Grasslands store carbon, cycle nutrients and sustain songbirds and other wildlife—yet less than half of all grasslands remain, and we plow up millions more acres each year.
Nestled among other native wildflowers, purple blazing stars seem to glow at sunset on a Missouri prairie (above) during early spring. Vast tracts of uniform row crops, such as corn in Minnesota (below), have replaced most of North America’s biodiverse grasslands. (Photo above by Noppadol Paothong)
ON A PATCH OF SWAYING TALLGRASS PRAIRIE in Missouri, yellow and purple coneflowers peek above a sea of green, attracting monarch butterflies with their sweet nectar. Bumble bees hover around the dainty petals of wild bergamot while meadowlarks call amidst head-high big bluestem and eastern gamagrass.
Historically, grasslands—or prairies—such as this covered one-third of the United States and one-quarter of the entire planet. Their diverse plants fuel an array of pollinators and feed a wealth of other wildlife, from elk and pronghorn to prairie chickens and bobwhite quail. Some prairies are so diverse that they boast more plant species per square foot than a tropical rain forest. Below ground, those plants’ dense root systems cycle nutrients, hold water, store carbon and create some of the world’s most fertile soils.
But the world has lost half of its vital grasslands—and the other half is at risk. “Of all terrestrial ecosystems, temperate grasslands are one of the least protected and most threatened,” says Carol Davit, executive director of the Missouri Prairie Foundation, which works to protect and restore that state’s remaining grasslands.
Missouri has less than one-half of 1 percent of its original prairie left. Like much of the once-grand Great Plains—which stretches from the Mississippi River west to the Rocky Mountains—the state’s native plants have been plowed under and replaced with crops and human development. The losses began in the mid-19th century, when settlers migrating west converted the region into America’s breadbasket. But once grassland ecosystems are broken to plant crops—called “sodbusting”—it’s harder than Humpty Dumpty to piece them back together again.
“We’re still losing 1 million acres of grasslands each year in the U.S.,” says Tyler Lark, a land-change scientist at the University of Wisconsin’s Nelson Institute for Environmental Studies. “To make matters worse, the converted land was some of the highest-quality wildlife habitat in the country, even though it’s quite marginal for growing food.” According to the World Wildlife Fund’s 2020 Plowprint Report, an area the size of four football fields is converted to cropland every minute. The vast majority of this land is planted in homogeneous rows of corn, soybeans or wheat.
Because the most-fertile land already has been cultivated, what remains is subpar for farming: drier areas or places prone to flooding. These areas also tend to be life-rich “ecotones,” the zones where agricultural lands and grasslands mix. In many landscapes, this interface provides crucial refuge and migration corridors for a host of at-risk animals such as mountain plovers and black-footed ferrets.
Wildlife habitat is not all we lose when grasslands are uprooted. We also lose precious carbon stores, contributing to climate change. “We know that cutting or burning forests releases a lot of carbon, but most people don’t realize that the same thing happens when we plow up grasslands,” says Joe Fargione, science director for The Nature Conservancy’s North America region.
On prairies, four times as much biomass grows below ground as above. Grasslands are like upside-down forests, where deep, fibrous roots stockpile carbon in the soils. Worldwide, 12 percent of all terrestrial carbon stocks are stored in rangelands—landscapes where grazing animals (domestic, wild or both) roam through mostly native grasses and shrubs.
“We lose 30 percent of the soil carbon when we bust through the top 12 inches of sod,” says Fargione. In a 2018 study, he found that preventing the conversion of prairies to crops provides the biggest opportunity to reduce carbon emissions and mitigate climate change within the U.S. agricultural sector.
Lark and colleague Seth Spawn calculated that between 2008 and 2012, the amount of carbon released from cultivating crops was 38 million metric tons per year—the equivalent of adding 20 million more cars to the road or running 36 coal-fired power plants. “We’re hemorrhaging carbon from our landscapes by tilling up the soil. The first thing we need to do is stop the bleeding,” says Lark.
More than 90 percent of the nation’s remaining 360 million acres of grasslands are now privately owned, primarily by agricultural producers. In an effort to keep prairies in grass—and carbon in soils—nonprofit organizations and government agencies have developed a variety of creative tools and incentives to help landowners steward this imperiled habitat. “The No. 1 climate-smart action we can take in this ecosystem is to prevent soil disturbance,” says Julie Sibbing, the National Wildlife Federation’s associate vice president for land stewardship. To help keep more plants in the ground year-round, NWF promotes practices such as planting cover crops between commercial crop seasons and no-till farming, which does not require annual plowing.
One of the best ways to conserve remaining grasslands is to support responsible livestock grazing, says Sibbing. “Cattle can help save the birds and bees, so we need to preserve ranching and the grazing way of life, rather than encouraging people to break grass and plant corn,” she says.
Grasslands evolved with bison, pronghorn and other animals whose hooves and grazing open new areas for plants to grow. The aboveground stems of prairie grasses and flowers rebound quickly after they’ve been eaten, much as pruning backyard trees or shrubs creates healthier plants. When managed carefully, domestic animals such as cattle or sheep can have the same positive impact on grassland ecosystems.
“In the western part of the country, we like to say ‘what’s good for the herd is good for the bird,’” says Jimmy Bramblett, deputy chief for programs at the U.S. Department of Agriculture’s (USDA) Natural Resources Conservation Service (NRCS). “The Great Plains are the backbone of the U.S. beef industry and also offer critical habitat for a lot of wildlife. We aim to strike a balance that meets the needs of natural resources while also helping producers remain economically viable.”
Several NRCS programs provide financial and technical assistance to landowners who agree to improve the soils, water quality and native plants on their land. Since 2010, Working Lands for Wildlife, the agency’s premier approach for conserving such lands, has protected more than 10 million acres with 3,261 participating ranchers. Last year, NRCS released a new biome-scale framework for grassland wildlife conservation that aims to conserve an additional 9.8 million acres in the Great Plains alone by 2025.
Another USDA program that encourages producers to grow grass instead of crops is the Conservation Reserve Program (CRP) in which, in exchange for annual rental payments, farmers take cropland out of production and plant perennial grasses that grow year-round. The CRP currently protects more than 20 million acres of topsoil, preventing more than 12 million metric tons of carbon dioxide from entering the atmosphere. This year, the department upped its payments for farmers who enroll in CRP, with the goal of replanting perennials on 4 million additional acres to help mitigate climate change. Because CRP contracts last just 10 to 15 years—meaning millions of acres annually expire from the program and are again at risk for sodbusting—NRCS in its new grasslands framework proposes a novel solution: helping landowners transition restored grasslands into profitable livestock grazing lands so they don’t have to turn back to row-crop agriculture when payments run out.
In South Dakota, the Lower Brule Sioux Tribe is also turning cropland back to native prairie. So far, its Department of Wildlife, Fish and Recreation has restored 11,000 acres on its reservation, which stretches across 220,000 acres of undulating prairie and the rugged Missouri River Breaks. When land becomes available, the department leases it long-term from the Tribe so that elk, bison, ring-necked pheasants, prairie chickens and other wildlife can use it. If the land had been planted in crops, Tribe members replant a mix of native grasses and forbs (flowering perennials).
“We always try to match up the plants based on which wildlife species are most likely to use them,” says Tribe member and wildlife biologist Shaun Grassel. One tract he helped restore was within pronghorn range, for example, so the Tribe planted a mix of shortgrass and mid-grass species as well as the drought-tolerant forbs that pronghorn prefer. Another area was more of an “edge zone” bordering croplands and the Missouri River. Here, the Tribe planted taller grasses and forbs that thrive in wetter soils and are favored by white-tailed deer and pheasants. “Our goal is always to restore as much of the prairies as we can,” says Grassel.
Whether on private, public or tribal lands, growing more grass has helped birds. A recent study in the southern Great Plains led by the Bird Conservancy of the Rockies found that private lands enrolled in sustainable grazing programs or CRP boosted populations of 16 bird species, providing the greatest benefits to vulnerable species, including Cassin’s sparrows, eastern meadowlarks and grasshopper sparrows. In 2016, the study estimates that such grassland conservation programs contributed 4.5 million birds to the region.
Those are uplifting results in an era of bad news for birds. Research published in 2019 in Science concluded that North America has lost nearly 3 billion total birds during the past 50 years. Grassland birds showed the largest population loss, with 74 percent of grassland bird species declining.
Yet conservation history shows that we can bring birds back: Thanks largely to wetland restoration initiatives—many funded through the North American Wetlands Conservation Act—the continent’s number of ducks, geese and other waterfowl, once thought to be on the verge of collapse, has swelled by 34 million since 1970. Hoping for similar success with grassland species, NWF is working with partners to introduce a North American Grasslands Conservation Act. “This bill would elevate the importance of grasslands in the public eye and create new sources of funding to help ranchers restore, conserve and sustainably manage what remains of our vital prairies,” says Aviva Glaser, the Federation’s director for agriculture policy.
There’s still plenty left to save—and celebrate. “America is home to some of the largest remaining intact prairies in the world,” says Dirac Twidwell, a rangeland ecologist at the University of Nebraska. In that state’s Sandhills, for example, pronghorn and prairie chickens strut among 670 different types of native plants on wide-open grasslands that stretch for 265 miles. In Kansas, the Flint Hills’ thriving tallgrass prairie covers an area nearly twice as big as New Jersey. This ocean of swaying stems provides prime wildlife habitat and supplies income for ranchers and rural communities.
Grasslands do not have to be large to be valuable. Even a patch of prairie the size of a city block can play an important ecological role, says Davit. “These remnant prairies are teeming with life. They should never be written off.”
Twidwell agrees, emphasizing that grasslands are experiencing more biodiversity loss than any other biome. “If we work together on creative solutions,” he says, “we can conserve grasslands on a scale that matters and make sure our prairies don’t become fragmented relics of the past.”
To improve soil health and boost biodiversity on cultivated lands, two National Wildlife Federation outreach initiatives—the Grow More and Conservation Champions programs—encourage farmers to adopt conservation practices. “We teach conservation professionals how to reframe soil conservation as a solution to a specific on-farm problem,” says Jessica Espenshade, NWF’s sustainable agriculture program manager, who is hopeful about the potential for protecting what remains of the Great Plains grasslands. “Farmers and ranchers are No. 1 problem solvers,” she says. “If you put a problem in front of them and ask them to be part of the solution, they’re happy to work together as a community to make it better.” To learn more about North America’s grasslands and their conservation, check out the proceedings of NWF’s biennial America’s Grasslands Conference at nwf.org/grasslandsconference. For more information about the North American Grasslands Conservation Act, visit ActForGrasslands.org.
Brianna Randall is a science writer based in Montana.
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