Hidden fungi could be the key to help protect saguaro cactuses in a warmer future

We all know that water is our most precious resource here in the desert. And, as climate change makes it hotter and drier here in the Sonoran Desert, it’s becoming even more essential. But, researchers are learning a tiny fungi just might be able to help.

Mycorrhizal fungi are a vital part of ecosystems around the world — including to climate-threatened saguaros here in the Sonoran Desert. Researchers are trying to find out if they could be a key in helping protect the iconic cactuses in a warmer future.

Wyatt Myskow covers the Southwest for Inside Climate News. He spoke more with The Show about these hidden little fungi.

Amber Victoria Singer/KJZZ

Full conversation

WYATT MYSKOW: Despite you not being able to see them, mycorrhizal fungi are incredibly vital parts of ecosystems around the world and including in the Sonoran Desert, and they form what we call symbiotic relationships with just about every type of land plant.

And the way one of the researchers described them was as a highway, they exchange water and nutrients like nitrogen and phosphorus for carbon that they use to continuing to expand out this highway system that grows out their roots even further and even connects them to other species, a kind of Across a whole ecosystem, a whole region of plants and fungi and all sorts of things.

And so they're incredibly important for plants being able to get the nutrients they need, helps keep them more resilient, helps kind of stabilize them in the ground again, they kind of extend that root system. And they also, for climate change, they sequester over 13 billion tons of carbon, and that carbon, if it, you know, wasn't being sequestered would otherwise go towards warming of the climate further, which obviously would not be ideal for us or for those plants and of course the fungi themselves as well.

LAUREN GILGER: Right. And explain for us a little bit about how it is that this fungi works in particular for saguaros, which we know are threatened. They seem to maybe act as a lesson or some sort of way of protecting these saguaros, right?

MYSKOW: Yeah, that's what the researchers that I worked with were trying to find out. We know that there are mycorrhizal fungi in the soils next to saguaros oftentimes. The question is just how important though are they? And that's what they were trying to find out. Saguaros, as we know, are struggling. You have climate change causing hotter and drier summers, you know, saguaros are really resilient creatures. They last centuries, right? You don't live that long unless you are resilient in the wild, right?

But climate change is really kind of throwing a wrench in that and just kind of making things are hard for them to survive and to reproduce. And the hope is if we can understand how these fungi work with these saguaros. We can understand then what kind of conditions they need to support each other and recognize, OK, if we protect these soils better than we are currently, how could that maybe help saguaros, right, this iconic species continue to thrive and live in Arizona and across the Southwest. That way we don't lose more of this iconic species.

GILGER: Yeah, which is a real concern right now. So you went along with these researchers here at Saguaro National Park, as you mentioned. Tell us about what that was like, like how did they find this stuff in the soil. This is, this is hidden as you say, but they're using some kind of intense technology to figure this out.

MYSKOW: Yeah, it's somewhat intense, but also not really. I mean, you know, like I said, this fungi is found pretty much everywhere. And so to get the samples themselves, the researchers I was with or the Society for the Protection of Underground Networks, they're a scientific organization, nonprofit founded to map these fungal networks kind of around the world, and they do a ton of these trips to go to under sampled areas and collect these types of samples. They've done it here, they've done Kazakhstan, they've done it elsewhere.

And they also take existing data and essentially use AI and, you know, modern technology to map out what do we know, what do we not know, where are these networks, how do they work, all that kind of stuff.

And so I joined them at the park this spring in March to just spend a day with them to see how it was done. And you know, it's surprisingly simple. I mean, to collecting the samples, all they did was, you know, they, they went out to the field, then they took, you know, basically a, a metal cylinder, a rubber mallet, a plastic bag, and they, you know, found saguaros and they got on their hands and knees and, you know, hammered that metal sphere, essentially that metal cylinder, into the ground, pulled out the dirt and put it in a plastic bag.

And then that bag is sent to back to the research lab to be analyzed to figure out, OK, what exact fungi are in this soil and what can we learn about it? How does it maybe different from others, how is it maybe similar? And kind of beginning to get an understanding of how this stuff works.

What was interesting though, it may be more kind of advanced technology that's a little more complex, was they had, you know, on their iPhones, you know, LiDAR technology, essentially they found saguaro they took a sample of, they wanted to get information on what kind of saguaro was this, you know, they wanted a diverse collection of samples from all different age groups, or how do these ones survive longer than ones that don't.

So they're taking all these samples, but they want to collect, OK, what do these saguaros look like, right? And they could take photos, they could maybe you know write down in their notes what it looks like. But they use their phones and they use this LiDAR to essentially scan them and right there on the spot in a matter of minutes, it was creating on their phone and adding it to their database, these like 3D images of the saguaros and it, you know, it was able to calculate without them doing measurements themselves, how tall it was, how many arms it have, which then gives you kind of a rough estimate of how old it is.

GILGER: So this is threatened in another way though, right? Like researchers need basically kind of untouched soil, untouched ecosystems to do this research, right, to take those samples to understand how this is working and how it might assist saguaros in the future. But that kind of untouched landscape is harder to find these days, especially as we're looking at massive cuts from the Trump administration, right?

MYSKOW: Correct. You know, most people, I mean, we're all familiar with national parks. If you live in Arizona, you've been to the Grand Canyon, you've probably been to Saguaro, you've maybe been to Petrified Forest and other protected areas like national monuments, and you know, those places have a real recreational benefit, right for us to, you know, go and hike there, enjoy it.

It also, of course, has benefits for wildlife and a little bit of an unsung use of national parks and protected areas like these is for research purposes, right? Because they are untouched, because they are protected, you got to get a good idea of what an ecosystem looks like when it is not being disrupted by humans, essentially, right? We're not developing there, we're not building houses, we're not driving all over it. We are leaving it pretty much the way it was. But like you said, that's disappearing in the modern world generally.

So these national parks and places like them are incredibly important generally for understanding what are we losing, what could be lost if we continue doing this stuff, and also just understanding what does an ecosystem look like before humans begin to mess with it. And with the Trump administration, we're already seeing, you know, mass layoffs at parks, a lot of that, you know, being kind of done in the scientific research realms of those parks, and it's going to make it harder to be able to do this type of work.

And I mean, one thing to be clear, I mean, Saguaro National Park is not going to be dismantled and sold off most likely under the current Trump administration, but it does have a lot less staff and those staff are incredibly important for allowing these researchers to be able to come in and do this type of research and maybe be able to add to this research. I mean some of the best saguaro experts you'll find work under the Interior Department. You know, and then that's not even getting into national monuments, which are also incredibly important for doing this type of research, but have been threatened by the Trump administration with the downsides and with dismantling. it's something they've already tried to do in the past.

We may know that it's gonna happen again. It's just kind of a matter of when and there's real concerns over, I mean, for many reasons, right, it's a place that people can no longer go to and recreate, it means that, you know, a great wildlife corridor no longer exists, but it also means that research like this to study something that we really don't know much about disappears, as you know, one of the researchers told me once it's gone and deleted, it's gone. And the thing that upset him and this is quoting him, ”if they're gone before we actually know what's there, we have no idea what we lost.” And that's really important.

And one thing I'll stress here too on this is when we talk about climate change, you know, it's often an assumption, and it is a true assumption that fossil fuels are obviously a major driver of our climate crisis. But another kind of unsung factor that gets less attention is the loss of biodiversity. You know, species like these fungi and the species they then kind of in turn help grow and support are incredibly important for sequestering carbon, for creating healthy ecosystems that in turn make our planet a healthier place.