Collaborative Research: Quantifying Feedbacks between Groundwater Decline, Wind Erosion, and Ecological Change in Desert Vegetation

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This award will fund an analysis of the interactions between groundwater, soil and vegetation properties, and desert dust generation. Wind erosion of desert soils is thought to cause irreversible change to ecosystems, and the mobilized particulate matter can seriously degrade air quality. In deserts globally, regions that produce the most dust are characterized by low elevation depressions where wind erodible material has been and continues to be deposited fluvially. Shallow groundwater is often pumped from these regions for agricultural and municipal use. Since water demands are rapidly increasingly in many desert regions, there is increasing need to understand of how groundwater management might influence dust generation. Ideally, information could be attained that would guide groundwater management with the goal of promoting soil stability. This project will utilize measurements of vegetation and soil conditions and wind velocities to model wind erosion at a range of sites that experienced successively greater groundwater fluctuation over the past 20 years. Model results will be compared to direct measurements of recent soil loss using radiogenic fallout isotopes and dust traps. Finally, measurements of soil resource availability (nutrients and soil moisture) will be used to understand feedback processes between groundwater decline, soil loss, and ecosystem changes that might promote continued soil instability. Broader Impacts: The project will have a broad impact on our understanding of the role water management has on dust and air quality in deserts. The work will form collaborations between academic institutions and regulatory groups in the proposed study region, near Bishop, California. Both the Inyo County Water Department and the Great Basin Unified Air Pollution Control District will provide necessary data to the project and gain important information on how their vegetation and air quality management activities could be tailored to gain long-term sustainability.