FARGO - Dwindling grassland remnants in the Great Plains continued their decline last year with the loss of 2.5 million acres consumed by expanding crop production.
The reduction, which included a loss of 266,127 grassland acres in North Dakota, was tallied by a "Plowprint" report recently released by the World Wildlife Fund.
The loss of grassland acres has been an ongoing concern to conservationists. The longstanding trend accelerated a few years ago when high crop prices enticed farmers to expand their cropland. The trend continued in 2016, although at a slower rate, even with the more recent drop in farm commodity prices, the World Wildlife Fund report said.
The previous year, 2015, 3.7 million grassland acres disappeared due to crop conversion. Since 2009, about 8 percent of grasslands in the Great Plains have been lost to crop expansion, according to the World Wildlife Fund report.
"Converting these grasslands impairs their ability to offer services, such as providing habitat for wildlife, storing carbon, stabilizing the soil, connecting migration corridors and filtering and retaining water for communities in this region and downstream," the World Wildlife Fund report said. "It is their dual role in providing for human communities and wildlife that makes the conservation of these grasslands so critical."
Grasslands are an "absolutely underappreciated ecosystem," said Martha Kaufman, the World Wildlife Fund's managing director for the northern Great Plains, based in Bozeman, Mont. "Globally one of the most threatened and least-protected ecosystems."
Although high crop prices have encouraged farmers to plow under grassland, declining support to set aside marginal land as conservation reserve acres also can play a role, according to conservationists.
"The economics are what drive a lot of the behavior we see," Kaufman said. "Another driver is policies that kind of set up the playing field out there. Policies can definitely influence which way things go."
'Area of high concern'
The northern Great Plains lost more than 700,000 grassland acres last year, an annual loss rate of 0.55 percent, down from the 0.75-percent loss rate the year before.
A handful of crops accounted for most of the grassland acres that were converted to cropland: 43 percent were planted in wheat, 11 percent in corn, 7 percent in soybeans and 7 percent lentils, according to the World Wildlife Fund report, which is drawn from figures compiled by the U.S. Department of Agriculture.
In North Dakota, about 25 percent of the grassland habitat that predated settlement still exists, according to an estimate by Ducks Unlimited, a conservation group that works to preserve wetlands and grasslands. In South Dakota, about 35 percent of grasslands remain.
The vast Prairie Pothole Region, which includes much of North Dakota, critical wetland and grassland habitat for waterfowl, is especially threatened, Kaufman said.
"The Prairie Pothole Region is definitely experiencing the fastest losses," she said. "It's also where there tend to be better soils. It's an area of high concern."
In the Prairie Pothole Region of North Dakota, South Dakota, Montana, Minnesota and Iowa, about 10 million acres of grassland have been preserved, according to Ducks Unlimited.
This year's "Plowprint" report, the second in what the World Wildlife Fund intends to be an annual report, highlights the importance of grasslands in supporting waterfowl and in helping filter and store water.
Estimates by the World Wildlife Fund project that conserving grasslands that are expected to be lost could save 1.7 trillion gallons of water, or about 4 percent of the total flow in the Missouri River Basin. That's enough water for 11.6 million four-person households annually.
At the same time, that amount of grassland conservation would also save 46 million tons of sediment each year, or about 9 percent of the total sediment in the Missouri River Basin, as well as saving significant amounts of phosphorous and nitrogen, fertilizers that run off farm fields and pollute waterways.
Nutrient pollution has been linked to dead zones in the Gulf of Mexico, which are killing marine life.
Despite the continued net loss of grasslands, in some areas cropland is going back into perennial, grassland cover: 336,037 acres throughout the Great Plains, including 264,229 acres in the northern Great Plains.
But North Dakota has seen 59,238 fewer acres in perennial cover plants, according to Kaufman.
Despite the incentive to plow under grassland to convert it to cropland, conservation programs remain popular with farmers and ranchers, said Johann Walker, director of conservation for Ducks Unlimited in the Dakotas and Montana.
"We can deliver as much conservation as we have funding to provide," he said. Because of limited funding, however, not all interested landowners can enroll. Now that work is beginning on the 2018 farm bill, conservationists hope more money can be made available, Walker said.