"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.