Fighting a pervasive invader: Crested wheatgrass


Editor's note: These stories were produced for High Country News by students in the University of Montana's online news class. They will be running over a period of two weeks in the Range blog. See a list of all the stories here.

By Rachel Seidensticker

Plastic netting lines the winding gravel road at the MPG Ranch in Florence, Mont., sheltering newly planted pines, junipers and chokecherry bushes. It’s just one of the many restoration projects taking place at this old homestead at the northern end of the Sapphire Mountains. The ranch, settled in 1881 by the Schroeder Brothers Cattle Co., is now a research station where scientists work to repair the effects of many years of grazing. One of their primary targets: crested wheatgrass.

Ecologist Dan Mummey serves as the field colonel in the fight against this relentless invader. The MPG ranch has become an 8,600-acre ecological restoration effort, largely focused on crested wheatgrass. Its 200-acre sister research ranch, MPG North, lies north of Missoula in the Swan Valley. Neither property now operates as a working ranch; instead, both serve as on-site laboratories for restoring former cattle ranges and logging areas.

Crested wheatgrass (Agropyron cristatum) is a Russian native that was originally introduced as a good, cheap livestock feed. It thrives in harsh conditions, including drought, and initially, some saw it as an ideal remedy for overgrazed rangeland. But in many places, it has taken over entirely. According to the U.S. Forest Service, over 26 million acres in North America have been planted in crested wheatgrass, almost half of it in the U.S. West. Wide bands of the grass cover rangeland across half the states in the country, where the plant forms a wall-to-wall monoculture, a Western version of an Iowa cornfield. Although livestock producers still find it useful for cattle, it crowds out native plants, growing in tight bunches that don’t leave room for anything else. It also makes for poor winter forage for wildlife.

MPG’s 19-member ranch staff includes 14 researchers and scientists, assisted by volunteers from local public schools, the University of Montana and partnerships with organizations like Raptor View Research Institute. In 2010, Mummey and his assistant, Lauren Stoffel, started working closely with the MPG team to “get a good, competitive native community back in place,” he explained. Tackling crested wheatgrass was one of their first projects.

Crested wheatgrass is a sturdy bunch grass that grows to about 3 feet tall and has a deep root system and a multiple-year seed bank. It grows two crops a year -- one in the spring and another in the fall -- and farmers and ranchers started planting it enthusiastically in the 1950s. Though it’s invasive, the grass has its advantages: It not only chokes out native grasses, it also keeps out other nuisance, nonnative weeds, such as cheatgrass – one of the West’s most-hated plants. Still, many land managers who are trying to restore native habitats want to rid themselves of wheatgrass, too. Unfortunately, there aren’t a lot of studies of this hardy, overbearing exotic. MPG’s attempts to understand and control it are some of the most aggressive now in existence.

A total of 40 acres are currently being researched as test areas for introducing other species to eradicate wheatgrass; an additional 50 will be added later this year. The tested acres are in a variety of climate zones and vegetation, general operations manager Philip Ramsey explains. On a lot of them, the MPG team has planted the non-native but beneficial plant sainfoin, experimenting with planting it after the wheatgrass has been killed with herbicide, and also planting it in healthy wheatgrass plots to see how it fares as a competitor.

Ramsey is excited about sainfoin because it’s one of the few plants able to prosper in a monoculture of crested wheatgrass. Sainfoin, a legume cousin of alfalfa, is resistant to the herbicide treatments that kill off crested wheatgrass. Bees are drawn to its pink flowers, and it attracts  grazers such as elk and deer, as well as birds. And even though it's not a native, it's not invasive and doesn’t crowd out other species of plants. Once established, it allows other native plants –– including Rocky Mountain bee plant, fringed sage, sunflowers and yarrow –– to grow with it.

Mummey and his colleagues hope sainfoin can restore areas in the ranch’s lower fields that have lost most their bird populations since wheatgrass took over. Researchers have counted only one to two bird species on those plots; Ramsey says the goal is to restore the land so that five to 10 bird species thrive on it. The more plant species there are, the more birds will use the areas for seed collection and nesting. The research team is tracking the population fluctuations of birds and other wildlife on 500 plots.

But it’s clear one plant can’t do the job alone. The other primary weapon is a chemical one: the glyphosate herbicide known as Roundup.

Next fall, Jeff Clarke, the ranch’s field crew manager and only full-time resident, will drive through a field in a four-wheeler with a long white pipe on the back lined with a rope. This “wick weeder” is a new method for MPG to apply Roundup on specific plants without disturbing other species, says Mummey. It’s also a new way to treat wheatgrass in shorter grass stands. Clarke will slowly pour Roundup into the long pipe, which filters the herbicide onto a rope adjusted to different levels, so that it touches only the tall-growing wheatgrass. The goal is to kill the plant during its fall growth cycle while everything else lies dormant.

Clarke, Mummey and the ranch team will use the wick weeder on other tall invasive weeds as well. But they also use glyphosate to kill off cheatgrass -- the nasty stuff whose seeds get caught in your socks and feel like splinters when you walk across a field. They’ll spray a pre-emergent herbicide mixture, or one that is applied before the plants sprout, of Roundup and another herbicide, Imazapic, on the cheatgrass-infested locations very late in the fall when it won’t affect other native perennials.

Mummey, Ramsey and the MPG team realize that this labor-intensive eradication method is only one of several steps toward the goal of ultimately restoring the land. The new Roundup applicator will be tested on smaller plots before attempts are made on a grander scale.

Even though it’s only in its first year of testing, the new approach is looking good. The sainfoin that was planted a year ago survived and thrived this growing season. However, the wheatgrass, with its five-year seed bank, won’t give up easily, and researchers are still steadying the long-lasting effects of their work on wildlife. As with all science, successfully proving a theory takes a long time – and a whole lot of work.

Essays in the Range blog are not written by High Country News. The authors are solely responsible for the content.

Image of MPG Ranch courtesy Rachel Seidensticker