Location: Great Basin Rangelands Research
Project Number: 2060-13610-003-029-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Mar 15, 2020
End Date: Mar 14, 2025
Both aeolian and hydrologic processes contribute substantially to overall soil erosion and loss of ecosystem services. The primary objective of this agreement is to construct the scientific foundation for documenting what is known and what is not known about the environmental effects of wildfires, conservation practices and management actions on rangelands wind and water erosion processes. The University of Nevada at Reno is undertaking a cooperative project with the Agricultural Research Service to evaluate if the Rangeland Hydrology and Erosion Model can successfully quantify soil erosion on rangelands. A second aspect is to evaluate the impacts of adding compost to California annual grasslands to enhance the health of these plant communities under changing climates. The third component of the joint effort is to assess wind erosion on areas recently burned by wildfire and the benefits of revegetation in reducing dust fluxes from disturbed rangelands. Ecological processes are often poorly understood on annual grasslands and poorly documented for post fire sagebrush steppe plant communities in ecological site descriptions. Accurate wind and water erosion predictions on annual grasslands with the ability to estimate high risk areas for erosion will improve the conservation planning process and ultimately, the success of conservation management decisions. The project will determine if the addition of organic amendments (compost) can be added to California annual rangeland without negative effects to water quality or have negative environmental outcomes associated with the hydrologic function of the ecological site. The project will quantify dust fluxes pre and post fire disturbance on sagebrush plant communities in the Great Basin in association with conservation/revegetation practices. The ARS and University of Nevada Reno will 1) expand the RHEM model annual grasslands, 2) test impacts on soil surface erosion and hydrologic function of compost applied to rangelands, 3) provide course material for eco-hydrology training 4) inform the hydrologic sections of ecological site descriptions, and 5) establish dust flux monitoring stations to document benefits of revegetation.
The University of Nevada at Reno will assist ARS in conducting rainfall simulation experiments to quantify rainfall/runoff relationships and mobility and transport processes of compost applications on 2 annual grass dominated ecological sites in California. Based on these findings the team will use this information to improve the USDA Rangeland Hydrology and Erosion Model’s ability to predict how this specific conservation practice will improve rangeland health, water quantity and quality of western rivers. The University of Nevada Reno will assist ARS and NRCS in expanding the Rangeland Hydrology and Erosion Model (RHEM) to develop predictions of erosion on perennial pasturelands. The team will work with ARS hydrologic research stations across the U.S. to retrieve historic datasets on rainfall/runoff/soil erosion/sediment transport experiments on pastures. The team will then compare observed to predicted results of soil erosion. If beneficial and sufficient data exist them team will then develop an optimized model input parameters to enhance performance of the RHEM assessment tool and modify the RHEM User Guide to include instructions for using RHEM on pastures. The team will assist in the development of a workshop to train NRCS staff on dominant hydrologic and erosion process on rangelands. In addition, the workshop will provide direct training on the RHEM assessment tool, information on the equations implemented in RHEM, and how to access and interpret model predictions using examples from across the United States for different ecological and climatic conditions. The University of Nevada at Reno will assist ARS in establishing and monitoring 2 dust flux stations in central Nevada in post burned sagebrush steppe plant communities. Based on these findings the team will use this information to improve estimates of wind erosion in the Great Basin.