As an expert in microbial ecology, Krista McGuire's research has taken her from the Guyana rain forest to Alaska's boreal forests. She studies the role of fungi in critical environmental issues such as global climate change, plant extinction, and deforestation. This year McGuire joins Barnard College as an assistant professor of biological sciences. "Barnard seemed like the perfect fit because it has a liberal arts curriculum, plus all the [research] resources of Columbia," she says. "It's kind of the best of all worlds." For the fall semester McGuire will teach an upper level research seminar in microbiology, guide students in writing research papers on topics such as how microbes function in natural ecosystems, impact humans and animals, and relate to global climate change. In the spring, she'll be teaching a microbiology lecture and laboratory before heading to Southeast Asia for a summer of research.
Her work, which garnered a Kearney Foundation grant for research in California ecosystems, and a National Science Foundation doctoral dissertation improvement grant, focuses on the interrelationship of fungi and plants in forests and the process of nutrient cycling between them. The planet's extremely diverse fungi population—there are almost two million species, only five percent of which have been described by scientists—plays a bigger role in forest ecology than most people realize. Many fungi live off dead plant matter, and in the process of consuming and breaking down this matter, they cycle crucial nutrients back to the ecosystem's living plants.
"One of the main questions I'm interested in is: When we lose plant species from the forest, how does that impact how many fungi we have in the forest and how quickly they cycle the nutrients from dead plant matter back to plants?" McGuire says. "As most people know, we're losing the rain forests, and a great number of plant species, at a really extreme rate. But we don't yet know the impact of this loss on fungi and how the nutrients will be cycled."
Growing up in New Jersey not far from the Appalachian Trail, Krista McGuire became fascinated with fungi at an early age. "In high school I started collecting mushrooms, and identifying them. I joined the mushroom club," she says. The interest led her to study biology as an undergraduate at Muhlenberg College in Pennsylvania, and, during a course in Costa Rica, she says she became "enraptured" with the rain forest. Today, after earning a PhD in ecology and evolutionary biology from the University of Michigan, Ann Arbor, McGuire has tied her two loves together; she's an expert in microbial ecology with a focus on tropical rain forests.
A review paper she is currently revising looks at the microbial community on a global level—how many and what kinds of species of fungi and bacteria exist—to inform mathematical models, which can be used to predict how processes of nutrient cycling will shift with global change. Fungi drive the cycling of nutrients throughout the planet, McGuire says, are major regulators of the carbon and nitrogen cycle, key components of many of the greenhouse gasses responsible for worldwide climate change.
"We still don't know all the species that exist in the world and what they do. Since we're losing the rain forest so rapidly, it's important that we figure out these complex links … figure out how to mitigate the effects of global change, which are mostly being driven by human activity, and also to predict how things will change."