I just wanted to kind of hear your take on that. I haven't heard people really speak to what is lost when we're consuming indoor mushrooms rather than wild mushrooms.

Christian Schwarz  Yeah. So I will start by saying that this is a little bit out of my wheelhouse because I'm not a huge cultivator, and I don't know very much about medicinal mushrooms, but I do have some insight into this, and I guess I could boil it down to saying, "Yes/And." There is no reason to do only one or the other or to even think that one is more preferable. There's certainly mushrooms that from a gourmet perspective, like, how do they taste? What is the texture like? They appear to be totally cultivatable at huge scales without losing almost anything. The sacrobic fungi, so a lot of the oyster mushrooms, the king oysters, the Agaricus that are cultivated out of the wild, are easily brought into a human setting without apparently losing much at all. And for those, you should cultivate them. Then there are those that are not cultivatable. You can't really cultivate a king bolet. You can never cultivate a chanterelle without growing a forest for it to live in. These are inherently dependent on ecosystem context. And for those, not only is it not an option, I just don't think that that's what people are looking for. Especially with medicinals, there is some spiritual, non material, difficult to describe aspect of the forest being imbued in the potency of that fungus to which I can't really speak. It is not something that I spend a lot of time thinking about. But I don't think those people would accept the equivalency between all medicinal mushrooms being cultivated versus all medicinal mushrooms being harvested from the wild. I think there's probably room for a middle ground. 

And another important thing to remember is that when harvesting mushrooms, they are not like harvesting a golden seal. They're just the sexual reproductive of the life cycle, and in many cases, they're quite sustainably harvestable without impacting the longevity or the population dynamics of the species or the population in that spot. So they are much more tolerant, more robust than plants are of that kind of extraction, but that doesn't mean they're bulletproof. That doesn't mean they're impervious, and we still have to think about and especially build cultural accountability between people who harvest mushrooms for medicinal purposes or people who harvest mushrooms in larger quantities for commercial purposes. How do you hold each other accountable without invoking bureaucracy wherever possible, or law enforcement, God forbid.

Ayana Young  I'm now wanting to move on to another topic, this debate between invasive versus native fungi, or I can say non native versus native fungi, and implications of certain restoration projects where fungi that are not native to the area are rapidly introduced to a forest ecosystem. And that could be different types of mycorrhizal fungi that's added to soil mixtures to help trees grow faster stronger, but many of these times, they're not native. They're not from that forest that they're going back into. So I'm wondering what threat does the imposition of invasive or non native fungi have on ecosystems across various geographic ranges, and maybe you could speak more specifically to: does it matter that these are introduced into these forest ecosystems?

Christian Schwarz  For starters, I'll say that I can't point to specific examples, because I think the long term consequences of using soil amendments, including mycorrhizal fungi that are not native to a forest are relatively unstudied, or if they are well studied, I have not seen a lot of that research, and that's probably more reflection of my ignorance. But I cannot imagine that it doesn't matter. If you manage to successfully introduce large volumes of a non native mycorrhizal fungus to an ecosystem, you are going to experience consequences because the soil community is complexly interdependent, and fungi are major structures of what lives there, what can live there, what, what the trajectory of that soil succession looks like. 

So I would be extremely wary of doing anything at scale that involves non native introductions, especially if you're using native trees that are sort of hyper local natives. There are very small scale co evolutionary relationships that occur. There can be individual genotypes that are more well adapted to their ecosystem than you know, something from 500 miles away. There is actually research about that. Now I don't know if the differences are enough to worry about. If your biggest priority is reforestation, perhaps the cost benefit there from an ecological perspective, is such that you should use whatever you can to get the forest to regrow whether it's strictly native or not strictly native. So it's not something that I can talk deeply about, but it's something that I think should be talked deeply about by the people who are doing it, and probably should be researched more extensively before it gets widely implemented.

Ayana Young  I absolutely agree with that, and in proximity to this conversation on invasive or non native fungi, I'd like to ask about the recent increase in fungal diseases. Specifically, how is climate change contributing to the rise of fungal pathogens that, say, target crops  or which fungal diseases pose the greatest threat to global or local ecosystems? 

Christian Schwarz  Oh boy, that is probably a question for someone who's a plant pathologist or a climate change ecologist. So I can't talk a lot about the direct links between climate change and the recent increase in fungal pathogens, just because I'm not even close to keeping on top of the situation enough. But something that strikes me as just an example of this, that is very illustrative of what we're going to deal with is the amount of aflatoxins. So this is a fungus called Aspergillus flavus that produces these strongly carcinogenic, padotoxic compounds called aflatoxins that infect stored grain. So like corn in a silo, or peanuts, both of these are staple crops for millions of people, hundreds of millions of people around the world. So it causes these cumulative liver toxic effects, including strongly carcinogenic effects at very low concentrations. And it's already a problem. It is something that government bureaucracies monitor to make sure that the amount of toxin in the public food supply stays below a certain level. But as climate warms, the amount of or the number of places in the world where conditions will be favorable for the growth of these fungi is increasing. Hundreds of millions of more people per year will probably be exposed to higher concentrations of aflatoxin as climate warms and becomes more humid in certain parts of the world.

So I think a study came out recently specifically focused on Europe, and just how much more of Western Europe and Northern Europe that currently doesn't have a high incidence of these aflatoxin concentrations, they're going to have to deal with that in the next 50 years. So more people will be exposed to these toxins. It's already a big problem in the developing world where peanuts are a major staple food source. So these are things that humans are bad at getting their priorities right about because they're diffuse effects and cumulative, long term effects. They're not acute. They're not on our doorstep. They are hard to get the right level of response to without using a lot of sort of disciplined and proactive, preemptive thinking. So I worry a lot about things like that. 

Ayana Young  Yeah, rightfully so and I don't think it's even possible for us to fully imagine, even with our models, what kind of impacts climate change are going to really have in so many ways. I think we can, you know, make some good guesses, but it's, yeah, it's huge. And I was reading a recent article of yours titled "As Temperatures Change What Organisms Move North to California?" And so I'd like to turn towards the topic of biogeographic shifts and what can we learn about climate change in California by looking at, for example, changing and migrating mushroom patterns? And I'm wondering how did changes in fungal distribution affect ecosystem functions at large?

Christian Schwarz  So I would say we are. In kind of our infancy about understanding mushroom biogeography, which unfortunately means that a lot of the effects of climate change on macrofungal biogeography, much less microfungal biogeography, are going to be obscured by the fact that we lost our baseline data. We didn't develop robust enough data sets before the major effects of climate change. Anthropogenic climate change had already gotten well underway, so we're kind of catching it while it's happening, and it's only going to keep changing more dramatically so there's no point in not starting now, I would suggest that we throw our hands up in defeat, but we've already missed a lot of what's changed, and much of it was not climate change directly, but habitat destruction. But compounded together, we see there are fungi showing up in California that — thanks to the efforts of community scientists or citizen scientists or simply people sharing what they see, I don't think would have been detected in real time, or as close to real time as they are now. Things like Amanita terzii, this saprophytic Amanita from the eastern United States appears to have made a massive jump into California just last year. Mushroom called a greengill mushroom that was widely distributed in the American southeast and in the tropics, is creeping northwards in California and actually appears to have reached Canada already. And every year it becomes more common. Every year a new county gets a record that didn't have it before. 

What we can learn from this, I don't think, is at all surprising and I don't think it necessarily helps us respond to climate change. It's just further icing on the cake. We already know that organisms are going to move over the landscape as their environment changes. They simply, I think, add to the urgency of doing what we already know we need to do, which is cut emissions wherever possible and really radically get a handle on our ideas about what sustainability means. So it's not anything counterintuitive, it's not anything surprising. Although individual cases may be interesting, sort of academically or from a biogeographer's narrow standpoint, but as far as their practical lesson or their moral — we already know climate change is deeply impactful on communities of both fungi and their associated plants. So as fungi move, they may bring their host plants with them or they may facilitate the growth of plants in areas where they previously didn't have a compatible partner, or vice versa. As plants move, fungi may be extirpated if they can no longer find a plant that's got suitable environmental conditions for its growth. Both of these directions will occur. You know, we'll get new fungi, we'll get new plants. And we'll also lose fungi. We'll lose plants.

Ayana Young  Well, along the threads of the fungi global environmental change, I'm wondering if there are instances where fungi can actually provide landscapes with increased tolerance to say, drought or salinity, and how are we seeing mycorrhizaes acting as agents of support where plants experience an increase in environmental stressors?

Christian Schwarz  Fungi have always helped plants live in places they could not otherwise live. Probably, since the beginning of fungi, for plants to have access to nutrients, soil nutrients they otherwise wouldn't be able to absorb efficiently enough to maintain, you know, growth and robust populations, they allow for plants to get water they wouldn't be able to efficiently accumulate enough to stay alive in drought environments. And then there are endophytic fungi that act as kind of an extended immune system. They're not mycorrhizal, but they live inside plant cells and may prevent the incursion of other pathogens because that cell is sort of already occupied by a microorganism that is beneficial to its host. 

There are studies that show that fungi help mitigate the toxic effects of salinity on plants. So all of these things happen. There's really no ecosystem in the world where fungi are not a major part of how plants make their living. I think you know the frequently estimated statistic is that 90% of all land plants have some sort of mycorrhizal association, and pretty much all of those cases, it's an important one. It means they can live where they're living, and they can thrive to the degree they're thriving. There's nowhere where it's trivial. 

Ayana Young  Well, thank you, Christian for taking this time with us today and weaving through the world of fungi and if there's anything that you want to end this conversation on, anything that we didn't get to touch on. I'm sure we didn't get to touch on a lo because there's so much to say in regards to fungi, but I just want to give you the space to close out this conversation with whatever feels best.

Christian Schwarz  Sure, I just want to explicitly state that I encourage everyone to download iNaturalist onto their phones, if that's something you have and use, and if you've got the bandwidth for and explore it because it is a place where I really found sort of a community of like minded, aesthetically sensitive, responsive individuals who love biodiversity in and of itself whether or not it's edible or practically useful in any way. It's just a community of people who like that. We're surrounded by this teeming multitude of organisms here on Planet Earth. So please join in that if you feel like it, and come meet the rest of us. 

And for those of you who don't feel like that's the way into biodiversity or the way into fungi, for you, I would stress the value of finding a community of people. It is in the long run where I've found eventually — it took me a long time to realize this — the real value is getting other people to help you deepen your connection to these organisms and to find each other to build communities, because those communities end up being useful for things that have nothing to do with what they were originally organized for. They become your social network in times of distress and trouble and illness and community organizing towards other causes. So find your nucleus, whatever it is, whether it's fungi or some other group of organisms, and keep those ties strong for when they're needed in other regards. 

Ayana Young  Well, thank you, Christian for your time. And yeah, for those of you who want to dive in more to the mushrooms of the redwood coast, pick up Christian's book. It's definitely worth it.

Christian Schwarz  Thanks so much, Ayana.

Ayana Young  Thank you for listening to another episode of For The Wild Podcast. I'm Ayana young. The music you heard today was Grant Earl LaValley and Dimples. I'd like to thank our podcast production team, Aiden McCray, Andrew Storrs, Carter Lou McElroy, Francesca Glaspell, Hannah Wilton, Eryn Wise, Vera Lummi, Erica Ekrem, and Melanie Younger.