The removal of more than 100 diseased oak trees at Myre-Big Island State Park will allow restoration of rare prairie oak savanna, according to the Minnesota Department of Natural Resources.
“Oak savanna was once one of the most common vegetation types in the Midwest,” said Molly Tranel-Nelson, DNR regional resource management specialist. “It was the transitional area between prairies and forests, once covering about 10 percent of the state. Savanna was dominated by scattered oak trees, standing in a diverse mix of native grasses and flowering plants.”
Frequent fires kept brush and less desirable trees at bay, while the fire-tolerant oaks and prairie plants flourished.
Since statehood much of the savanna once common to south-central Minnesota was cleared for agricultural use. The control of fire allowed unmanaged oak savannas to become choked with vegetation.
“Today oak savanna is considered one of the rarest plant communities on earth,” Tranel-Nelson said. Birds such as the eastern whip-poor-will, red-headed woodpecker and northern flicker, flourish in oak savanna.
Park Manager Jerry Katzenmeyer said many of the oaks at Myre-Big Island State Park are being hit by bur oak blight, two-lined chestnut bore or oak wilt.
“While it may be surprising to see large, mature oaks being cut, the reality is that by harvesting the dying oaks, we have a better chance of saving the remaining trees,” he said.
Oaks in the park will be harvested through the winter. Visitors will see stumps and brush disturbance until the grasses begin to fill in, next summer.
“Restoring oak savanna has long been a goal at the park,” Katzenmeyer said. “Removing the dying trees enables us to restore a landscape that existed when the area was first settled.”
He added that the harvest will not occur on Big Island since it is dominated by maple and basswood rather than oaks.
Prevention will always be the easier and less-costly option, according to DNR forestry specialist Brian Schwingle.
“Oak wilt is a concern for the southern two-thirds of the state, but its spread is also easily prevented,” Schwingle said.
Schwingle says Minnesotans can prevent the spread of oak wilt by:
Landowners with concerns about their oak trees can visit mndnr.gov/treecare/forest_health.