Footsteps crunch fallen leaves as University of Michigan School for Environment and Sustainability (SEAS) Professor Inés Ibáñez’s research team finds their trees.

A forest ecologist and tree demographer, Ibáñez has been conducting research throughout the University of Michigan Biological Station’s (UMBS) 11,000 acres for 16 years.

This fall she’s setting up an experiment—an eight-month “tracer” study—that targets an increasingly important question: What happens underground during the winter and how does it impact summer growth? This project aims to learn if trees take up nutrients, specifically nitrogen, in the winter.

That’s where the decomposing leaves come into play.

“Nitrogen is the most limited resource that plants have because it’s not in the soil. It’s coming from the decomposition of organic matter,” Ibáñez said. “We think if plants are taking any nutrients, it’s going to be nitrogen.”

On Tuesday, Oct. 15, Ibáñez, a co-instructor of the Forest Ecosystems course at UMBS, got down on her hands and knees on the forest floor to insert resin strips into the soil next to the chosen trees marked with orange flags.

She and the U-M undergraduate and graduate student researchers on her team set up this experiment in two different types of forest at the campus in northern Michigan using oak, pine and maple trees. They repeated this same process in southern Michigan near Ann Arbor.

They’ll split up to visit each tree once a month through June 2025, removing one resin strip each month.

Read the full story in on the UMBS website.