@article{Wang_Liu_Wang_Chetelat_Maberly_2013, title={Diatoms modify the relationship between dissolved silicon and bicarbonate in the impounded rivers}, volume={72}, url={https://www.jlimnol.it/jlimnol/article/view/jlimnol.2013.e40}, DOI={10.4081/jlimnol.2013.e40}, abstractNote={<p><em>In order to investigate the relationship between dissolved silicon (DSi) and bicarbonate (HCO<sub>3</sub><sup>–</sup>), we analysed water samples from the main Changjiang channel and its main tributaries in August 2006 and, during 2007-2009, the contrasting tributaries Wujiang (WJ) – mainly dominated by carbonate weathering, and Ganjiang – mainly dominated by silicate weathering. The DSi: HCO<sub>3</sub><sup>–</sup> ratio ranged from 0 to 0.67, which is in agreement with mixing between the weathering of carbonate or silicate. A negative correlation between DSi and HCO<sub>3</sub><sup>– </sup>was observed and interpreted as the imprint of regional geology on water chemistry. </em><em>This relationship and the DSi: HCO<sub>3</sub><sup>–</sup> ratios illustrate the predominant role of carbonate weathering on the riverine HCO<sub>3</sub><sup>–</sup>, even forcatchments where silicate rocks are dominant. In contrast, a cascade of dams in WJ tributary influenced the concentrations of Dsi and HCO<sub>3</sub><sup>–</sup> and resulted in a positive correlation between DSi and HCO<sub>3</sub><sup>–</sup>. This is because reservoirs allowed populations of diatomsto develop and diatoms stoichiometrically sequestered DSi and HCO<sub>3</sub><sup>–</sup> causing a negative feedback regulation on the DSi: HCO<sub>3</sub><sup>–</sup> ratio. Our study demonstrates that the relationship between DSi and HCO<sub>3</sub><sup>–</sup>can reflect not only their geological background but also the influence of algal activity (diatom uptake) within rivers.</em></p>}, number={3}, journal={Journal of Limnology}, author={Wang, Baoli and Liu, Cong-Qiang and Wang, Fushun and Chetelat, Benjamin and Maberly, Stephen C.}, year={2013}, month={Oct.}, pages={e40} }