Event Title

Impacts of Dust Deposition on Lake Water Quality

Presenter Information

Janice Brahney

Location

ECC 216 - Auditorium

Streaming Media

Start Date

3-28-2017 10:20 AM

End Date

3-28-2017 10:40 AM

Description

Abstract:

Human activities have significantly altered the chemistry of the atmosphere changing the global mobility of key macronutrients. The deposition of nitrogen and phosphorus is of particular importance because these nutrients are often the most limiting in terrestrial and freshwater ecosystems. Because alpine lakes receive a large fraction of their nutrients from atmospheric deposition, variations in deposition rate and composition has the potential to impart significant changes in aquatic biogeochemistry. Using proxy evidence we examined the recent changes in dust deposition across the western US and evaluated the influence of dust- nutrient deposition on alpine lake ecosystems. We found large increases in dust deposition over broad regions of the western US. Increased dust emissions were tied to significant increases in precipitation alkalinity and to elevated nutrients in downwind lake ecosystems. Spatially we found that the global, regional, and local patterns of nutrient emissions and deposition were reflected in the water chemistry of alpine lakes. Lakes in affected areas have altered species communities, and higher levels of nutrients and heavy metal concentrations.

Comments

Janice Brahney - Utah State University - Department of Watershed Sciences

Bio: Janice received her doctorate from the University of Colorado, Boulder from the Department of Geological Sciences. Her doctorate examined the potential for dust to transport nutrients and base-cations to freshwater ecosystems. During her MS she spent time at both Simon Fraser University and the University of Waterloo where she examined climate change impacts on watershed hydrology and lake level fluctuations. Janice also holds a BS in Environmental Science with a minor in Geology from Simon Fraser University. Her undergraduate research examine top-down and bottom-up effects of salmon in costal lakes. Prior to arriving at USU, Janice was a post-doctoral scientist at the University of British Columbia, Okanagan, where she led projects on the water quality and quantity issues in the Canadian Columbia Basin.

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Mar 28th, 10:20 AM Mar 28th, 10:40 AM

Impacts of Dust Deposition on Lake Water Quality

ECC 216 - Auditorium

Abstract:

Human activities have significantly altered the chemistry of the atmosphere changing the global mobility of key macronutrients. The deposition of nitrogen and phosphorus is of particular importance because these nutrients are often the most limiting in terrestrial and freshwater ecosystems. Because alpine lakes receive a large fraction of their nutrients from atmospheric deposition, variations in deposition rate and composition has the potential to impart significant changes in aquatic biogeochemistry. Using proxy evidence we examined the recent changes in dust deposition across the western US and evaluated the influence of dust- nutrient deposition on alpine lake ecosystems. We found large increases in dust deposition over broad regions of the western US. Increased dust emissions were tied to significant increases in precipitation alkalinity and to elevated nutrients in downwind lake ecosystems. Spatially we found that the global, regional, and local patterns of nutrient emissions and deposition were reflected in the water chemistry of alpine lakes. Lakes in affected areas have altered species communities, and higher levels of nutrients and heavy metal concentrations.