As I mention in the story, the parkland is a battleground between tallgrass prairie and aspen trees. The aspens seek to advance across open spaces in the parkland and convert them to forest. Prior to European settlement, wild fires regularly swept through the parkland to retard aspen encroachment and reinvigorate the tallgrass prairie. Grazing by bison and elk also served this purpose—but they, like wild fires, have been largely removed from the landscape.
Donovan Pietruszewski, the local wildlife manager in charge of managing the Caribou and Skull Lake wildlife management areas, waxes poetic when he talks about the historic role of fire in the parkland: "Just imagine what the Red River basin looked like prior to the plow. Miles and miles of big bluestem, Indian grass, cattails...a dry lightning storm would have likely set these ablaze, burning thousands of acres at a shot. These fires would have carried in from the tallgrass prairie of the Red River basin, into the tallgrass aspen parkland, thus maintaining their integrity."
Now, Pietruszewski says widespread agricultural development in the Red River basin has extinguished wild fires from starting there. He also says a wetter climate over the past decade is resulting in fewer dry-lightning storms that can spark a fire inside the parkland. Most of the fires in the parkland these days, he says, are the ones set by him and his partners at The Nature Conservancy.
Historically, fires renewed the parkland landscape every three to five years, Pietruszewski estimates. In a good year, with the personnel and equipment he's got, he says he's able to burn about 10,000 acres of the 96,000 acres of WMAs he manages. He burned almost 11,000 acres in 2005. But in previous years he was only able to burn 3,000 to 4,000 acres annually, due to the recent rainier climate in the parkland.
"We are way behind on burning, due to the wet conditions Mother Nature has thrown at us the past 10 to 12 years," he says.
Fortunately he receives a lot of burning help from the local office of The Nature Conservancy. TNC burns and assists in burning about 15,000 acres on the tallgrass aspen parkland every year, including land on the Conservancy's Wallace C. Dayton Conservation and Wildlife Area, as well as acreage in state WMAs and private lands. The local TNC office also conducts cross-border burns that run from Minnesota into Manitoba.
Yet, today's prescribed burns can't keep up the pace set by nature, says Pietruszewski: "I manage about 90,000 acres of burnable land in my work area, almost all of it in the tallgrass aspen parkland. If we try to replicate what nature used to burn prior to European settlement, we would need to do about 18,000 to 30,000 acres per year. It would take at least 50 percent to 75 percent more personnel and equipment than we currently operate to get this done, and it would have to be an exceptionally good burn season." [i.e. Not too much rain.]
In addition to prescribed burns, Pietruszewski also uses mechanical treatments—such as high-powered axing machines—to cut back aspen stands. And he credits the Rocky Mountain Elk Foundation, the Minnesota Sharp-Tailed Grouse Society, and the Minnesota Deer Hunters Association with direct contributions and lobbying for heritage enhancement grants from the state to help fund his fight against aspen encroachment.
But even with all this support, Pietruszewski still says he needs more help to retain and restore the tallgrass aspen parkland landscape.
"Bottom line, we need to burn as much as possible to maintain the integrity of the largest intact tallgrass aspen parkland habitat in the United States," he says.