Biogeosciences, 10, 7539–7551, 2013 Open Access www.biogeosciences.net/10/7539/2013/ doi:10.5194/bg-10-7539-2013 Biogeosciences © Author(s) 2013. CC Attribution 3.0 License. Regulation of CO2 emissions from temperate streams and reservoirs S. Halbedel and M. Koschorreck Department Lake Research, Helmholtz Centre for Environmental Research – UFZ, Brückstrasse 3a, 39114 Magdeburg, Germany Correspondence to: S. Halbedel (
[email protected]) Received: 28 May 2013 – Published in Biogeosciences Discuss.: 20 June 2013 Revised: 18 October 2013 – Accepted: 24 October 2013 – Published: 22 November 2013 Abstract. It has become more and more evident that CO2 less relevant in low-wind lakes. Under high-wind conditions, emission (FCO2 ) from freshwater systems is an important however, k regulates FCO2 from lotic systems as well. We part of the global carbon cycle. To date, only a few studies developed a theoretical framework describing the role of the have addressed the different mechanisms that regulate FCO2 different regulation mechanisms for FCO2 from streams and in lotic and lentic systems. In a comparative study we in- lakes. vestigated how different biogeochemical and physical fac- In summary, the dominant factor affecting FCO2 is the tors can affect FCO2 values in streams and reservoirs. We ex- concentration of CO2 in the surface water. Lake stratifica- amined the seasonal variability in CO2 concentrations and tion has a very important regulatory effect on FCO2 from emissions from four streams and two pre-dams of a large lakes on account of its influence on CO2 concentrations drinking water reservoir located in the same catchment, and and metabolic processes.