Oak savannah heads back to nature

One square foot at a time, undoing decades of environmental damage and neglect, what might soon become Minnesota's largest expanse of oak savanna is slowly re-emerging on the bluffs above Lake Edith in Afton.

Belwin Conservancy has 1,338 acres of land that holds a wide range of plants and animals. The nonprofit group attracts thousands of schoolchildren each year, and its main purpose is education and preservation.

Restoring the 100-acre oak savanna -- the rarest type of ecosystem in America -- has became part of the group's mission, said Steve Hobbs, conservancy executive director.

There are many kinds of savannas in the world -- the Serengeti in Africa is the most famous -- but in the Midwest, the oak savanna took dominance. The savannas are made up of scattered white or bur oaks with canopies that allow grasses and other flora to get the sunlight they need.

In Minnesota, oak savannas were once 10 percent of the state's ecosystems. They marked the transition from the woodlands to the east and the plains to the west. But after European settlement, the oak savannas began disappearing because of grazing and the ending of controlled fires Indians used to restore the grasses and keep invasive species like buckthorn at bay.

Now, less than one-tenth of 1 percent of oak savannas remain.

When Belwin's project began, the work was daunting. Thick undergrowth was a veritable jungle that needed to be hacked through.

Even with help from the Sentencing to Serve program and the Minnesota Conservation Corps, it was slow going at first. But grants of about $120,000 over two years from the DNR, along with a partnership with District Energy of St. Paul to carry away the tons of debris for biofuel, accelerated the effort.

From 2002 to 2008, working mostly by hand, eight acres were cleared. In the two years since getting the DNR grants, that number rose to 80 acres. Last year, more than 8 million pounds of woody debris was removed from the site.

The results are aesthetically very pleasing, said Tara Kelly, Belwin's director of ecological restoration, and offer a breathtaking view of the lake that was once totally obscured. But the beauty is far beyond skin-deep.

Bur oaks that were once twisted and contorted by the restrictive undergrowth can now unfurl their graceful canopies. Young trees that struggled to reach for sunlight now flourish without the unhealthy competition.

And wildlife that is indigenous to oak savannas, like red-headed woodpeckers and wild turkeys, is already returning.