ZIMMERMAN, Minn. (AP) — Hybridized cattails homogenize waterfowl habitat. Invading shrubs overtake once-open oak savannas. Non-native grasses choke out nutrient-rich plants.
Enter the Herefords.
Big appetites and sharp hooves of the 250-head herd that started grazing segments of 1,300 fenced-off acres within Sherburne National Wildlife Refuge in mid-May are making fast work of what would otherwise require considerable manpower and money — not to mention fire, fuel, chemicals and mowers, the St. Cloud Times reported (http://on.sctimes.com/18Q1fsE).
Grazing is new to the refuge but not to Steve Karel. The refuge manager who joined Sherburne in August, Karel ran similar U.S. Fish & Wildlife Service grazing programs in Kansas and Nebraska. He describes it as one more tool in the management arsenal.
It's especially important since sequestration cut into the 30,700-acre refuge's ability to fund controlled burns, which require a lot of manpower and can run $3,000 to $5,000 per fire.
This arrangement costs taxpayers nothing.
"They gain weight on cows and we're getting habitat management done," Karel said.
The project required 6 miles of fencing, at a cost of $10,000 a mile. A Legacy Amendment grant paid for 4 miles; revenue from the grazier offset staff costs to fence 2 miles.
The grazier is responsible for the cattle and the electric fencing within the perimeter.
The grazier pays about $11 per animal unit per month after deductions. A cow-calf pair is 1.2 animal units. Graziers receive deductions for efforts such as fencing, hauling water and rotating the cattle frequently. That revenue helps pay for infrastructure such as the fencing and contributes to revenue sharing.
Jason McDonald, the Kimball-based purebred beef producer who raises about 250 cow-calf pairs in Minnesota and another 150 in Montana, said the option is less expensive than buying land — and land is getting harder to come by in Minnesota.
"It's worked really well for us and for the cattle," said McDonald, whose initial questions about predators, gate locks and water supply were satisfied.
On a recent tour, Karel and wildlife biologist Tony Hewitt showed early effects of grazing on the site chosen in part because it contains elements of three habitats targeted for preservation — wetlands, oak savanna and upland prairie.
"Cattle really do a great job of managing the ground. They keep the brush down, they keep the weeds down, they keep the ground maintained," McDonald said. "I thought it was a neat opportunity to work with them to try to help manage their property."
Despite a delay brought on by a lingering winter followed by a wet spring that found cattle belly-deep in water — and therefore confined to the edges of cattail-choked pools — progress was evident two months in to a grazing season that will run through August.
Ideally, the cattle would have gotten farther into the cattails during the two weeks they were confined to the plot in late May. Karel would like the wetland to resemble a closely trimmed golf course.
By mid-July, cattails on the periphery were a foot or two shorter than those in the center. The animals cut into the duff layer, which can extend 12 inches deep and keeps other plants from taking hold. Forced to draw upon reserves, the cattails will be weaker when the next round of grazing starts on the regrowth.
"They slice open vegetation. The hoof action is probably just as important as the actual grazing," Karel said.
The goal is to open up 50 percent of the water.
Cattails do provide muskrat habitat. The plants also take up agricultural nutrients and prevent soil erosion. But Hewitt said these are a hybrid of the native broadleaf cattail and the narrowleaf cattail native to Southern states. The more dense hybrid shades out other beneficial plants such as arrowleaf, bull rush and smartweed.
"That diversity is key for habitat," Hewitt said.
Deeper into the refuge, one scene unfolds like a storyboard illustration.
Burned and grazed, to the left lies a slice of oak savanna on its way to restoration. Free of competing shrubs, prairie grasses grow under oaks' shade as far back as you can see.
Burned but ungrazed, straight ahead lie the skeletons of leafless shrubs standing among the trees. It's possible to see into, but not pass under the trees without some serious maneuvering.
Untouched by cattle and fire, to the right rises a seemingly impenetrable wall of green. Leafy shrubs, including the ubiquitous American hazel, make a dense understory.
In presettlement days, oak savanna habitat was managed by wildfires and the bison, elk and deer that followed in fire's wake. On this particular day, a pair of sandhill cranes blended in to a recently burned, rust-colored 40-acre plot just down the road from the refuge office as they foraged for insects.
The U.S. Fish & Wildlife Service refers to a 1985 study that estimated the globally imperiled oak savanna covered only .02 percent of its historic range in the Midwest.
The refuge contains 1,100 acres of oak savanna. The long-term goal would expand it to 13,000 acres.
Remnants in the best shape today were grazed before the land became a refuge in 1965.
"Our biggest issue biologically is dealing with the woody components — mostly American hazel and red oaks," Hewitt said. "If we can have cattle, they can knock back that woody vegetation."
Karel turned down a bumpy road leading into the refuge's best example of oak savanna. Wildflowers bloomed amid native grasses shaded in spots by bur oaks. Bushy, young bur oaks stood about 5 feet tall.
This is the restoration goal.
Because the refuge lies within the transition zone between prairie and hardwood forest, the battle to curb shrubs never ends.
In the upland prairie areas, where Karel is happy to see plants such as big bluestem making a comeback, cattle crush some of the shrubby plants they do not eat.
The cattle will help to control cool-season grasses such as bromegrass and Kentucky bluegrass. Grazing will allow warm-season grasses such as big and little bluestem, Indian grass, sideoats grama and switchgrass to take hold.
Hoof action also helps to control invasive species such as reed canary grass that spread by rhizomes. Reed canary grass rings most wetlands and ponds in the refuge.
"Really, it's not a battle of what we see above ground. It's a battle of what's below ground," Hewitt said.
Even with a management plan accelerated by grazing, Karel said the work he and his staff accomplish will be just one part of a bigger picture.
"We're here to put a piece or two in the puzzle. It's way beyond me being here," he said. "These habitat improvements, these are all things that are going to take time. But if we don't do something, we're going to lose it."
Bison are out.
Goats are a possibility.
When Sherburne National Wildlife Refuge looks to the future of grazing that might one day expand beyond cattle and cover more acres, staff has more to consider than would the average landowner.
The refuge's fencing requirements are more strict.
While a neighboring landowner's property provides an excellent example of how efficiently bison have cleared out the brushy understory, bison would require more extensive fencing.
Goats, on the other hand, eat just about everything and are a bit easier to contain.
The four-strand barbed-wire fence is a bit lower than standard to allow deer to clear the top wire. The bottom wire is smooth, which allows animals to wiggle underneath unharmed.
The refuge also must consider public perception and interaction.
Steve Karel, project leader at the refuge, is keenly aware that if cattle manage to get loose and wander onto a road, the refuge — not the owner — will get the blame.
The initial grazing plots are within the wildlife sanctuary, which is closed to the public March through August, reducing the chance that someone might leave a gate open.
Because the idea was new here, staff visited neighboring property owners to explain plans. (The process also required a public comment period.)
"We're not here to try to make money. We're not here for the agricultural purpose. We're here for the habitat," Karel said.
That means refuge staff, not the grazier, determines when the cattle should move from one plot to the next.
Under a traditional grazing arrangement, the cattle would be allowed to eat the grass down to the ground. Here, they might trim it to a certain length.
Information from: St. Cloud Times, http://www.sctimes.com