We collected two lake sediment cores （MC and DM） from the East Antarctic region for analysis of biogenic silica and other biogeochemical parameters （e.g., organic matter, C, N, S, H）. Based on synthetically compar...We collected two lake sediment cores （MC and DM） from the East Antarctic region for analysis of biogenic silica and other biogeochemical parameters （e.g., organic matter, C, N, S, H）. Based on synthetically comparative research, we focused on the potential application of biogenic silica （BSi） for the reconstruction of paleo-primary productivity in the East Antarctic lakes. Analytical results showed that a large number of diatoms were well preserved in the freshwater lake sediments, and that concentrations of biogenic silica displayed notable fluctuations over different water depths. The content of biogenic silica had a consistent profile over water depth, and this pattern changed with organic matter, reflecting their potential as eco-environmental proxies. Low lev- els of BSi and organic matter indicated reduction of lake algal production, and corresponded to decreased lake primary productivity. Due to the fragile ecosystem state and limited contribution of terrestrinl organic matter in the East Antarctic lakes, the contents of biogenic silica in the lacustrine sediments can sensitively indicate the evolutionary history of paleo-primary productivity. Overall, BSi is an ideal proxy for the reconstruction of past eeo-environmental change recorded in the lacustrine sediments on East Antarctica.展开更多
Basic data of radiolarian group and primary productivity were from 46 investigation stations of the South China Sea. The factor analysis of principal component and the least squares estimation in both linear regressio...Basic data of radiolarian group and primary productivity were from 46 investigation stations of the South China Sea. The factor analysis of principal component and the least squares estimation in both linear regression and nonlinear estimation were applied to establishing the radiolarian transfer function for paleo-primary productivity in this sea area. The results show that the transfer function of nonlinear regression analysis for the radiolarian assemblage and primary productivity has much better parameters. Factors analysis has accumulating variance of 83.6% and communalities of more than 0.940347. Nonlinear regression analysis gives multiple correlation coefficient as 0.84888 and explained variance as 72.059%. The equation of transfer function is with an average estimated error of about 53.778 mg·C/m^2·d, which is 14.69% in average observed values. Calculation accuracy is 85.31% for the system of transfer function.展开更多
基金supported by the National Natural Science Foundation of China (Grant nos.40876096,41076123 and 40606003)the Open Research Funds from SOA Key Laboratory for Polar Science (Grant no.KP2007002)a special fund for excellent PhD thesis of CAS
文摘We collected two lake sediment cores （MC and DM） from the East Antarctic region for analysis of biogenic silica and other biogeochemical parameters （e.g., organic matter, C, N, S, H）. Based on synthetically comparative research, we focused on the potential application of biogenic silica （BSi） for the reconstruction of paleo-primary productivity in the East Antarctic lakes. Analytical results showed that a large number of diatoms were well preserved in the freshwater lake sediments, and that concentrations of biogenic silica displayed notable fluctuations over different water depths. The content of biogenic silica had a consistent profile over water depth, and this pattern changed with organic matter, reflecting their potential as eco-environmental proxies. Low lev- els of BSi and organic matter indicated reduction of lake algal production, and corresponded to decreased lake primary productivity. Due to the fragile ecosystem state and limited contribution of terrestrinl organic matter in the East Antarctic lakes, the contents of biogenic silica in the lacustrine sediments can sensitively indicate the evolutionary history of paleo-primary productivity. Overall, BSi is an ideal proxy for the reconstruction of past eeo-environmental change recorded in the lacustrine sediments on East Antarctica.
文摘Basic data of radiolarian group and primary productivity were from 46 investigation stations of the South China Sea. The factor analysis of principal component and the least squares estimation in both linear regression and nonlinear estimation were applied to establishing the radiolarian transfer function for paleo-primary productivity in this sea area. The results show that the transfer function of nonlinear regression analysis for the radiolarian assemblage and primary productivity has much better parameters. Factors analysis has accumulating variance of 83.6% and communalities of more than 0.940347. Nonlinear regression analysis gives multiple correlation coefficient as 0.84888 and explained variance as 72.059%. The equation of transfer function is with an average estimated error of about 53.778 mg·C/m^2·d, which is 14.69% in average observed values. Calculation accuracy is 85.31% for the system of transfer function.
