Return of the tallgrass prairieby Dan Gunderson, Minnesota Public Radio
The largest prairie and wetland restoration project in the nation is taking shape in northwestern Minnesota. When it's completed, the Glacial Ridge project will be a 35,000 acre national wildlife refuge.
Polk County, Minn. — A sunny July morning is a good time for a walk on the beach, even though it's been about 10,000 years since waves crashed on this rocky shoreline. The meandering swell in an otherwise flat landscape is one of several beach ridges left behind as Glacial Lake Agassiz receded.
Nature Conservancy Restoration Ecologist Jason Ekstein looks out over the old glacial lake bed where fields of wheat, soybeans and sugar beets now stretch to the horizon. The rich farmland is far too valuable to restore to native prairie. Much of the remaining prairie can be found on these beach ridges where the soil is sandy, rocky and not very good for farming.
Two centuries ago ago more than 18 million acres of prairie covered the western half of Minnesota. Most of the prairie is gone now, plowed under for farmland.
Eight years ago The Nature Conservancy bought 24,000 acres here in Polk County, about 12 miles east of Crookston, Minn.
Most of the land was plowed in the 1970s when the farm economy was booming. A few thousand acres of native prairie remained on land that had been grazed but not plowed. The prairie has started to regenerate.
"There's a little prairie smoke seed left behind you there, next to purple prairie clover," Ekstein said as he surveyed the top of a ridge. "I guess if you walked across this little ridge top here, you could easily come up with 50 species."
This is dry prairie, but just a couple hundred feet away the land dips into a wetland.
"And that's typical of what these beach ridges used to look like," Ekstein said, "changing between three or four habitats within basically a baseball throw."
Even though it's less than half completed, the prairie restoration is already showing some success.
One very noticeable example is the prairie chicken population, which is larger than it's been for decades.
This year, people came from as far away as Texas to watch the prairie chickens' annual spring mating dance.
Nate Emery picks his way through waist-high grass with what looks like a small television antenna held in front of him. A steady beeping directs him to a prairie chicken that wears a radio collar.
The hen and chicks fly as Emery gets near. Emery is studying how prairie chickens use this large prairie area.
"This year they seem to be as numerous, if not more, than last year," said Emergy. "And last year was more than I've ever seen before that, in four years of undergraduate work and a couple years of graduate work."
In fact, prairie chickens are doing so well here that several dozen are being captured to help rebuild the prairie chicken population in Wisconsin.
The prairie is also attracting birds that aren't often seen in Minnesota. For example, a pair of endangered burrowing owls raised two owlets here last year. It's the only pair known to nest in Minnesota.
Glacial Ridge National Wildlife Refuge Manager Dave Bennett expects more rare species to stop here.
As the Nature Conservancy restores prairies and wetlands, the land will be given to the federal government.
Bennett says this will be the largest area of native prairie in Minnesota. The refuge and adjacent state lands will create a prairie area covering about 55 square miles.
Bennett says it will be about as close as animals or people can come to experiencing what the prairie was like before European settlement.
"You can walk for 10 miles and go through prairie habitat. It's just going to be very unique," Bennett said.
With only the sound of the ubiquitous prairie wind and birds singing nearby, Bennett pauses to survey the horizon.
"Even for a few seconds here you don't hear any sounds of the rest of the world. There's no airplane going over, no train going by, nobody going down the highway. You can imagine what the first pioneers saw when they came here and thought man, the world must go on forever, just wide open spaces," Bennett said.
Restoring native prairie is much more complicated than just planting wildflowers. It takes several years for the native species to overcome invasive plants introduced by farming.
Bennett says the original prairie was shaped by wildfires and the hooves of wandering bison. He says this large chunk of prairie will need the same kind of management.
"When I look across those ridges can I shut my eyes and one day imagine buffalo returning and we see an ecosystem back at its basic life support system. Who knows, maybe that will happen," Bennett says.
There is a plan to reintroduce bison and perhaps elk to this prairie landscape at some time in the future.
While the Nature Conservancy is restoring thousands of acres of prairie, they are also filling in miles of ditches and restoring dozens of wetlands.
Some of the ditches here were dug in the early 1900s. Others were built in the 1970s.
Ekstein stands next to a ditch slated to be filled in later this year. He says when the this land was farmed, the ditch ran full for weeks after a heavy rain.
"Since we've restored the prairie upstream of it now, you can see we're just down to a small trickle. We're going to turn the release of water off the property close to zero percent. We'll basically be holding it all back on the property," Ekstein says.
That means most of the rain or snow that falls here will stay here, filling wetlands, reducing downstream flooding and helping recharge the groundwater.
The Nature Conservancy will turn another chunk of restored prairie over to the federal government is fall, but there are many years of work ahead before this prairie refuge is completed.
- Morning Edition, 07/31/2008, 7:23 a.m.