太湖东北部沉积物可溶性氮、磷的季节性变化

Seansonal variation of dissolved nitrogen and phosphorus in sediments in northeast part of Lake Taihu

通过快速释放实验,研究了太湖东北部营养水平不同的梅梁湾、贡湖湾和胥口湾3个湖区表层沉积物中可溶性氮、磷的季节性变化.结果表明,沉积物总磷(TP)与其释放的可溶性总磷(DTP)在春、夏两季显著相关并且以可溶性有机磷(DOP)为主;春、夏两季DOP与可溶性无机磷(DIP)的形态间转化较秋、冬两季更为活跃.藻型湖区沉积物的总氮(TN)多为夏季减少,而清洁型湖区则为夏季大幅增加;沉积物释放的NH4+-N以夏、冬两季居多,夏季达到最大值;沉积物释放的NO3--N夏季大幅度增加,冬季较少.清洁型湖区夏季沉积物的TN及其释放的NH4+-N、NO3--N显著高于藻型湖区.

The seasonal variation of dissolved nitrogen and phosphorus in the surface sediments from 3 lake regions of gulfs of Meiliang, Gonghu and Xukou of different trophic levels in the northeast part of Lake Taihu were studied through rapid release experiment. There was significant correlation between total phosphorus （TP） and its released dissolved total phosphorus （DTP） in spring and summer, and dissolved organic phosphorus （DOP） was the main one. The form transformation of DOP and dissolved inorganic phosphorus （DIP） was more active in spring and summer than autumn and winter. The total nitrogen （TN） of the sediments of alga type lake region decreased in summer, and increased greatly in sediments of cleen type lake region in summer. The NH4^＋-N released from sediments was higher in summer and winter, and reached the greatest value in summer; the NO3^- -N released from sediments in summer increased greatly and little relatively in winter. The TN of sediments in summer and its released NH4^＋ -N, NO3^--N in the clean type region was higher markedly than these in the alga type region.