Short-term and seasonal variability of oxygen fluxes at the sediment–water interface in a riverine lake
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In situ measurements of sediment-water oxygen fluxes conducted in a riverine lake during different seasons were analyzed with the aim of quantifying the combined effects of hydrodynamic forcing and seasonal changes in temperature on sediment oxygen uptake rate. Oxygen fluxes measured using the eddy correlation (EC) technique varied widely between −6.4 and −84 mmol m−2 day−1, while variations observed on hourly time scales were of comparable magnitude to seasonal variations. Oxygen fluxes were most strongly correlated to current speed in the benthic boundary layer and water depth, which both co-varied with discharge, temperature, and oxygen concentration. A direct correlation of measured fluxes with temperature and corresponding seasonal flux variations could not be observed. To explore the potential effect of temperature on oxygen fluxes, we applied a simplified analytical model, which couples the effect of hydrodynamic forcing with a temperature-dependent oxygen consumption rate within the sediment. The results suggest that the flux is a non-linear function of both variables and both can have comparable effects on the magnitude of the oxygen fluxes. The model confirms our observation that short-term variations of oxygen fluxes in response to hydrodynamic forcing can mask longer-term seasonal variations driven by temperature. The model further indicates that the magnitude and form of the temperature dependence of oxygen uptake and mineralization rates in freshwater sediments obtained from laboratory incubations can be strongly affected by flow conditions during incubations. We conclude that predictions of oxygen uptake and mineralization rates under changing climatic conditions should also take potential changes of flow conditions into account.
KeywordsHydrodynamics Oxygen flux Riverine lakes Sediment–water interface
We thank the German Federal Institute of Hydrology (BfG) for providing bathymetry data for the Havel River, the Waterways and Navigation Office (WSA) Berlin for providing boats and facilities for our measurements, A. Glud (University of Southern Denmark) for the oxygen microsensors, and C. E. Bluteau (University of Western Australia) for sharing the Matlab script for the inertial dissipation method. This study was part of the KLIWAS research program of the German Federal Ministry of Transport, Building, and Urban Development (BMVBS). EM was funded by a scholarship of the German Academic Exchange Service (DAAD). We thank and gratefully acknowledge P. Berg and two anonymous reviewers for their critical and constructive comments that helped improve the manuscript.
- Cole JJ, Prairie YT, Caraco NF, McDowell WH, Tranvik LJ, Striegl RG, Duarte CM, Kortelainen P, Downing JA, Middelburg JJ, Melack J (2007) Plumbing the global carbon cycle: integrating inland waters into the terrestrial carbon budget. Ecosystems 10(1):172–185. doi: 10.1007/s10021-006-9013-8 CrossRefGoogle Scholar
- Regnier P, Friedlingstein P, Ciais P, Mackenzie FT, Gruber N, Janssens IA, Laruelle GG, Lauerwald R, Luyssaert S, Andersson AJ, Arndt S, Arnosti C, Borges AV, Dale AW, Gallego-Sala A, Godderis Y, Goossens N, Hartmann J, Heinze C, Ilyina T, Joos F, LaRowe DE, Leifeld J, Meysman FJR, Munhoven G, Raymond PA, Spahni R, Suntharalingam P, Thullner M (2013) Anthropogenic perturbation of the carbon fluxes from land to ocean. Nat Geosci 6(8):597–607. doi: 10.1038/ngeo1830 CrossRefGoogle Scholar
- Tranvik LJ, Downing JA, Cotner JB, Loiselle SA, Striegl RG, Ballatore TJ, Dillon P, Finlay K, Fortino K, Knoll LB, Kortelainen PL, Kutser T, Larsen S, Laurion I, Leech DM, McCallister SL, McKnight DM, Melack JM, Overholt E, Porter JA, Prairie Y, Renwick WH, Roland F, Sherman BS, Schindler DW, Sobek S, Tremblay A, Vanni MJ, Verschoor AM, Wachenfeldt Ev, Weyhenmeyera GA (2009) Lakes and reservoirs as regulators of carbon cycling and climate. Limnol Oceanogr 54(6, part 2):2298–2314CrossRefGoogle Scholar
- Wahl T (2000) Analyzing ADV data using WinADV. In: Hotchkiss RH, Glade M (eds) Building partnerships. American Society of Civil Engineers, pp 1–10. doi: 10.1061/40517(2000)300
- Yvon-Durocher G, Caffrey JM, Cescatti A, Dossena M, del Giorgio P, Gasol JM, Montoya JM, Pumpanen J, Staehr PA, Trimmer M, Woodward G, Allen AP (2012) Reconciling the temperature dependence of respiration across timescales and ecosystem types. Nature 487(7408):472–476. doi: 10.1038/nature11205 CrossRefPubMedGoogle Scholar