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April 26, 2019

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Karoline Qasem Coauthored a Paper on The Effect of Floods on Ecosystem Metabolism in Suburban Streams in the Journal Freshwater Science

Karoline Qasem, Ph.D. (Illinois) coauthored a paper entitled "The effect of floods on ecosystem metabolism in suburban streams" published in the journal Freshwater Science in Volume 38, Issue 2 on April 11, 2019.

Karoline was the lead author, and her coauthors were Sean Vitousek, Ben O'Connor, and Timothy Hoellein.

Karoline is a Senior Staff Professional based in Illinois who is focused on water quality modeling and data analysis.

Freshwater Science publishes articles that advance understanding and environmental stewardship of all types of inland aquatic ecosystems (lakes, rivers, streams, reservoirs, subterranean, and estuaries) and ecosystems at the interface between aquatic and terrestrial habitats (wetlands, riparian areas, and floodplains). The journal regularly features papers on a wide range of topics, including physical, chemical, and biological properties of lentic and lotic habitats; ecosystem processes; structure and dynamics of populations, communities, and ecosystems; ecology, systematics, and genetics of freshwater organisms, from bacteria to vertebrates; linkages between freshwater and other ecosystems and between freshwater ecology and other aquatic sciences; bioassessment, conservation, and restoration; environmental management; and new or novel methods for basic or applied research.


Urban and suburban streams experience rapid changes in flow during flood events, which can affect ecosystem function and stream metabolism (i.e., gross primary production [GPP], ecosystem respiration [ER], and net ecosystem production [NEP]). To assess these effects, we calculated stream metabolism from hourly measurements of dissolved oxygen (DO), temperature, and flow at seven sites around the Chicago region during summer and fall of 2009 to 2013. We examined the biophysical effect of flood events by calculating metrics that characterized GPP and ER's resistance (magnitude of change) and resilience (speed of recovery) to flooding as well as flood flashiness. Diel patterns in DO and GPP were observed during base flow conditions and flood events. Streams showed net heterotrophy at most of the sites, as GPP ranged from 0.98 – 6.61 g O2 m−2 d−1, ER ranged from −3.62 to −19.53 g O2 m−2 d−1, and NEP ranged from −16.84 to 1.06 g O2 m−2 d−1. Following floods, both GPP and ER decreased but ER exhibited a significantly higher resistance (i.e., changed less) than GPP. ER and GPP recovered to preflood levels within approximately 1 to 10 days, and there was no significant difference between ER and GPP resilience. Overall, our study indicates that large flow events sustain heterotrophic conditions more than autotrophic conditions. We concluded that flood events significantly affected stream metabolism and flood flashiness was a primary controlling factor on reducing metabolism rates.

More Information

Learn more about the article: https://www.journals.uchicago.edu/doi/pdfplus/10.1086/703459
Learn more about the journal: https://www.journals.uchicago.edu/journals/fws/about
For consultation regarding suburban streams, contact Karoline Qasem at This email address is being protected from spambots. You need JavaScript enabled to view it..
Learn more about Karoline at: https://www.linkedin.com/in/karolineqasem/