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ARS Home » Plains Area » Miles City, Montana » Range and Livestock Research » Research » Research Project #424156

Research Project: Adaptive Rangeland Management of Livestock Grazing, Disturbance, and Climatic Variation

Location: Range and Livestock Research

2014 Annual Report

1a. Objectives (from AD-416):
Objective 1: Develop management strategies to improve rangeland cattle production and ecological stability in the northern Great Plains through effective use of rangeland forage resources, precision supplementation, and livestock with greater adaptability to climatic, physiological, and nutritional stress. Sub-objective 1.1 Determine effects of dormant rangeland forage utilization on heifer development, plant productivity, and species composition. Sub-objective 1.2 Develop nutritional management for post-weaning heifer development to complement annual and weather-driven fluctuations in forage availability and quality. Sub-objective 1.3 Estimate effects of vegetation, climate, and environmental variables on cattle growth. Sub-objective 1.4 Develop mineral supplement and water amendment strategies to ameliorate weather-induced changes in naturally occurring rangeland stock water quality. Sub-objective 1.5 Develop a molecular barcode system for northern mixed-grass prairie plant species that will enable future description of plants consumed by livestock on rangelands. Objective 2: Develop management strategies integrating grazing, fire, and chemical practices to restore rangelands degraded by weeds and prevent weed invasions in the northern Great Plains. Sub-objective 2.1 Develop fire and herbicide treatment combinations to reduce annual brome abundance in rangelands. Sub-objective 2.2 Develop effective practices to rehabilitate rangeland riverine sites that have been mechanically and chemically treated to eradicate Russian olive. Sub-objective 2.3 Identify and develop effective reclamation strategies for converting coal mining lands back to livestock grazing lands. Sub-objective 2.4 Determine physiological traits allowing perennial seedlings to use dormancy to survive unfavorable environmental conditions. Objective 3: Develop adaptive strategies for managing the interacting effects of livestock grazing, fire, and climatic variation on northern Great Plains rangelands to increase the stability of livestock production while maintaining ecosystem health. Sub-objective 3.1 Quantify grazing season and intensity effects on plant community composition and productivity. Sub-objective 3.2 Quantify interacting effects of climate with defoliation timing and intensity on rangeland stability. Sub-objective 3.3 Determine rangeland community response to autumn defoliation intensity. Sub-objective 3.4 Determine post-fire weather effects on plant community response to summer fire. Sub-objective 3.5 Determine the effect of mycorrhizal fungi and different levels of simulated grazing on plant community composition and measures of soil health. Sub-objective 3.6 Determine plant and soil community response to fire return interval and seasonality.

1b. Approach (from AD-416):
Sustainability of rangeland production hinges on the stability of plant communities because changes in species composition, forage production, and forage quality fundamentally affect the animal community. The primary forces of change in rangelands are weather, grazing, alien plants, and fire. This project is designed to improve ecological sustainability and rangeland production by addressing opportunities for increased efficiency of livestock nutrient conversion, mechanisms affecting restoration success, and interacting effects of disturbances with weather and climate. We propose improved efficiency of nutrient conversion from dormant rangeland forages is among the most viable options for increasing animal production and minimizing effects on plant communities. We will address this proposition through a series of experiments evaluating plant and animal responses to dormant-season utilization and supplementation strategies. Rangeland restoration methods will be evaluated for direct weed control and mechanisms controlling successful establishment of desirable species. Water manipulations will be included in multiple experiments to determine weather and long-term climate effects because precipitation is the primary controlling factor for plant productivity and community composition. Experiments will be integrated across objectives to determine interacting effects of precipitation, grazing, weeds, and fire on soil and plant communities (production, species composition, diversity, propagation, survival) and cattle (weight gain, reproductive performance, diet quality, diet selection). Understanding the mechanisms that control rangeland stability and animal responses to alterations in plant communities will assist land managers and livestock producers in improving rangeland integrity and efficiency of livestock production. Results will also provide scientists greater understanding of the complex interacting forces on rangelands.

3. Progress Report:
Phenotypic and biomass data continue to be collected to assess the impact of fall (dormant season) grazing on annual forage production and how strategic supplementation impacts heifer development. Fenceline weaned heifers were developed on rangeland as well as pregnant first calf heifers using supplements that include metabolic stimulators that target deficiencies observed in cattle grazing dormant range forage. Completed survey of Genbank for relevant sequence data, experiment designed, plant samples for 32 plant species collected. Fungicide and mowing treatments applied, constructed ~400 mycorrhizal ingrowth bags to be deployed in fall, and harvested a mycorrhizal dependency experiment for 69 plant species. Season and frequency of fire treatments were applied, vegetation measurements were taken and additional samples were collected to screen for foliar fungal endophytes. Grazing intensity x season experiments were treated for the second year as were mechanical defoliation treatments. Herbicide was applied to fire x herbicide experiment for controlling annual brome. First year response data were collected for fall defoliation experiment.

4. Accomplishments
1. Semiarid Rangeland is resilient to summer fire and post-fire grazing utilization. Understanding plant response to grazing following summer fire is required to reduce ecological and financial risks associated with wildfire because most wildfires occur during summer and fire effects during this season are least understood. ARS researchers at Miles City, MT determined that summer fire had no first-year effect on productivity for any biomass component and that grazing after fire had no effect on total aboveground productivity the year after grazing compared to nonburned, non-grazed sites. Fire and grazing increased grass productivity 16% and reduced forbs (51%), annual grasses (49%), and litter (46%). Results indicate grazing with up to 50% biomass removal the first growing season after summer fire was not detrimental to productivity of semiarid rangeland plant communities and livestock exclusion the year after summer fire did not increase productivity or shift species composition compared to grazed sites. The consistent responses among dry, wet, and near-average years suggest plant response is species-specific rather than climatically controlled. Results are changing post-fire grazing management decisions, particularly for federally managed lands that required one to three years of livestock removal following fire.

2. Summer and fall fire reduce purple threeawn and increase forage quality. Purple threeawn is a native perennial grass with very poor forage quality that can invade disturbed sites and dominate them for decades. ARS researchers at Miles City, MT discovered that a single summer or fall fire can reduce threeawn biomass and cover 58 to 90% whereas co-existing native species respond positively or neutrally to fire, shifting the community to a more desirable composition. Heat dosage and duration of heat in the crown of the plant during fire were identified as the factors most controlling threeawn mortality. Fire increased crude protein and digestibility of threeawn to the extent that it went from being unsuitable as a forage for cattle growth to being comparable to other rangeland forage species in quality. This research was the first to observe fire-induced reductions in silica content of a plant, with non-burned plants being 7% silica and fire reducing the value to 4%. The magnitude and duration of effects indicate fire is a practicable management solution to threeawn invasion and dominance.

Review Publications
Rinella, M.J., Vavra, M., Naylor, B.J., Boyd, J.M. 2011. Estimating influence of stocking regimes on livestock grazing distributions. Ecological Modeling 222:619-625.

Petersen, M.K., Mueller, C.J., Mulliniks, J.T., Roberts, A.J., Delcurto, T., Waterman, R.C. 2014. Potential limitations of NRC in predicting energetic requirements of beef females within western U.S. grazing systems. Journal of Animal Science. 92:2800-2808.

Dufek, N.A., Vermeire, L.T., Waterman, R.C., Ganguli, A.C. 2014. Effects of fire and nitrogen addition on forage quality of Aristida purpurea. Rangeland Ecology and Management. 67(3):298-306.

Strong, D.J., Ganguli, A.C., Vermeire, L.T. 2013. Fire effects on basal area, tiller production, and mortality of the C4 Bunchgrass, Purple Threeawn. Fire Ecology. 9(3):89-99.

Rinella, M.J., Bellows, S.E., Roth, A.D. 2014. Aminopyrald and Picloram reduce seed production of the invasive annual grasses Medusahead and Ventenata. Rangeland Ecology and Management. 67:406-411.

Waterman, R.C., Caton, J.S., Loest, C.A., Petersen, M.K., Roberts, A.J. 2014. An assessment of the 1996 Beef NRC: Metabolizable protein supply and demand and effectiveness of model performance prediction of beef females within extensive grazing systems. Journal of Animal Science. 92:2785-2799.

Beckstead, J., Meyer, S.E., Reinhart, K.O., Bergen, K.M., Holden, S.R., Boekweg, H.F. 2014. Factors affecting host range in a generalist seed pathogen of semi-arid shrublands. Plant Ecology. 215:427-440.

Vermeire, L.T., Crowder, J.L., Wester, D.B. 2014. Semiarid rangeland is resilient to summer fire and postfire grazing utilization. Rangeland Ecology and Management. 67:52-60.

Strong, D.J., Vermeire, L.T., Ganguli, A.C. 2013. Fire and nitrogen effects on Purple Threeawn abundance in northern mixed-grass prairie old fields. Rangeland Ecology and Management. 66:553-560.

Reeves, J.L., Derner, J.D., Sanderson, M.A., Hendrickson, J.R., Kronberg, S.L., Petersen, M.K., Vermeire, L.T. 2013. Seasonal weather influences on yearling beef steer production in C3-dominated Northern Great Plains rangeland. Agriculture, Ecosystems and Environment. 183:110-117.

Svejcar, A.J., Boyd, C.S., Davies, K.W., Madsen, M.D., Bates, J.D., Sheley, R.L., Marlow, C., Bohnert, D., Borman, M., Mata-Gonzalez, R., Buckhouse, J., Stringham, T., Perryman, B., Swanson, S., Tate, K., George, M., Ruyle, G., Roundy, B., Call, C., Jensen, K.B., Launchbaugh, K., Gearhart, A., Vermeire, L.T., Tanaka, J., Derner, J.D., Frasier, G.W., Havstad, K.M. 2014. Western land managers will need all available tools for adapting to climate change, including grazing: A critique of Beschta et al. Environmental Management. 53:1035-1038. DOI: 10.1007/s00267-013-0218-2.

Lugo, M.A., Reinhart, K.O., Menoyo, E., Crespo, E., Urcelay, C. 2014. Plant functional traits and phylogenetic relatedness explain variation in associations with root fungal endophytes in an extreme arid environment. Mycorrhiza. 25:85-95.

Toledo, D.N., Sanderson, M.A., Johnson, H.A., Reeves, J.L., Derner, J.D., Vermeire, L.T., Hendrickson, J.R. 2014. Evaluating plant biodiversity measurements and exotic species detection in National Resources Inventory Sampling protocols using examples from the Northern Great Plains of the USA. Ecological Indicators. 46:149-155.