生态环境学报2011，Vol.20Issue(12)：1902-1908,7.
不同溶氧条件下九龙江口湿地沉积物-水界面氨氮释放与氧化规律
The release and oxidation of ammonia at the sediment-water interface of Jiulong River Estuary wetland under different oxygen conditions
摘要
Abstract
The release and oxidation of NH4+-N in the intertidal sediments is a critical process of the nitrogen biogeochemical cycle in the estuarine wetland ecosystems. This study investigated the release and oxidation mechanisms of NH4+-N at the sediment-water interface of two kinds of Jiulong River Estuary Wetland sediments under four dissolved oxygen conditions (saturated, aerobic, anoxic and anaerobic). The results showed that the ways of NH4+-N release and oxidation in two sediments with different vegetation were significantly different under four dissolved oxygen conditions. Firstly, the release of NH4+-N from mangrove sediment to overlying water was 0.9～3.5 times than mudflat sediments, and the release of NH4+-N from mangrove sediments to overlying water were 1.64 mg (saturated), 2.07 mg (aerobic), 3.47 mg (anoxic) and 3.20 mg(anaerobic), respectively;while from mudflat sediments they were 0.85 mg, 1.00 mg, 0.77 mg and 1.27 mg, respectively. The amount of sediment NH4+-N release was low at high DO condition, but high at low DO condition. Secondly, the release rate and oxidation rate of NH4+-N in the mangrove sediments were 43.73～48.51 mgN·m-2-d·-1 and 26.19～40.68 mgN·m-2·d-1, respectively, which were higher than that (14.50～19.22 mgN·m-2·d-1 and 8.35-22.53 mgN·m-2·d-1) in the mudflat sediments. The reason was possibly that the microorganism species in mangrove sediments were richer than mudflat sediments, resulting in the higher degree of the mineralization and nitrification in mangrove sediments. This study revealed the transfer and transformation of NH4+-N in two sediments under different gradients of dissolved oxygen, which would benefit the decision-making process for the protection of coastal wetlands and the control of coastal water eutrophication.关键词
河口湿地/溶氧/释放/氧化/沉积物-水界面/氮Key words
estuarine wetland/DO/release/oxidation/sediment-water interface/nitrogen分类
资源环境引用本文复制引用
邱昭政,颜昌宙,赵艳玲,杜苗苗,罗专溪..不同溶氧条件下九龙江口湿地沉积物-水界面氨氮释放与氧化规律[J].生态环境学报,2011,20(12):1902-1908,7.基金项目
中国科学院知识创新工程重要方向项目(KZCX2-YW-Q02-04) （KZCX2-YW-Q02-04）
