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Master
Etats Unis
2022
Urbanization and Freshwater Salinity : Impacts on Water Quality, Sediment, and Microbial Communities in Semi-Arid Streams
Titre : Urbanization and Freshwater Salinity : Impacts on Water Quality, Sediment, and Microbial Communities in Semi-Arid Streams
Auteur : Seto, Keenan.
Université de soutenance : University of Nevada, Reno
Grade : Master of Science in Natural Resources and Environmental Science 2022
Résumé
Stream ecosystems can be sensitive to watershed urbanization, but less is known about how
streams respond to urbanization in semi-arid cities. To characterize how urbanization and
altered salinity regimes affect stream chemistry and microbial activity, I conducted (1) a
mesocosm experiment to investigate how press versus pulse salinity regimes altered
biogeochemical cycles in stream sediments and (2) a field survey of streams in Reno,
Nevada. The mesocosm experiment results revealed that the press salinity regime caused
the greatest fluxes in ammonium and potassium from exposed stream sediments, while
microbial activity rates were not affected. Results from the field survey demonstrated that
the heterogenous underlying lithology of Reno imparted a stronger signal on stream
chemistry than watershed urbanization in paired sites. The results of this work characterize
the wide temporal and spatial variability in how stream chemistry and microbial activity
respond to urbanization and altered salinity regimes in a semi-arid city
Page publiée le 10 avril 2023