There's still much we don't know about fungi. The University of Wisconsin is recruiting citizens to help

CATHY WURZER: Got some time? How about being a citizen scientist and sending tree roots to a lab at the University of Wisconsin? Why? It has to do with fungi, yeasts and molds and even mushrooms. Fungi are miraculous. By breaking down rock and turning it into soil, they make it possible for plants to move onto land-- well, about 500 million years ago. And they've been forming fascinating relationships with plants and animals ever since.

Take forests, for example, where networks of fungi connect to tree roots and trade nutrients back and forth. These networks have gotten much more attention in recent years, but there's still so much we don't know. So scientists at the University of Wisconsin are asking people in states along the Mississippi River for some help. PhD candidate Kathleen Thompson with the Forest Fungi Project is on the line to tell us more. Hey, Kathleen. How are you?

KATHLEEN THOMPSON: I'm great. Thank you so much for having me. It's an honor to be here.

CATHY WURZER: This is pretty cool stuff. So you want folks to send tree roots in the mail. OK. And what are you hoping to learn?

KATHLEEN THOMPSON: Yeah, absolutely. That's a great question. Well, first and foremost, one of the things that we aim to do with this project is engage the broader community in the process of scientific research and show them that sometimes, it can be just as simple as going out into your backyard or a nearby forested area to get involved. But also, we're trying to generate data that will address some important and pressing ecological questions, one of those being related to what we call fungal biogeography, or put more simply, what fungi are where. So plants and animals have centuries of this type of work and data, but fungi really lack those types of records over time.

CATHY WURZER: Wow. OK. So but fungi-- fungi-- excuse me-- how in the world did you manage to start this project? I mean, it wouldn't be something that would naturally pop up on someone's radar screen.

KATHLEEN THOMPSON: Yeah, totally. Additionally as well, you can pronounce it "fun-gee" or "fun-gi", however you wish. So this project was launched in 2015 out of Rick Lankau's lab at the University of Wisconsin, Madison. And his lab has historically been interested in plant-microbe interactions, but also, seeing that to answer some of these big ecological questions involving fungi, we really lack some of these baseline records. So it's certainly a lot more straightforward, and perhaps a lot more meaningful, than sending a graduate student out to tour every state along the Eastern United States to collect samples at a variety of locations. This is a great crowdsourcing opportunity to get everybody involved to be sending samples in to gather this kind of information to be asking bigger questions.

CATHY WURZER: I'm curious about the networks that fungi communicate with, trees and other organisms around them. Do we know how they do that at all?

KATHLEEN THOMPSON: Yeah, that's a really excellent question. And there's certainly a lot that we still don't know but a lot that we do know. The type of fungi that it seems like you're talking about, the networks underground that are connecting trees and participating in this type of communication that's receiving a lot of attention these days is called mycorrhizal fungi. So "myco" means fungus, and "rhizal" means root. So it's essentially fungi that are in a close association with tree roots and most plant roots, for that matter, as well.

And oftentimes, what's happening is fungi are very much like animals in the way that they can't make their own food like plants can through photosynthesis. So fungi are receiving carbon made from photosynthesis from plants in these interactions. And in return, they're giving plants things like access to nutrients such as nitrogen and phosphorus, which are oftentimes limiting for plants, or maybe it's access to water or protection from pathogens, a variety of sources. But instead of both finding their own ways to do this, they've gotten into this close association where they can utilize what they're best at and trade for services that they need a little bit more help with.

CATHY WURZER: I love that, trading for services. [LAUGHS] It sounds so human.

OK. So if someone's listening and wants to participate in being maybe a citizen scientist, how do they start?

KATHLEEN THOMPSON: Great question. So I would even navigate you all to the website, which is forest-- let me make sure I've got it right here-- forestfungi.russell.whisc.edu for a full picture of what this looks like. But really, what you need is some kind of device with GPS capabilities, which could be your smartphone, which a lot of people have, some kind of small shovel like a hand trowel, some Ziploc bags, and a marker for labeling. And to get involved, the most challenging and very important aspect is making sure you have permission to collect wherever your place of interest is. And if you have issues with that, be sure to reach out to us, and we'd be happy to make sure that you have all of the appropriate permissions in place.

But once that's in place, all you need to do is visited this forested area, somewhere that doesn't have a mowed, highly manicured lawn, and find a tree that has green leaves that you want to sample from. Once you get there, you record your GPS coordinates. You dig a small hole at the base of the tree and collect tree roots. You put them in your bag. You label it with your name, the GPS coordinates, and the date, and you're off to sampling as many trees as you wish, as many as you'd like to collect that day. And once you have your samples, then you can contact us, and we can figure out a plan to get them shipped to us.

CATHY WURZER: Ah, cool. But gosh, we're running out of time. Very-- well, I shouldn't say very few, but there are still some green trees around the Twin Cities metro area, Minneapolis-Saint Paul. What are fungi doing during the fall? Are they getting ready to just kind of relax and go into hibernation, as do so many other organisms in the winter?

KATHLEEN THOMPSON: Yeah, that's an excellent question, and it probably depends on what type of fungi we're talking about. But fall can actually be a pretty active time for a lot of fungi. So they've received a lot of sugars from trees over the big summer growing season, so they're actually pretty active right now. But coming into winter and as trees lose their leaves, some of these fungi that are closely associated with trees aren't receiving as many sugars as they were before. And so they do, over winter, oftentimes reduce their overall growth. And they're sitting, waiting for conditions to improve into the next growing season.

And a lot of people may have noticed if you're in forests a lot fall is a great time to see mushrooms or fungal fruiting bodies. So mostly, what they're doing is gathering carbon and sugars over the year to then create these big, fantastic displays of mushrooms which are involved in their reproductive efforts in the fall. And then they're continuing that cycle into next year.

CATHY WURZER: I'm listening to you, Kathleen, and your voice just sounds like you are so into this and so excited, which I love that. I love that. I love anybody who's got passion for whatever it is. So do you have a favorite type of fungi, one that you can find in the forest, perhaps?

KATHLEEN THOMPSON: Oh, yes, good question. And I'm glad my enthusiasm is coming through here. But gosh, I'm such a big fan of everything. But one particular interesting thing about this project has been-- since we're sequencing these roots, that's one thing, is after you send in, one of the things we're doing is we are extracting DNA from these roots and then sequencing them. So we can see, even if in small traces, a lot of fungi that are present in these roots that you might not see in these forested areas, either, whether they don't create fruiting bodies above ground or they're just really hard to find.

So one thing that's exciting for me is seeing all the different species of truffles that show up. We actually have more than 50 different species of truffles that are native to the Midwest and present in the Midwest. So oftentimes, they make little underground fruiting bodies. And so unless you're specifically looking for them and you get there at the right time, you're not going to find them. So seeing them pop up on the sequencing results is always really interesting.

But our lab has also found some really interesting results with a type of fungi that's considered an endophyte, so "endo" meaning within and "phyte" meaning plant. So they grow within plants, but they don't create your normal disease symptoms like a plant pathogen or something might. But this particular genus, cladosporium, we're actually finding could be involved in allowing trees to persist in areas that are hotter and drier than a lot of the rest of their range. So it's possible that these fungi are helping plants persist in areas at the edge of their range that have different conditions than what they're used to and could help them persist as our forests continue to change into the future as well.

CATHY WURZER: Oh, my gosh. That is interesting. I bet research on that would be actually quite beneficial moving into, as you say, our changing climate. Getting back to the truffles, because I love truffles-- so where can one find these little buggers?

KATHLEEN THOMPSON: Oh, you can find them in a lot of places. So I would say if you're aiming for them, find areas with conifers like pine trees or areas that have forests that have a lot of oaks and hickories. So they tend to be a type of fungi called ectomycorrhizal fungi. And if we break that word apart, we're getting into-- you might remember that "mycorrhizal" word I just said, myco fungus, rhizal root. But ecto, it's a particular type of mycorrhizal fungi, if you will. And they associate with oaks and hickories and coniferous trees and such.

So in the fall-- we're probably still in the season, maybe a little past-- but if you go to areas around those trees and you gently scrape the top of the soil, you may see little round truffles. They're little round fungal masses, little fungal balls, if you will, that are popping up out of the soil, just under the soil surface, really.

CATHY WURZER: Cool Kathleen, it's been fun. Thank you so much, and best of luck.

KATHLEEN THOMPSON: Well, thank you so much for having us. We appreciate it.

CATHY WURZER: Kathleen Thompson is a PhD candidate at the University of Wisconsin. In case you didn't get the instructions as to the Ziploc bags and the Sharpies and where to dig the roots and all that, we'll put this on the website. We'll actually put it as part of our podcast, Minnesota Now, wherever you get your podcasts so you can participate in this citizen scientist project. Oh, the things you'll learn here on Minnesota Now, right?

So thank you for joining us. We appreciate it. Have yourselves a good rest of the day.