Ecologist Catherine Zabinski discusses plants and microbes

What happens with plants beneath the surface is a mystery for most, but not for Catherine Zabinski, a professor in the department of Land Resources and Environmental Sciences at MSU. Studying the root systems of plants presents a unique challenge for researchers, as they have to be disturbed in order to be looked at, which changes the nature of studies.

Zabinski delivered her lecture, “Roots and microbes: The world beneath our feet,” at the Museum of the Rockies on Wednesday, April 12. She was the final speaker in the Provost’s Distinguished Lecture Series. Zabinski began by pointing out how important plants are to the world: “They play a lot of important roles for us culturally, economically.”

From an ecological standpoint, plants are vital because they perform photosynthesis, converting the sun’s energy into a form that is useful within the ecosystem. “That’s the basis of all of our ecosystem functions,” Zabinski said. “It all starts with the plants being able to capture sunlight.”

Zabinski’s research focuses on plant root systems and soil processes and part of her research is about the relationship between plants and the microbes that live within root systems. She discussed her research on mycorrhizal fungi, which form a mutually beneficial relationship with the plants that hosts them. Zabinski showed photos of root systems to display their immense size and complexity. She also showed photos of various microorganisms that can make their homes in root systems.

At MSU, one of Zabinski’s studies focused on spotted knapweed, a noxious weed that has caused serious problems for grasslands across the West. The study focused on mycorrhizae in the plant. The original hypothesis was that knapweed is not mycorrhizal, which was of interest because figuring out why knapweed is so invasive has major implications for preventing its spread. The research found that knapweed was indeed mycorrhizal, which did not explain why knapweed is so invasive. Competition studies were done where knapweed was planted next to other plants and the root systems were then studied. They found that with the mycorrhizal activity, carbon was being stolen by the spotted knapweed from the other plants, allowing it to grow faster and choke out grasses.

Zabinski also discussed her research on plants in Yellowstone National Park that survive in extremely hot soil. Additionally, she touched on agriculture and how farming can affect microbial communities.

To conclude, Zabinski pointed out that studying this part of the ecosystem is vital for agriculture and food systems, restoration and many elements of the natural world. She noted that because microbial communities are so complex, there is not a reliable way to add microbes to the soil to make it more productive.