Effects of artificial thermocline deepening on sedimentation rates and microbial processes in the sediment

摘要: Global warming affects the thermal stratification of freshwater lakes, and thus can lead to thermocline deepening. To follow direct indirect effects shifts on processes at sediment–water interface, thermoclines in six twelve lake enclosures were deepened by pumping warm surface water below thermocline. Hypolimnetic temperatures increased oxygen concentrations decreased due treatment. Path modeling suggests a correlation treatment epilimnetic chlorophytes hypolimnetic diatoms, while dominant cryptophytes cyanobacteria remained unaffected Sedimentation rates, ranging between 0.1 1.9 g m−2 day−1 per enclosure, correlated strongly with selected phytoplankton groups, but not affected Concentrations elements (Ba, Mn, S, Sr), nutrients (NH4 +, PO4 3−, Si), greenhouse gases (CO2, CH4, N2O) upper centimeter sediment changes. Methane carbon dioxide emission from atmosphere negligible. Bacterial viral abundance sediments Results suggest that benthic ecosystem remains slight changes pelagial. Further, we conclude short-term does increase gas emissions temperate, deep, oligo-mesotrophic lakes.