Alumni: Kathleen Treseder On the Ubiquity of Fungi

Kathleen Treseder

On the Ubiquity of Fungi

For Kathleen Treseder, HBS’94, the launching pad for her career in science and research was Borneo, the giant, rugged island in Southeast Asia’s Malay Archipelago.

ASalt Lake City native and a first-generation college graduate, she didn’t know that universities did research. She soon found out otherwise.

On a field trip together with plant ecologist Jim Ehleringer, he asked her if she wanted to go to graduate school. “You’ll need field experience,” he said. “Is there a field site you can go to? Borneo?” He told her to ask Diane (Dinah) Davidson, who is now an SBS professor emerita.

“So I prepared a whole speech on why I wanted to go,” says Treseder, thinking she was going to need to sell herself, “and I didn’t have a chance to say it to her.” Davidson just signed her up right out of the gate.

It was the first time Treseder had traveled by herself away from the University, and it proved to be transformative for her. “It was a series of change encounters. Without Borneo

my life would have looked much different.” It was the work she did there that ended up in her honors thesis which in turn was published on the cover of the prestigious journal Nature.

Not at all bad for an undergraduate researcher.

Now a professor of Biology at University of California, Irvine, Treseder has never gotten very far from that first impetus at the School of Biological Sciences to do research. Today she and her lab address the role of fungi in mediating ecosystem responses to global change. “Our overarching goal is to improve predictions of future trajectories of global change,” she says, “by incorporating feedbacks governed by fungi.”

When most of us think of fungi, mushrooms often leap to mind. But fungi are everywhere, and whole phyla of them are still being discovered. She started studying other kinds of fungi during grad school at Stanford. (“I had to learn all that, on the fly.”) She was also quick to learn that her subject matter is largely invisible to the naked eye. Ninety percent of the biomass of fungi is micro-scale, making them unseen and invisible players in the world. “Every once in a while, fungi will make mushrooms,” she says, which is like the “apple of a tree.”

In terms of climate, and climate change, fungi are real players, and the Treseder lab focuses on their production and storage of carbon (C) to corroborate that. It turns out that fungi release ten times more carbon dioxide (CO2) than humans do. “That means if fungi change [there’s] major ecological change,” she says. But because this happens at a microscopic level it’s been very hard to study.

When you look at rich, dark, soil, you are seeing a lot of carbon—most of which is from fungi or bacteria that have died, which is a good thing. “It adds up to a lot,” she says. There’s “twice as much carbon in the soil as in the atmosphere, and much of that is in [fungi].”

For fieldwork, Treseder chooses ecosystems that are in danger from fires–for example, coastal sage scrub, only five percent of which is intact–and how fungi respond to depletion. She has also studied cloud forests in Costa Rica as well as boreal forests in Alaska that are warming faster than others. Are these big changes in carbon in various sites due to fungi? Very possibly.

The role the ubiquitous fungi plays in climate change is so paradoxical, so mind-bending and so large that it requires a massive database. While the research requires thinking on the molecular level about the individual bonds that are breaking down, it is ultimately concerned with how much CO2 is entering the atmosphere globally. We are always, “taking the research to a new level: trying to put the research in our lab and into a broader context. Whatever we find in our lab, I want to know, is this something that occurs broadly?”

The best way to approach this problem is to construct databases with all the research around the globe and to incorporate them into computer simulations of the earth’s climate called Earth System Models. The models include everything we know about how climate behaves, Treseder says, attempting to answer questions such as, What if the fungi reduces the CO2 by this amount? How will that affect the climate?

“It all relies on hands-on work on the ecosystem by lab teams,” says Treseder. In addition to testing foundational ideas about fungal ecology, the team is also looking into whether fungi that adapt to more stressful environments in turn lose their ability to grow well under favorable conditions. Team science is not just talked about in her lab, but it’s actively engaged. It is a science unto itself.

While Treseder’s research journey since graduating from the U has been absorbing, it hasn’t been so absorbing and demanding as to exclude other ambitions. It has, however, informed her other interests which includes ecological policy and removing barriers for women in science. “Local officials can really change your life and they need access to science,” she says.

It was an extension of this activism that led her to declare her own candidacy earlier this year for Irvine City Council on a green platform.

This trifecta of research, activism, and politics is, of course, all informed by Kathleen Treseder’s identity as a biologist that germinated at the University of Utah and threaded through her transformative time in Borneo years ago.

And while the Treseder lab shutdown for half a year because of the pandemic, and her lab members were sent home to do field research, fortunately… fungi are everywhere.

“If fungi change, there’s major ecological change.”

You can read an expanded profile of Kathleen Treseder on our website at biology.utah.edu