Ecosystem regime shifts, stream metabolism, biogeochemical synchrony, and confluence behaviour in river networks by


23 septembre 2022


Room Ocean ( De serres)

How do river networks transform and transport energy and elements ? This is the fundamental question that underlies the work I will present, which is a collection from the past three years of collaborative research at the University of Tours and INRAe, in Lyon. I will first present a fascinating case study on riverine ecosystem recovery from anthropogenic degradation. In this work, we investigated a sudden shift from phytoplankton to macrophyte dominance in the Loire River using three decades of measurements of key state variables (i.e., turbidity, nutrient concentrations, biomass) to understand subsequent effects on ecosystem metabolism and solute uptake and transport. I will then shift towards headwater processes, focusing on the scaling behavior of dissolved oxygen and carbon dioxide fluxes through the lens of ecosystem metabolism. Third, I will present more recent work on the drivers of sub-daily synchrony in dissolved oxygen patterns in headwater networks, and how these patterns can be used for scaling sub-daily metabolism estimates to network and regional scales. Finally, I will conclude with some tidbits from ongoing projects and potential ideas for collaboration.


Jake is an environmental scientist with over 10 years of experience studying the ecology, hydrology, and biogeochemistry rivers, lakes, and wetlands across the US and France. His primary research interests are ecosystem dynamics and their services to humanity, how water, nutrients, and biota are connected across ecosystems, and natural resource management and sustainability. He grew up in Florida, USA, where he developed his fond attachment to hydrosystems and the ecosystems they support. He attended the University of Florida for a BE in Environmental Engineering and an MS in Ecohydrology after which he worked in environmental consulting in Salt Lake City, Utah for several years. He graduated with his PhD in Ecohydrology from Virginia Tech and promptly started postdoctoral work in Lyon, France, where he still resides and works.

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