Let me begin by saying how much I love trees. My boyhood home was in the rolling hills of Missouri where the ravines and stream banks were full of oaks, stately cottonwoods, maples and shagbark hickory. Much of my art focuses on trees. Lone trees. Native oak savannas. Leaves of spring and of autumn. So here I am entranced by the works of crews at the Big Stone National Wildlife Refuge in denuding the overgrown granite outcrops of, yes, trees.
This was the surprise offered in my first loop through the Refuge this spring once the snow had melted and high waters receded. And there they were, magnificent and bare, shouldering the prairie sky as if they were once again young. Ah, those magnificent outcrops! Bared by the Glacial River Warren some 10,000 years ago, which washed away the prairie soils with such force that bedrock was exposed from here at the headwaters all the way down what is now the Minnesota River past Morton. From roads along the river you won’t see the bedrock, but you will canoeing the river or hiking along the tree-lined bluffs.
But not here, for the trees and shrubs are gone. Sawn and piled, awaiting the burn. And the outcrops? Those roughened mounds of stone, igneous and metamorphic, of granite and gneiss? Here at the Refuge they’re back. Back in their youthfulness, their bared shoulders naked to the sky, back as they were meant to be.
Laid bare, too, thanks to the chain saw, is a unique ecology, an ecosystem that dates back through eons of time; one threatened to extinction by the overgrowth. This is a select biome nestled within the craggy outcrops including, particularly here, the rare ball cactus, which are truly unique to the Big Stone and Lac qui Parle County outcrops. These small cacti are found nowhere else in Minnesota, according to Fred Harris, research scientist with the Minnesota Biological Survey.
If one is fortunate enough to follow Harris around on hikes into the outcrops along the Minnesota River, he will point out any number of rare lichens and plants, some so small and humble you must be down on hands and knees to study them. Some will send shoots skyward for a few inches, stalks barely wider than a human hair. This should be a close look, for you won’t likely see them again since they’re tied to such a limited and unique ecosystem. Flora like a wolf’s spikenosh or a short pointed umbrella sedge. Try the mouse-ear chickweed. There are a handful of others, including prickly pear, which is a giant by comparison to its cousin and the non-succulents. It’s interesting to hear people on one of Harris’ outcrop walk-abouts ask, “Cactus in Minnesota?” Yes. Native cacti!
Refuge manager, Scott Simmons, said such plants are definitely threatened by the “many types of invasive trees and shrubs that aren’t a natural part of the prairie and outcrops. In native prairie times, wildfires and grazing bison limited the extent of woody vegetation. Such methodology is in the distant past. While we can use controlled burns, which we have done in sections of the Refuge, we felt it was time to do the tree removal as a part of our active management plan.”
A drive through the Refuge will reveal piles upon piles of the downed woody species being readied for a burn next winter. “We ask that people be patient with us as we work to restore the granite outcrops and hopefully maintain their unique plant life. It won’t happen overnight,” he said.
There were other issues with the overgrowth. The weed trees provided cover and perching sites for predators that threatened both grassland birds and the waterfowl harboring in the nearby shallow waters … ducks and geese are actually the backbone of the reasons for creating the Refuge.
Simmons noted that numerous tactics have been attempted including fenced-in goats to help knock back the buckthorn and other brushy plants, and for years even crops were grown on selected portions. Controlled burns have been targeted for other portions of the Refuge on both the prairie that eases toward Marsh Lake and on the bluff-like hillsides created by that incredible rush of waters with the breaking of the ice dam on Lake Agassiz 10,000 to 12,000 years ago — back when the bedrock, or outcrops, that date billions of years old, were first exposed.
One doesn’t have to go far to see the negative effect of overgrowth on similar outcrops, for just below the headwaters at the town of Ortonville, and before the Refuge, the standing outcrops are thwarted significantly by the invasive trees. Muted. Hidden. Overgrown. This is a sacred land of Native Americans, and Simmons now wishes he had been in his position when the land came up for sale several years ago.
The opportunity to “refurbish” the outcrops within the Refuge was seized by decision makers like Simmons, who along with his colleagues worked tediously to unveil these beautiful craggy features of this unique headwaters natural history. A friend who grew up nearby remembers playing on these very same outcrops some 60 years ago, and was stunned when he saw the difference. “It’s like my own childhood was back,” he said.
Come winter Simmons and crew will burn the dried piles of timber, and in time the shiny stumps will weather and gray, eventually rotting completely away. So, yes, just a little patience and time will provide future generations a glimpse of an era long forgotten, this paean to geological history.