南京林业大学学报（自然科学版）2016，Vol.40Issue(2)：9-15,7.DOI:10.3969/j.issn.1000-2006.2016.02.002
典型滨海湿地沉积物反硝化与硝态氮氨化相对重要性研究
The relative importance of dissimilatory nitrate reduction to ammonium and denitrification in sediments in a typical coastal wetland
摘要
Abstract
This study aims to investigate nitrate reduction in sediments in a typical coastal wetland. Sediment samples were taken in different season and in different vegetation conditions ( Phragmites australis, Spartina alterniflora commu⁃nity, the intergrowth area of the two species and mudflat) in Chongming Dongtan wetland in the Yangtze River Delta of China. Rates of dissimilatory nitrate reduction to ammonium ( DNRA) and denitrification ( Den) were estimated using 15 N isotope dilution technique to detect the relative importance of the two reduction processes. Results showed that:① Den rates in Spartina alterniflora community arrived to 31.29 μg/(kg·h) in winter, which was the highest among four vegetation communities ( P<0�05) . In contrast, this rates decreased to a very low range of 2.35-3.36 μg/( kg·h) in other three seasons. It revealed that there was a potential high amount of N loss via Den in winter in Spartina alterni⁃flora community.②DNRA rates in the mudflat (>120μg/( kg·h) ) were much higher than those observed in vegetation community (<80 μg/( kg·h ) ) in spring and winter. For different vegetations, the rate in Spartina alterniflora community was the highest (P<0.05). In contrast, DNRA rates in sediments without vegetation were lower than those with vegetation in summer and autumn, and no significant difference among three communities was found. This suggested that Spartina alterniflora possibly facilitates DNRA in spring and winter. ③The ratios of DNRA and Den in Spartina al⁃ terniflora community ( 17-29) were much higher than those in the other vegetations ( 1-14) in spring, summer and au⁃tumn. However, in winter, this ratios were lower than the others ( P<0.05) . Therefore, DNRA dominates the reduction of nitrate in the coastal wetland. It would be very necessary to control of eutrification and N2 O emission to reduce Sparti⁃na alterniflora in a coastal wetland. It is effective to control eutripication and to reduce N2 O emission via reducing S. al⁃terniflora in coastal metlands.关键词
滨海湿地/反硝化/硝态氮氨化/15 N/互花米草Key words
coastal wetland/denitrification/dissimilatory nitrate reduction to ammonium/15 N/Spartina alterniflora分类
资源环境引用本文复制引用
徐莎,陈圆,印杰,韩建刚,薛建辉..典型滨海湿地沉积物反硝化与硝态氮氨化相对重要性研究[J].南京林业大学学报（自然科学版）,2016,40(2):9-15,7.基金项目
国家自然科学基金项目（41375149）；国家林业公益性行业科研专项项目（201404305）；江苏高校优势学科建设工程资助项目 （）
