南海氮循环几个重要过程研究的新进展

(厦门大学 海洋与地球学院,近海海洋环境科学国家重点实验室,福建 厦门 361102)

南海; 海洋氮循环; 外源氮; 颗粒氮动力学; 氨氮动力学

Recent Progresses in Some Important Processes of Nitrogen Cycle in the South China Sea
YANG Jinyu*,GAO Shuji

(State Key Laboratory of Marine Environmental Science,College of Ocean and Earth Sciences,Xiamen University,Xiamen 361102,China)

South China Sea; marine nitrogen cycle; external nitrogen; particulate nitrogen dynamics; ammonium dynamics

DOI: 10.6043/j.issn.0438-0479.201807032

备注

边缘海连接陆地和开阔大洋,是氮循环过程非常活跃和复杂的区域.南海是世界上最大的边缘海之一,是研究边缘海氮循环的热点区域.重点总结和归纳了南海外源氮输入、上层水体氨氮动力学过程和水体颗粒氮动力学过程的新进展:南海氮循环过程广泛受到人为活动的影响,表现为人为排放进入南海的外源氮持续增加; 南海上层水体氨氮的动力学过程与营养盐跃层有关,并受到黑潮入侵的影响; 上层水体中不同颗粒氮同位素信号高度相似,表明氮元素的快速运转; 有别于其他陆架边缘海,南海颗粒氮同位素特征在向下传输过程中存在显著改变.

Marginal seas,connecting land and open ocean,are the regions in which nitrogen cycle processes are highly dynamic and complicated.The South China Sea(SCS)is one of the biggest marginal seas in the world,which becomes one of the hot-spot regions for the study on nitrogen cycle.Here,recent research progresses in the processes of N sources and sinks,as well as the N internal cycle in the SCS are summarized,which is specifically focused on supply of external nitrogen,ammonium consumption in the euphotic zone,and particulate nitrogen dynamics in the water column.External nitrogen inputs have increased during recent decades mainly due to human activities.Ammonium dynamics is associated with the nitracline depth,and is also influenced by the intrusion of Kuroshio waters.High similarity in nitrogen isotopes among various types of particles in the euphotic zone implies rapid N turnover in the ecosystem.The significant change in particulate N isotope during its downward transfer makes the SCS different from most other marginal seas.