Sometime soon — maybe this year, maybe next — biologist Jeffrey Glassberg expects to say goodbye to the Poweshiek skipperling. The endangered, orange-and-brown butterfly is one of several species in the Upper Midwest’s prairies on the slippery slope toward extinction. In the past decade, it appears to have winked out in the Dakotas, Iowa and Minnesota, leaving only a scattered few individuals in Michigan, Wisconsin and Manitoba.

As founder and president of the North American Butterfly Association, Glassberg finds their twilight wrenching. “I can’t tell you how painful this whole thing is,” he says.

Prairie butterflies owe their troubles largely to the conversion of native grasslands — among the most diverse ecosystems on the planet — to row-crop agriculture. Only about 4 percent of America’s prairie remains, according to the National Park Service; one report found that the Great Plains lost more grassland in 2014 than Brazil’s Amazon lost forest. Grassland conversion also has fueled disturbing declines in other pollinating insects — which provide some US$9 billion a year in agricultural benefits in the U.S. — and grassland birds, whose populations have plummeted more steeply and consistently in recent decades than any other group of North American birds.

One tool with potential to help stem that loss is the U.S. Farm Bill, a mammoth piece of federal legislation updated every five years or so. Along with food assistance, crop insurance and other provisions, the bill includes the largest pot of federal funding for habitat conservation on private lands. Through it, the U.S. Department of Agriculture helps farmers create wildlife corridors, restore wetlands, plant swaths of grass along streams to filter out pollutants and more.

The footprint of those projects is vast; around 50 million acres (20 million hectares) are enrolled in at least one Farm Bill conservation program. But many advocates say USDA isn’t tapping the bill’s full potential to provide the kind of habitat prairie butterflies and other native wildlife need. While some of the bill’s conservation components encourage farmers to plant native species, they also allow the use of introduced plants, which experts say don’t provide the same caliber of wildlife habitat and other benefits.

Now, that could change. Just in time for the latest round of deliberations, 50 wildlife groups, seed companies and other organizations are urging Congress to support a policy leveraging the grassland-restoring power of the national purse by adding a native-plant standard to the new Farm Bill taking shape on Capitol Hill.

“What we’re trying to do is to work with landowners, not require them to use native vegetation, but demonstrate to them the advantages both for their economic purposes and for wildlife.” – Tom Franklin The policy proposed by the Natives First Coalition would be voluntary and wouldn’t add regulations for farmers, but it would give funding preference to conservation projects that use native plants.

“What we’re trying to do is to work with landowners, not require them to use native vegetation, but demonstrate to them the advantages both for their economic purposes and for wildlife,” says Tom Franklin, agriculture liaison for the National Bobwhite Conservation Initiative, which leads the coalition.

Offsetting Benefits

Advocates say native plants provide better wildlife food and habitat for native species than introduced species do, produce high-quality livestock forage that is more drought tolerant, are better at preventing soil erosion, and trap more atmospheric carbon underground.

“Native vegetation provides at least as good of benefits for conservation and wildlife as introduced vegetation,” Franklin says. “So why not use it?”

Before there was a general understanding of the benefits of native vegetation and the risks of invasive plants — introduced species that outcompete other species, spread quickly and alter ecosystems — USDA had a hand in introducing foreign plants that proved aggressive. Long ago, the agency promoted kudzu for erosion control. Now it works to control invasive species and does not provide assistance for planting them. It also actively promotes the use of native species through some programs.

“The problem is, at the same time, they’re also funding other practices that continue to allow or encourage the planting of introduced species,” Franklin says. “We’re kind of offsetting a lot of the benefits by continuing these older practices.”

Not all introduced plants become invasive, and many of them have benefits for wildlife, water quality and soil health, USDA spokesman Michael Illenberg notes. The agency helps farmers plant noninvasive introduced species in some situations, if doing so fits their goals and budgets, he says.

Time to Adjust

It’s likely impossible to fully quantify the conservation land area covered in introduced vegetation through the Farm Bill, but experts say it is substantial. Several official practices in the Conservation Reserve Program (CRP) — which pays farmers to plant grasses or other cover instead of crops for 10 to 15 years — allow or encourage non-native grasses such as smooth bromegrass (which, USDA warns, can become invasive), timothy-grass and orchardgrass. The most recent CRP data show, for instance, that while 5.6 million acres (2.3 million hectares) were enrolled in Conservation Practice 2, which requires native grasses, another 3.3 million acres (1.3 million hectares) used Conservation Practice 1, which calls for introduced species.

Proponents acknowledge that, if adopted, the natives-first standard could raise the cost of conservation plantings at first.Franklin says other CRP practices commonly use introduced plants, as do other Farm Bill programs; his group estimates that non-natives were planted on 1.25 million acres (510,000 hectares) via the bill’s Environmental Quality Incentives Program in 2014.

Proponents acknowledge that, if adopted, the natives-first standard could raise the cost of conservation plantings at first, since many seed companies produce non-native mixes and would need time to adjust.

“That’s likely to be the main concern,” says Alex Echols, executive vice president of Ecosystem Services Exchange, who helped write the Farm Bill’s first conservation provisions in 1985. “But long term, the market is really good at sorting that out. Folks don’t like to be told what to do, but if the market supports it, they’re pretty quick to adapt.”

Cautiously Optimistic

With many provisions of the most recent Farm Bill set to expire at the end of September, congressional agriculture committees have been busy gathering public input, and the House panel could draft a bill this spring — though Franklin says it looks increasingly likely that a final deal won’t be reached until 2019. So far, he is “cautiously optimistic” about the native plant standard’s chances. “It’s not a done deal in either committee, but I think they’ve been favorably persuaded of the desirability of this idea,” he says.

If lawmakers greenlight the natives-first proposal, it likely won’t be enough to save the Poweshiek skipperling, Glassberg says, but it’s a step in the right direction for other butterflies and birds. His organization signed a coalition letter to key legislators urging their support.

“Native plants are critical,” he says. “Without them, butterflies can’t survive.”