WEI Yu1,2, YANG Changping3, LIU Zaihua1, YAN Hao1
（1.State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang , 550002, China;
2.University of Chinese Academy of Sciences, Beijing 100049, China;
3. School of Chemical Engineering, Guizhou Institute of Technology, Guiyang 550003, China; ）
Abstract: We studied carbon and silicon cycles in Hongfeng Lake, Puding Reservoir and Pingzhai Reservoir and discussed the coupled cycling of carbon and silicon. Photosynthesis caused depletions of dissolved silicon (DSi) and dissolved inorganic carbon (DIC) in the surface water of reservoirs. When the DSi supply is limited, DSi is utilized by diatom and the DSi depletion will happen. Concentrations of organic carbon (OC) and biogenic silicon (BSi) increase when the contribution of autochthonous organic carbon (OCauto) to settled particles increases, the OC/BSi ratio is controlled and relates negatively with the contribution of diatom to OC. The K value (K=BSi/OC), which positively relates with the contribution of diatom to OC, can be used as an indicator of the contribution of diatom to OC. The Kauto (Kauto=BSi/OCauto) relates positively with the eutrophication degree and can be regard as an indicator of the degree of eutrophication.
Key words: karst reservoir; carbon cycle; silica cycle; biogenic silica
EARTH AND ENVIRONMENT Vol.48, No.1, Tot No.333, 2020, Page 1-9
