Nitrogen characteristics in sediments of X iangxi B ay, C hina T hree‐ G orge R eservoir

Spatial and temporal distribution characteristics of total nitrogen and ammonium nitrogen in the sediments, pore water and overlying water of X iangxi B ay in C hina T hree‐ G orge R eservoir were investigated. In surveys, the sampling was undertaken from six sites of X iangxi B ay on three dates: 29 M arch 2009, 28 M arch 2010 and 17 A ugust 2010. Mean values of total nitrogen and ammonium nitrogen contents in the sediments and pore water of X iangxi B ay all increased with time, especially in summer. There were intimate relationships between internal nitrogen loading and water ecosystem. Correlation coefficients R were 0.7408 (between total nitrogen in pore water and total nitrogen in sediments) and 0.7483 (between total nitrogen in sediments and chlorophyll‐ a in surface water), respectively. Total nitrogen concentration differences between pore water and overlying water were all positive and had good correlation with chlorophyll‐ a concentration of X iangxi B ay. The release of nitrogen in sediments had an important impact on phytoplankton growth in X iangxi B ay.