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ARS Home » Pacific West Area » Boise, Idaho » Northwest Watershed Research Center » Research » Research Project #436155

Research Project: Assessment and Mitigation of Disturbed Sagebrush-Steppe Ecosystems

Location: Northwest Watershed Research Center

2019 Annual Report

1) As part of the Long-Term Agroecosystems Research (LTAR) network, and in concert with similar long-term, 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 (LTARN, 2015), 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. 1A) Improve the understanding of Great Basin ecosystem function and processes by collecting, analyzing and curating multi-scale data in support of LTAR and national database development efforts. 1B) Develop and evaluate remote-sensing tools and approaches for quantifying fine-scale vegetation and wildland fuel dynamics. 1C) Contribute and utilize weather and climate tool applications through the LTAR Climate Group for national and regional LTAR agricultural and natural resource modeling programs in grazing management, ecosystem monitoring, remote sensing, soil productivity, hydrology and erosion. 1D) Create a framework of dominant socioeconomic metrics for assessing long-term sustainability of livestock production and ecosystem services relevant to rural communities dependent upon Great Basin rangelands. 2) Evaluate the interacting effects of livestock grazing, fire, and invasive plants on rangeland ecosystems through development, testing, and application of new databases, assessment tools, and management strategies. 2A) Determine if strategically targeted cattle grazing is effective for reducing fine fuels, moderating wildfire behavior, providing better initial attack alternatives for wildland fire fighters, and protecting critical resources from wildfire damage. 2B) Assess the efficacy of prescriptive cattle grazing for rehabilitating and/or restoring degraded sagebrush-steppe rangelands currently dominated by invasive annual grasses. 2C) Evaluate impacts of the interaction of fire and annual grass invasion on hillslope ecohydrologic processes. 3) Develop weather, climate and eco-hydrologic tools for agricultural and natural resource management applications. 3A) Evaluate, develop and implement soil, plant and atmospheric modeling tools for evaluating and optimizing planting date effects on seedling establishment success of rangeland restoration plant materials. 3B) Evaluate, develop and implement landscape-scale applications for weather centric rangeland restoration planning and management. 3C) Enhance the applicability of the Rangeland Hydrology and Erosion Model (RHEM) for assessing ecohydrologic impacts of annual grass invasion and altered fire regimes.

Goal 1A: Improve infrastructure, data acquisition protocols, and database management at the Great Basin LTAR. Install phenology cameras and extend vegetation monitoring of replicated sites in three Great Basin (GB) ecosystems. Hypothesis 1B: Unmanned aircraft systems (UAS) will be effective for quantifying vegetation dynamics and fire severity. We will test efficacy of high-resolution imagery, Structure-from-Motion (SfM), and other UAS-derived products for estimating biomass, cover, fuel continuity, and fire severity in the three GB ecosystems. Goal 1C: Develop methodology for utilizing gridded weather data for agro-ecosystem modeling and risk-assessment applications. The weather/climate toolbox will be expanded to provide forecasting data for the entire U.S. to support the LTAR network and broad research efforts. Goal 1D: Develop a socio-economic framework for assessing barriers to adoption of livestock grazing systems in cheatgrass rangelands. Scoping interviews, surveys, and participatory workshops will be used to assess stakeholder and community perceptions of rangeland issues and changes in those perceptions over time. Hypothesis 2A: Targeted grazing can create fuel breaks which moderate wildfire behavior without impacting ecosystem health. We will apply intensive grazing to cheatgrass rangeland, monitor herbaceous fuel height/load reduction to targeted level, and assess ecosystem response to treatment using augmented indicators and protocols developed for the BLM Assessment, Inventory, and Monitoring (AIM) program. Hypothesis 2B: Prescriptive grazing will promote recovery of desirable plant species within degraded rangelands. We will apply replicates of a combination of spring and dormant season grazing to impact cheatgrass cohorts and monitor ecosystem response using AIM indicators and protocols. Hypothesis 2C: Cheatgrass invasion and associated altered fire regimes will increase runoff and erosion. Runoff and erosion will be assessed in unburned and burned cheatgrass compared to unburned sagebrush-steppe (control) using rainfall and overland-flow field simulators. Hypothesis 3A: Hydrothermal germination response models and weather datasets can characterize seed germination, post-germination mortality, and seedling emergence rates. The SHAW model using historical weather data from gridMet will be used to parameterize hydrothermal germination models to evaluate species sensitivity to planting date, over-wintering conditions, and topo-edaphic conditions. Goal 3B: Develop tools for incorporating weather, climate and microclimatic variability into restoration planning and management. We will enhance existing web-application to provide daily weather parameters and parameterize the SHAW model with SSURGO soils data to thus facilitate modeling of germination success and seedling survival under various climatic and environmental scenarios. Goal 3C: Expand the capabilities of RHEM for conducting hydrologic risk assessment on disturbed rangelands. Develop RHEM equations for cheatgrass systems, test the utility of the enhanced RHEM, and establish guidelines for use of RHEM in combination with soil burn severity mapping for risk assessments.

Progress Report
This report documents progress for the parent project 2052-13610-014-00D "Assessment and Mitigation of Disturbed Sagebrush-Steppe Ecosystems", which started March 2019 and continues research from project 2052-13610-013-00D "Assessment, Conservation and Management of Rangelands in Transition". Related to Objective 1, researchers at Boise, Idaho, maintained an existing phenology camera (Nancy Gulch) and installed a new camera (Reynolds Mountain) at the Reynolds Creek Experimental Watershed (RCEW) located in Murphy, Idaho. Both automated cameras successfully provided imagery to both the nation-wide Long-Term Agroecosystem Research (LTAR) and the Phenocam Networks. Data collections for the RCEW Long-Term Vegetation Research program were completed as planned. Field reconnaissance was conducted in collaboration with representatives from the National Wind Erosion Network to determine long-term wind erosion tower sites in the RCEW and in the neighboring Snake River Birds of Prey National Conservation Area (SR BoP NCA). Seventy-five wind erosion samplers were constructed and are ready to deploy along with the wind erosion tower and additional identified sample points throughout the RCEW. Research continued on collecting imagery from Unmanned Aircraft Systems (UAS) and corresponding field data from three core research areas at the RCEW (Nancy Gulch, Lower Sheep Creek, and Reynolds Mountain). The imagery and field data were submitted for inclusion in a global study evaluating UAS imagery for estimating vegetation biomass using Structure-from-Motion (SfM) analyses. These efforts include collaborations with Boise State University (2052-13610-014-10A, "Developing Remote Sensing Tools for Rangeland Vegetation Inventory and Assessment") through a graduate student thesis to compare remote sensing techniques to quantify plant cover characteristics. Researchers at Boise, Idaho, collaborated with the USDA Southwest Climate Hub (SWCH), LTAR Weather and Climate Working Group, and University of Idaho (UI) to develop a LTAR website that provides point and gridded weather time-series data for modeling applications within the LTAR network. This website has reached the beta-testing phase, and when operational, will be posted on the ARS-LTAR website, and USDA-SWCH websites in FY 2020. Collaborative efforts with the UI (2052-13610-014-12S, "Socio-economic Assessment of Great Basin Livestock Production Systems") are underway on a design for an initial stakeholder-based participatory workshop. Field visits with landowners associated with the cheatgrass prescriptive grazing were conducted involving introductory discussions about the human dimensions of utilizing such practices. A presentation was given at the UI Rangeland Center Fall Forum on project objectives and solicitation of involvement by livestock producers. A planning meeting with the Executive Board of the UI Rangeland Center was also conducted to solicit possible future project collaborations on human dimensions work. An invited plenary talk was also given at the National Meeting for the LTAR Network on human dimensions studies conducted in southwest Idaho related to landscape-scale vegetation management practices associated with the Great Basin LTAR Site. Related to Objective 2, the Multi-Regional Targeted Grazing Experiment was expanded to include a third study area (Beaty Butte, Oregon) and the required background-year data for vegetation composition and production were collected for that site. All required treatment-year data were successfully collected at the Elko, Nevada, and Boise, Idaho, study areas. Summarizations of the data were provided to the Bureau of Land Management (BLM) Washington DC Office (2052-13610-014-08I, "BLM/ARS Targeted Grazing Demonstration Monitoring Project"). Field data collections for the High-Intensity Low Frequency (HILF) Grazing Project proceeded as planned. An interim report of findings for the first three years of the project was provided to BLM Boise District, SR BoP NCA, and Four Rivers Field offices and the cattle producers who are the principal project collaborators. Researchers at Boise, Idaho, collaborated with the LTAR Livestock Tracking Working Group to evaluate the effects of soil type and topography on cattle foraging behavior in rangeland and pasture settings throughout the U.S. ARS Researchers met with researchers from Tucson, Arizona, to explore potential field sites in Utah and Idaho, and to outline the experimental design for future rainfall-simulation and overland-flow studies of cheatgrass impacts on upland runoff and erosion processes. A final study site has not yet been determined. Related to Objective 3, researchers at Boise, Idaho; Fort Collins, Colorado; Woodward, Oklahoma; and Burns, Oregon, collaborated to evaluate planting date effects on germination response of diverse perennial grass species. The identifying weather patterns associated with both successful seedling establishment and post-planting winter mortality in the Great Basin. ARS scientists at Boise, Idaho, also collaborated with the UI (2052-13610-014-09A, "Generic Weather and Climate Tools for Agricultural and Natural Resource Modeling Application"), University of Utah, Oklahoma State University, University of Nevada, and other ARS rangeland, forage, and grass research locations to develop and publish tools and protocols for using historical weather data for retrospective assessment of rangeland restoration outcomes on disturbed rangelands in the western U.S. These protocols are available on the website,, and contribute to the annual training program given by the BLM for rangeland restoration managers and practitioners. This group of collaborators also developed and published guidance for the incorporation contingency planning for weather and climate variability in long-term rangeland restoration planning in the western U.S. A synthesized dataset related to infiltration capacity and soil hydrophobicity was created based upon multiple past experiments conducted by researchers at Boise, Idaho, looking at the hydrologic impacts of fire and vegetation regrowth within shrubland ecosystems in Idaho, Nevada, Utah, Oregon and Arizona. Summarization and analysis of these data were initiated to determine if predictive relationships exist. Results from these past studies also contributed to a synthesis on the impacts of juniper encroachment on hydrologic and erosion processes across climatic gradients of the western U.S. It also contributed to a scientific paper on whether fire can control juniper and act to reverse the negative hydrologic impacts caused by juniper invasion of sagebrush shrublands.

1. Weather-centric contingency planning for rangeland restoration. Recent changes in federal rangeland-restoration planning and management policy provide opportunities to better incorporate weather and climate information into multi-year revegetation management efforts in the intermountain west. Researchers at Boise, Idaho, in collaboration with colleagues from Burns, Oregon; Woodward, Oklahoma; Moscow, Idaho; Stillwater, Oklahoma; Logan, Utah; and Reno, Nevada, developed new tools for characterizing the historical variability in seedbed microclimates for plant establishment, and new strategies for multiple-year contingency planning of rangeland restoration management. These retrospective analysis tools have been made available on a website ( and contribute to the annual training program currently given by the U.S. Bureau of Land Management for rangeland restoration planners and managers. Weather-centric, contingency-based rangeland restoration planning could significantly improve rangeland restoration outcomes over millions of acres of disturbed rangeland in the western U.S.

Review Publications
Flerchinger, G.N., Fellows, A.W., Seyfried, M.S., Clark, P.E., Lohse, K.A. 2019. Water and carbon fluxes along an elevational gradient in a sagebrush ecosystem. Ecosystems.
Renwick, K.M., Fellows, A., Flerchinger, G.N., Lohse, K.A., Clark, P.E., Smith, W.K., Emmett, K., Poulter, B. 2019. Modeling phenological controls on carbon dynamics in dryland sagebrush ecosystems. Agricultural and Forest Meteorology. 274:85-94.
Shin, S., Park, S., Pierson, F.B., Williams, C.J. 2019. Evaluation of physical erosivity factor for interrill erosion on steep vegetated hillslopes. Journal of Hydrology. 571:559-572.
Williams, C.J., Pierson, F.B., Nouwakpo, S., Kormos, P., Al-Hamdab, O.Z., Weltz, M.A. 2019. Long-term evidence for fire as an ecohydrologic threshold reversal mechanism on woodland-encroached sagebrush shrublands. Ecohydrology. 12(4):e2086.