Credit: NPS / Chavis In the late 1800s, homesteaders settled in the shade of the Tetons. These settlers transformed the landscape—they cleared the native sagebrush-steppe vegetation replacing it with oats, barley, hay, and other crops. They dug miles of irrigation ditches to support their agriculture. As hay survived the short growing season better than other crops, these settlers shifted from farming to ranching. In what now makes up the southeast corner of the park, within the area called Antelope Flats, lies a swath of these remnant fields. Hay continued to thrive long after the settlers sold and moved away. About 4,500 acres of nonnative grasses–primarily smooth brome (Bromus inermis)–remain. Since 2009, the park vegetation staff has worked on restoring Antelope Flats. This project has required a great deal of experimentation and innovation to successfully restore native plants. Research collaborations aid in guiding this time-consuming effort. 
Credit: NPS / Kramer 
Credit: Unknown The native sagebrush-steppe community, dominated by sagebrush species (Artemisia sp.), was identified as critical transitional habitat for elk, bison, pronghorn, and moose in the 2007 Bison and Elk Management Plan. This recognition spurred the park’s vegetation staff to prioritize sagebrush restoration efforts to improve wildlife habitat. In 2009, the park vegetation biologists started the multi-step process that would incrementally re-establish the native plant community. While the primary plan is to improve forage opportunities for ungulates, a return to native species will also improve the habitat for small mammals, pollinators, and birds, especially the declining greater sage-grouse population. By extension, revitalizing the Antelope Flats region is expected to enrich the area’s wildlife viewing opportunities for visitors. Sagebrush steppe supports a diverse plant community, made up of shrubs, forbs and grasses. Species of sagebrush help foster this community: the shrub catches snowfall, retaining moisture for the habitat through the spring; its branches provide shelter for seedlings to establish. A healthy sagebrush landscape is spotted with color from the many wildflowers it can host. The diverse plant species vary in structure and flowering time, adding value to the robust ecology. 
Credit: NPS / Alex Humans have had a relationship with the sagebrush steppe habitat for 11,000 years at least. People survived off its plants and wildlife and built cultural practices around its broader ecology. Many Indigenous cultures followed the region’s ungulates on their migration pathways—often through sagebrush habitat—to the Jackson Hole valley in summers and to milder climates for winters. Native Americans use sagebrush for medicinal and domestic purposes. Other plants that grow within the sagebrush habitat provided important Native food sources that would be gathered, prepared for travel, and taken from the valley each summer. There are 24 Tribes associated with Grand Teton National Park whose connection and reliance with sagebrush steppe endures to this day. Restoration is a multi-step process. To break the project into manageable pieces, park biologists divided the former agricultural lands into 20 units for treatment. Since native plants cannot establish where nonnatives are already thriving, the first step is to create site availability. Depending on the unit, prescribed burning has been used in conjunction with herbicide treatments to clear out the smooth brome monoculture. Prescribed burns kill some plant species and reduce thatch so that future herbicide applications are more effective. Careful selection of the burn period and monitoring of ambient environmental factors–for instance, wind conditions–throughout the burning ensures that the fire remains safely under control. The vegetation crew is considering using prescribed burns in older restoration units, currently dominated by grasses, to create room for shrubs and forbs. 
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Herbicide applications are the most common method used to clear the unit of nonnative vegetation. Smooth brome is most vulnerable to herbicide during the “boot stage” of reproduction, when the inflorescence (a seed-bearing flower cluster) is still encased in the stem. At this point, the plant has depleted most of energy held in the roots and rhizomes. A treatment with the herbicide glyphosate, boom-sprayed from a tractor or UTV, results in a 95 to 100 percent elimination. Other herbicides may be used for different nonnative plant species, but glyphosate has proven to be the most successful for smooth brome. After ensuring the removal was successful, the restoration team will begin planting a seed mix of native vegetation. Fall seeding has proven to be more effective than spring seeding in sagebrush restoration. The vegetation crew typically plants in October, just before the snow arrives. The seeds remain dormant throughout the winter and germinate as soon as the snow melts in spring. The native seed mix is planted by seed drill at a density that is competitive but not wasteful, nor exclusive to outside native seeds (around 25 to 35 pure-live-seeds per square foot). To increase restoration success in a site park vegetation crews also add container plants–or plugs–grown from local seed in the park nursery. Growing out native plants is a delicate and labor-intensive process that must begin at least one year in advance. Shrubs and forbs, which are slower to establish than native grasses, can be more likely to survive from this method. Ideally, plugs are added to a unit in the same season, or within a year of the seed mix. Container planting and soil transfers can also introduce bacteria and fungi that benefit native species over nonnative ones. 
Credit: NPS Native seeds are collected within the region to keep the genetic profile locally adapted and better fit to outcompete exotic weeds. Even plants that technically fall under the same species can vary genetically based on where they came from. Most of this seed is collected by hand from plants in the wild. Some is sent to be propagated in seed increase farms. This works especially well for native grasses, which can be harvested with ordinary agricultural technology. Shrubs and most forbs don’t perform as well in seed increase farms. Some species, like sagebrush, can only have their seeds collected by hand. The vegetation team monitors success throughout the entire restoration process, and well after, to guide the project’s future. Monitoring methods are both qualitative and quantitative. Point photographs, taken over time from the same vantage point, visually capture the effect of management actions, and the changing conditions of a site. Compiling a species list gives a simple but useful headcount of what all is in a plot at a given time. Once the native vegetation is seeded, changes in plant canopy cover and richness must be documented. The restoration team measures its success partially in the eradication of smooth brome from a unit. Eradication often requires subsequent treatments, applied over multiple seasons during hot and dry conditions. However, biologists have observed smooth brome resprouting, or reestablishing from the seed bank over time. The team applies spot treatments of herbicide when smooth brome, or any other concerning nonnative plants, pops up. The vegetation crew expects smooth brome, and other nonnative plants, will continue to maintain some degree of prevalence in the long term. The goal is to tip the scales in favor of the native vegetation, so that the sagebrush community prevails over what is currently a smooth brome dominated area. Even if smooth brome persists, they believe the native community, once established, can outcompete the nonnative species. Park biologists collaborate with the University of Wyoming researchers, evaluating the efficacy of restoration efforts thus far and experimenting with future methods. In 2020, biologists analyzed long-term monitoring data from thirteen of the park’s restored units. They quantified the recovery of species and trait composition (the collective attributes and characteristics of plants that effect the health of the broader ecosystem), using intact, healthy sagebrush steppe communities as a reference condition for comparison. Their goal was to determine if recovery was predictable or if the long-term conditions of sites varied based off environmental influences. While preliminary, the results suggest a degree of gradual convergence amongst sites toward reference conditions. Restored units look more like the natural sagebrush steppe community with time. However, no units have fully reached reference conditions. Site-specific influences, and differences in establishment year, seem to have sustained impacts on species in the community. For instance, sagebrush will establish well in a site with coarse soil, but grasses will dominate in a site with finer soil. 
Credit: NPS / Bonney Replicating a historical composition of species and community traits is difficult. Currently, native grasses are establishing well. But restoration plots have had low success in the establishment and diversity of shrubs and forbs. In 2020, researchers began a new study investigating seed mix and soil tilling as drivers of species diversity. They hypothesize that a forb-dominated seed mix, planted in tilled soil, would establish an optimal diversity of shrubs, forbs, and grasses. Tilling breaks up the earth, giving the seed more contact with soil, a moister environment for germination, and a preferable substrate for roots to establish in. Two seed mixes were tested: one had a low ratio of grasses to forbs and shrubs; the other had a high ratio. The experimental plots were tilled and seeded in 2022. Once available, the results may be used to adapt restoration strategies. In the United States, sagebrush occupies less than 55 percent of its historic range. The stability of sagebrush communities varies based on geography and climate. The Greater Yellowstone Ecosystem is in a better position than most; the region’s high precipitation and cold temperatures grants its sagebrush community more resilience against invasion and resistance to disturbance. The vegetation crew at Grand Teton is in a position to succeed with restoration efforts. But a warming climate could raise the sensitivity of the park’s native vegetation. Maintaining vigilance with restoration efforts and working to establish a higher diversity of native species will help preserve the sagebrush community as a regional and global resource. ReferencesBeeman, Anne., Jones, Laura. " Rooted in restoration: Collaborative sagebrush management practices and strategies." 2024 Harlow Summer Seminar Series, 27 June. 2024, UW-NPS Research Station, Moran, WY. Lecture.Wessel, S. A., Jones, L., Kramer, E., Stratton, C., Shoemaker, L., Laughlin, D. (2020) Predictability and stability of sagebrush-steppe restoration in a changing climate. UW-National Park Service Research Station Annual Report, 43, 63-73.
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Last updated: August 14, 2024