Long-term research by GVSU expert on restoring rare ecosystem's biodiversity nears completion

A Grand Valley ecology expert working on a long-term study with a land conservancy organization to restore biodiversity to rare oak savanna ecosystems is nearing a milestone in her research to assess the effectiveness of the tactics.

Priscilla Nyamai, associate professor of natural resources management, has been carrying out a five-year research project at two Kent County nature preserves to see if efforts such as prescribed burns and reducing the tree canopy can help restore the specific characteristics of oak savannas.

The ultimate goal, Nyamai said, is that the restoration tactics expand the pockets of oak savannas in those areas and help boost the resilience of the ecosystem to climate change.

"We need to create diversity in species so we don’t lose these natural communities," Nyamai said.

Disruptions to the natural fire cycle that maintained the forests and intense land use are key contributors to the ecological changes that have altered the savannas, Nyamai said.

"Because of these changes, the oaks have gotten company with broad-leafed tree species," Nyamai said.

The result has been a high density of trees in a relatively small area, which creates a canopy that blocks light, Nyamai said. That has led to the diminishment of the wildflowers and other plant life that are typical for an oak savanna, along with detrimental effects on such organisms as pollinators.

Nyamai said she set up a research plan for the two preserves, B.D. White Nature Preserve near Lowell and Brower Lake Nature Preserve near Rockford. She is entering the final year of her planned research, which has involved a rotation of prescribed burning one year and data collection the next.

Another crucial tactic used by Nyamai is "girdling," which helps reduce the canopy by killing the non-oak trees that have overtaken the ecosystem, but letting them stand. These standing dead trees, called snags, continue to provide habitat for birds and insects, Nyamai said.

Nyamai has set up 60 plots to monitor for data, such as soil conditions and vegetation changes. She said she will do a full assessment of restoration treatment efforts after this final collection of data. 

Justin Heslinga, stewardship director for the Land Conservancy of West Michigan, praised the collaboration with Nyamai in working to restore this ecosystem. He said because Nyamai is conducting a controlled study, the conservancy's land management efforts and the research can continue simultaneously.

"It's a phenomenal partnership," Heslinga said. "Rarely do managers and researchers align in such an organic way. We're doing the management we still need to do on the ground and Priscilla is doing research in a robust way."

He said from a visual standpoint, the restoration efforts seem to be heading in the right direction, with "some of that savanna character reemerging."

That is encouraging because the ecosystem, which is home to such species as Karner Blue butterflies and wild lupine, is special and threatened, Heslinga said.

"It is one of the rarest ecosystems in the state. If it was an animal it would certainly be on the endangered species list," Heslinga said. "When we have a chance, we take the opportunities to manage and restore them back to health."