Location: Range Sheep Production Efficiency Research
2022 Annual Report
Objectives
Objective 1. Determine ecological value of using sheep grazing to manipulate intermountain rangeland plant communities towards goals for biodiversity conservation via enhanced habitat quality.
Approach
U.S. sheep ranchers and farmers generate about one-half of the total lamb consumed in the United States; the remainder comes from New Zealand and Australia. Enhanced international competitiveness represents a great opportunity for U.S. sheep producers, many of which reside in rural communities scattered across the native rangelands of the U.S. Intermountain West. Much of these rangelands are subject to extreme climate and terrain variability and, thus, are not suitable for crop production. In this setting, rangeland-based livestock enterprises must be flexible and adaptive if they are to efficiently sustain quality food production, rural livelihoods, and ecosystem biodiversity, especially in areas of limited and variable precipitation. Accordingly, management solutions that improve rangeland resilience and robustness would have a positive effect on the health of rural communities and societies. At the same time, many stakeholder groups see Intermountain West rangelands as “wilderness habitat” for wildlife such as sage grouse, bears, wolves, and wild sheep. This leads to tension between rural communities, producers, conservationists, and environmentalists about how and for what purpose rangelands are managed. Balanced, science-based research is needed to provide sheep farmers and ranchers with solutions to improve the efficiency and competitiveness of U.S. sheep production, while informing land managers about the synergies and tradeoffs of these strategies on biodiversity conservation and profitability management objectives.
In ARS National Program (NP) projects NP 215 (current project) and 101 (associated project), scientists will address these challenges through three key opportunities for innovation: 1) enhanced sustainability and rangeland health through science-based rangeland management practices (NP 215); 2) enhanced management decision-making based on knowledge of both the benefits and tradeoffs of different management practices on multiple rangeland outcomes, including biodiversity conservation and production (NP 215); and 3) enhanced profitability and international competitiveness through greater production efficiency (NP 101). Scientists will experimentally evaluate the effects of management actions, environmental events, and(or) climatic factors on ecosystem services. Interpretation and application of research results will contribute to solutions for carbon sequestration, native rangeland ecosystem function, sustainable U.S. livestock agriculture, national food security, and rural prosperity. Within the research resource scope, these investigations include mountain big sagebrush and subalpine-tall forb ecosystems, which are habitat for sage grouse, bighorn sheep, and grizzly bear. Livestock agriculture includes domestic sheep grazing, genetics, and production.
Progress Report
This is a new National Program 215 project that started October 1, 2021 as a result of a fiscal year 2022 program increase.
In support of Objective 1, significant progress was made on determining the sheep production and ecological value of using sheep grazing to improve sage grouse-nesting habitat in recently-burned mountain big sagebrush steppe (rangeland). Long-term monitoring and permanent exclosure sites (continuous grazing rest) were sampled for biomass by species, basal and canopy cover, and rodent activity. Historic and recent climatic data, including snowpack, was collated. Permanent exclosures (continuous grazing rest) were established on U.S. Forest Service lands. Sites were selected having a long-term grazing history, the same four vegetation-type communities and similar climatic patterns as the nearby summer range on ARS property. Data were collected from the U.S. Geological Survey to estimate grizzly bear-use trends of the area.
Accomplishments
1. Timing of post-fire grazing management. Intermountain West ranchers depend on grazing public lands. After fire, land management agencies often restrict grazing access for two or more years, intending to facilitate vegetation recovery. However, outcomes of post-fire grazing deferment on vegetation recovery remains unknown. Grazing access restriction can have negative economic consequences for livestock producers. ARS researchers at Dubois, Idaho, Miles City, Montana, and Woodward, Oklahoma, conducted a replicated experiment to evaluate the effects of post-fire grazing deferment and season of fire on mountain big sage communities near Dubois. Based on the findings, grazing deferment for two years induced little change in rangeland plant communities compared with sheep grazing the subsequent fall season after fire. Furthermore, both spring and fall burns had increased perennial grass cover at four years after fire compared with unburned areas. At the study site, grazing deferment and season of burn have important economic but relatively moderate ecological implications.
Review Publications
Wilmer, H., Meadow, A.M., Bentley Brymer, A., Russo Carroll, S., Ferguson, D.B., Garba, I., Greene, C., Owen, G., Peck, D.E. 2021. Expanded ethical principles for research partnership and transdisciplinary natural resource management science. Environmental Management. 68:453-467. https://doi.org/10.1007/s00267-021-01508-4.
Spiegal, S.A., Webb, N., Boughton, E., Boughton, R., Bentley-Brymer, A., Clark, P., Holifield Collins, C.D., Hoover, D.L., Kaplan, N.E., McCord, S.E., Meredith, G., Porensky, L.M., Toledo, D.N., Wilmer, H.N., Wulfhorst, J.D., Bestelmeyer, B.T. 2022. Measuring the social and ecological performance of agricultural innovations on rangelands: Progress and plans for an indicator framework in the LTAR network. Rangelands. 44:334-344. https://doi.org/10.1016/j.rala.2021.12.005.
Wilmer, H.N., Augustine, D.J., Derner, J.D., Milchunas, D. 2020. Assessing the rate and reversibility of large herbivore effects on community composition in a semi-arid grassland ecosystem. Journal of Vegetation Science. 32(1). Article e12934. https://doi.org/10.1111/jvs.12934.
Schulz, T.T., Wilmer, H.N., Yocum, H., Winford, E., Peck, D.E., Monlezun, A.C., Schmalz, H., Klemm, T., Epstein, K., Jansen, V., Kelley, W., Bruegger, R., Fick, S., Grazing Wolf, J., Grace, J., Mann, R., Derner, J.D. 2021. Campfire conversations at the 2020 annual meeting: Insights and lessons learned from “cuss-and-discuss” rather than “chalk-and-talk”. Rangelands. 43(4):166-172. https://doi.org/10.1016/j.rala.2021.04.003.
Augustine, D.J., Derner, J.D., Fernandez-Gimenez, M., Porensky, L.M., Wilmer, H.N., Briske, D., the CRAM Stakeholder Group. 2020. Adaptive, multipaddock rotational grazing management: A ranch-scale assessment of effects on vegetation and livestock performance in semiarid rangeland. Rangeland Ecology and Management. 73(6):796-810. https://doi.org/10.1016/j.rama.2020.07.005.
