南黄海近岸底栖有孔虫分布与环境因子转换函数的建立

本文对南黄海西北陆架边缘的300个表层沉积物样品中的底栖有孔虫数据,与相应站位的水深、底层水温、盐度、沉积物粒度、有机碳含量等环境参数作了分析研究。除趋势对应分析(DCA)、典型对应分析(CCA)表明有孔虫种群分布与水深、夏季底层水温(Ts)和冬季底层水盐度(Sw)之间存在着显著的数值对应关系。利用加权平均偏最小二乘回归方法(WA-PLS)建立了底栖有孔虫数据与上述环境因子之间的数值转换函数。水深、Ts与Sw转换函数的预测均方根误差(RMSEP)分别是10.8%、11.5%和12.5%,与利用其他指标建立的此类转换函数水平(8%—20%)相当。利用此类统计建模方法建立近岸底栖有孔虫分布与浅海环境因子之间的数值关系是一项新的尝试,结果表明在我国近海底层水体古环境研究中底栖有孔虫转换函数是一种具有一定潜力的研究方法。

BENTHIC FORAMINIFERAL DISTRIBUTIONS AND QUANTITATIVE TRANSFER FUNCTIONS FOR THE SOUTHERN YELLOW SEA INNER SHELF

A database of benthic foraminifera from 300 surface sediments samples and the relevant water depth,bottom-water temperature and salinity,grain size of sediment,organic carbon content from the southern Yellow Sea inner shelf has been compiled.Detrended correspondence analyses(DCA)and canonical correspondence analyses(CCA)of percentage values of benthic foraminifera show strong,statistically significant relationships among modern foraminiferal assemblages,water depth,bottom water summer temperature(Ts)and winter salinity(Sw).Utilising weighted averaging partial least square regression(WA-PLS),transfer functions for water depth,Ts and Sw have been developed.The transfer functions have the similar comparative root-mean-square errors of prediction(expressed as a percentage of the range of the modern environmental gradient sampled)—for water depth,10.8%,for Ts,11.5%,and for Sw,12.5%—compared to transfer functions developed for other proxies elsewhere,which commonly range from 8%to 20%.The research suggested that transfer functions on benthic foraminifera can be a useful new tool in palaeoceanographic and palaeoenvironmental work along the offshore seawaters of China.