厦门港表层水体磷周转的生物学过程Ⅱ：桡足类对浮游植物的摄食压力

为了解桡足类在磷的生物地球化学循环中的作用，于2005年5、8、11月和2006年3月分别在厦门时间序列站（XMTS）采用肠道色素法，研究了桡足类对浮游植物的现场摄食率，同步分析了桡足类的种类组成和数量变化，进而得到桡足类群体对浮游植物的摄食率.结果表明：厦门港桡足类对浮游植物的年平均摄食率为55.53 μg·m^-3·d^-1;其中秋季最高，为108.98 μg·m^-3·d^-1，夏季最低，为7.18 μg·m^-3·d^-1.根据试验数据估算，厦门港桡足类对浮游植物现存量的摄食压力四季平均为1.81%，春、夏、秋、冬分别为3.22%、0.06%、3.52%和0.46%.

Biological process of phosphorus turnover in surface water body of Xiamen Harbor.Ⅱ:Grazing pressure of copepod on phytoplankton

To understand the roles of copepod in the biogeochemical cycling of phosphorus, gut fluorescence method was applied to examine in situ the grazing rate of copepod on the phytoplankton in Xiamen Time Station (XMTS) in May, August and November 2005 and March 2006. In the meanwhile, the abundance and species composition of copepod were investigated, and the grazing pressure of copepod on the phytoplankton was estimated. The results showed that the annual average grazing rate of copepod was 55.53 μg·m^-3·d^-1, being the highest (108.98 μg·m^-3·d^-1) in autumn and the lowest (7.18 μg·m^-3·d^-1) in summer. Based on the estimation from our experimental data, the daily grazing rate of copepod populations on the phytoplankton in Xiamen Harbor was, on annual average, about 181% of the phytoplankton’s standing stock, with the values in spring, summer, autumn, and winter being 3.22%, 0.06%, 3.52% and 0.46%, respectively.