Location: Northwest Watershed Research Center2018 Annual Report
Management goals on rangelands are often based on a perception that the ecosystem is unbalanced or disturbed. Management plans in public and private sectors increasingly require quantification and estimation of ecological and fiscal costs and benefits of proposed land treatments. Predictions of land treatment effects, potential conservation benefits, and the relevance of alternative treatment options are very complicated in a landscape with extremely high variability in soil, vegetation, weather, management, and disturbance regime. The project objectives all address these general issues relating to the spatial and temporal variability in landscape-scale disturbance, evaluation of management treatments and their effectiveness in the context of this variability, and developing adaptive and mitigating strategies for negative impacts of invasive annual grasses, juniper expansion, and potential climate change. Each component of this program includes new and innovative basic research; enhancement, testing and validation of predictive models; and development of technology-transfer applications for use by land management agencies and other rangeland resource managers, cooperators and partners. 1) Develop management tools for hydrologic and erosion assessment of the impacts of fire, weed-invasions, and conservation practices on Great Basin sagebrush steppe rangelands to aid public and private land managers in formulating conservation strategies and selecting effective conservation practices. 2) Develop decision-support tools that will improve the success of rangeland restoration projects in the Great Basin by integrating weather, climate, microclimate and forecast data into ecological site descriptions and conservation practice models to reduce the risks of climatic uncertainties. 3) Develop adaptive grazing management strategies for shrub-steppe rangelands impacted by fire, juniper and other invasive weeds to improve livestock productivity while enhancing other ecosystems services. 4) Conduct research as part of the LTAR network, and in concert with similar longterm, land-based research infrastructure in the U.S, use the Great Basin LTAR site to improve the observational capabilities and data accessibility of the LTAR network and support research to sustain or enhance agricultural production and environmental quality in agroecosystems characteristic of the Great Basin. Research and data collection are planned and implemented based on the LTAR site application and in accordance with the responsibilities outlined in the LTAR Shared Research Strategy, a living document that serves as a roadmap for LTAR implementation. Participation in the LTAR network includes research and data management in support of the ARS GRACEnet and/or Livestock GRACEnet projects. 4A)Create "business as usual" and "aspirational" production and ecosystem service system scenarios as outlined by the LTAR common experiment. Assess the sustainability of both systems and develop new strategies to enable greater sustainability.
Rangeland resources across the Intermountain West have been severely impacted by range expansion of non-native and native weeds such as cheatgrass and juniper and altered natural wildfire regimes. Nonnative annual grass invasions into sagebrush steppe have established self-perpetuating increases in wildfire frequency and extent. At higher elevations, juniper encroachment into sagebrush steppe has occurred due to poorly-managed livestock grazing, fire suppression and climate change. Range expansion of these weeds and changes in the role of fire have negatively impacted upland and riparian ecosystem health, biodiversity, rates of runoff and erosion, livestock distribution and productivity, wildlife habitat and economic viability of rural communities. Land management agencies, nongovernmental organizations, private landowners and environmental groups across the West are seeking conservation strategies to mitigate and/or reverse negative effects of weed expansion. This project will develop management tools and guidelines to assist management of weed-disturbed rangelands under current and potential future climate conditions in the Great Basin. Specific products include: (1) management tools for assessing hydrologic/erosion risk and targeting of conservation practices; (2) weather and climate data processing tools and models for improving the success of rangeland restoration practices; and (3) guidelines for optimal management of livestock distribution and grazing behavior in intact and disturbed rangeland systems. Resultant benefits include potential savings of millions of dollars in wildfire mitigation, improved water quality by reducing sediment delivered to streams, reduced loss of forage for livestock and wildlife from cheatgrass and juniper invasion, improved species diversity and wildlife habitat, and greater livestock productivity from rangeland systems.
This report documents progress for bridging project 2052-13610-013-00D, "Assessment, Conservation and Management of Rangelands in Transition," which started in February 2018 and continues research from project 2052-13610-011-00D, which is currently undergoing NP215 Office of Scientific Quality Review. Related to Objectives 1 and 4, the Northwest Watershed Research Center (NWRC) scientists in Boise, Idaho completed data analysis and drafted a manuscript based on a large regional experiment (SageSTEP) addressing long-term (10-year post treatment) ecohydrologic impacts of western juniper control treatments. Field data samples were processed, entered and data analyzed for a field study of the impacts of fire on ecohydrologic function at varying scales in Reynolds Creek Experimental Watershed (RCEW). A journal article documenting the latest dynamic version of the Rangeland Hydrology and Erosion (RHEM) model was submitted to Water Resources Research. Related to Objectives 2 and 4, NWRC scientists cooperated with other ARS scientists of the Long-Term Agroecosystem Research (LTAR) team and the USDA Climate Hub network to expand the weather and climate toolbox previously developed for rangeland restoration applications to facilitate use by other ARS modeling programs. These programs include the following models: Soil and Water Assessment Tool (SWAT), Erosion Productivity Impact Calculator and Agricultural Policy Environmental Extender and Erosion (EPIC/APEX), Integrated Farm System Model (IFSM), Structural Equation Modeling (SEM), Simultaneous Heat and Water (SHAW), Agricultural Land Management Alternative with Numerical Assessment Criteria (ALMANAC), AgES (main public repository), Phenology Modular Modeling System (MMS), Unified Plant Growth Model (UPGM) and Kinematic Runoff and Erosion Model_Automated Geospatial Watershed Assessment (KINEROS_AGWA). NWRC is developing a new website in collaboration with other members of the LTAR Climate Working Group to make gridded weather data products specifically tailored for input requirements of LTAR-related models, and to evaluate seasonal forecast model output for management applications in the natural resource and agricultural system management. Related to Objectives 3 and 4, field vegetation data collection protocols were further clarified and enhanced to improve the quality and precision of biomass and Aboveground Net Primary Productivity (ANPP) data collected at RCEW. Remote sensing imagery was successfully acquired using a small Unmanned Aircraft System (UAS) and applied to measure vegetation and fuel heights using Structure from Motion (SfM) analysis techniques. Targeted grazing treatment application and field sampling of fuel height, fuel load, and ecosystem responses were conducted at two project sites (Boise, Idaho and Elko, Nevada) as part of the Bureau of Land Management (BLM), targeted grazing project (2052-13610-013-10I, BLM/ARS Targeted Grazing Demonstration Monitoring Project). Prescribed grazing application and field sampling of forage utilization was conducted at the Mountain Home, Idaho site as part of the collaborative prescribed grazing project with BLM (2052-13610-013-04N, NFCA between USDA-ARS, Howard Ranches, and BLM). A manuscript addressing phenological controls on carbon dynamics in dryland sagebrush ecosystems was prepared and submitted to the Agricultural and Forest Meteorology. A cross-site LTAR manuscript addressing strategies for sustainable intensification of U.S. agriculture through the LTAR network was submitted to Environmental Research Letters. A manuscript describing the use of cattle spatial behavior models for predicting the risk of wolf-cattle encounters and depredation events was prepared and submitted to Rangeland Ecology and Management.
Clark, P., Williams, C.J., Pierson, F.B. 2018. Factors affecting efficacy of prescribed fire for western juniper control. Rangeland Ecology and Management. 71(3):345-355. https://doi.org/10.1016/j.rama.2018.02.002.
Hardegree, S.P., Roundy, B., Walters, C.T., Reeves, P.A., Richards, C.M., Moffet, C., Sheley, R.L., Flerchinger, G.N. 2018. Hydrothermal germination models: assessment of the wet-thermal approximation of potential field response. Crop Science. 58(5):2042-2049. https://doi.org/10.2135/cropsci2017.11.0666.
Spiegal, S.A., Bestelmeyer, B.T., Archer, D.W., Augustine, D.J., Boughton, E., Boughton, R., Clark, P., Derner, J.D., Duncan, E.W., Cavigelli, M.A., Hapeman, C.J., Harmel, R.D., Heilman, P., Holly, M.A., Huggins, D.R., King, K.W., Kleinman, P.J., Liebig, M.A., Locke, M.A., McCarty, G.W., Millar, N., Mirsky, S.B., Moorman, T.B., Pierson, F.B., Rigby, J.R., Robertson, G., Steiner, J.L., Strickland, T.C., Swain, H., Wienhold, B.J., Wulfhorts, J., Yost, M., Walthall, C.L. 2018. Evaluating strategies for sustainable intensification of U.S. agriculture through the Long-Term Agroecosystem Research network. Environmental Research Letters. 13(3):034031. https://doi.org/10.1088/1748-9326/aaa779.