%0 Journal Article
%T Diatoms modify the relationship between dissolved silicon and bicarbonate in the impounded rivers
%A Baoli Wang
%A Benjamin Chetelat
%A Cong-Qiang Liu
%A Fushun Wang
%A Stephen C. Maberly
%J -
%D 2013
%R 10.4081/jlimnol.2013.e40
%X In order to investigate the relationship between dissolved silicon (DSi) and bicarbonate (HCO3每), 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) 每 mainly dominated by carbonate weathering, and Ganjiang 每 mainly dominated by silicate weathering. The DSi: HCO3每 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 HCO3每 was observed and interpreted as the imprint of regional geology on water chemistry. This relationship and the DSi: HCO3每 ratios illustrate the predominant role of carbonate weathering on the riverine HCO3每, even forcatchments where silicate rocks are dominant. In contrast, a cascade of dams in WJ tributary influenced the concentrations of Dsi and HCO3每 and resulted in a positive correlation between DSi and HCO3每. This is because reservoirs allowed populations of diatomsto develop and diatoms stoichiometrically sequestered DSi and HCO3每 causing a negative feedback regulation on the DSi: HCO3每 ratio. Our study demonstrates that the relationship between DSi and HCO3每can reflect not only their geological background but also the influence of algal activity (diatom uptake) within rivers
%K [chemical weathering
%K dam effect
%K diatoms
%K negative regulation
%K Changjiang river.]
%U https://www.jlimnol.it/index.php/jlimnol/article/view/jlimnol.2013.e40