Bison will once again feast on the grasslands of northern Anoka County this summer as scientists continue to study what role the animals may play in helping save the oak savanna, one of Minnesota's most threatened ecosystems.
The herd will arrive in late May and stay through the summer at Cedar Creek Ecosystem Science Reserve, a University of Minnesota research station that straddles Anoka and Isanti counties. Weekly chances for the public to glimpse the herd begin June 1.
It marks the second straight year for bison to be hauled onto 200 acres near East Bethel for a seasonal stay at one of the largest swaths of oak savanna left in the state. Scientists say the project could uncover a new strategy to maintain the vanishing Midwest ecosystem.
Since the 1960s, researchers at Cedar Creek have studied how to best preserve and restore the oak savanna. The delicate mix of oak trees and prairies once covered huge tracts of the Midwest but has largely been lost to croplands, pasture and development.
Ongoing research has been rooted in prescribed burns at Cedar Creek, one of the best-studied ecosystems in the world. Scientists there have found that fire helps keep woody plants from crowding out prairie grasses and flowers.
But the blazes, fueled by the robust grasses, also have made it tough for oak seedlings to survive. That's why U researchers introduced a herd of bison last year, bringing the animals back to the Anoka County area for the first time in more than a century.
The bison project has largely been funded by the state's Environment and Natural Resources Trust Fund, and scientists say they hope to keep the work going for years to come.
Researchers wonder if bison have been the missing piece that oak savannas need to flourish. The large grazers feed on the very grasses that fuel the fires. Grazing could make those needed burns less intense, giving tiny oaks a better shot.
