南海水域生物固氮作用研究进展

Research Progresses in Biological Nitrogen Fixation in the South China Sea

生物固氮作用影响海洋氮收支平衡并调控初级生产力,是海洋氮循环研究的热点之一.南海是位于西太平洋的重要的边缘海,被认为是具备生物固氮作用的理想环境.为了对南海水域生物固氮作用研究有一个全面了解,尝试梳理南海生物固氮作用研究的相关结果,并对南海固氮作用的研究进行了展望.南海固氮生物组成较为复杂,具有较大的时空可变性.南海的固氮速率与其他热带、亚热带海区相近,其中海盆区的年固氮量可达3.6×107 mol/a.整体而言,生物固氮作用对南海初级生产力的贡献并不显著.营养盐调控、黑潮流入侵、大型河流羽状流区的影响等因素,都在很大程度上影响着南海固氮作用的时空分布.

N 2 fixation plays an essential role in the nitrogen budget and sustains the primary production in the oceans.The South China Sea is an important marginal sea in the western Pacific Ocean,which is characterized by high temperature and oligotrophic environment.It has been considered as an ideal environment for N 2 fixation.Research of N 2 fixation in the South China Sea has been carried out for nearly 20 years.The diazotrophic composition in the South China Sea is complex,with large spatial/temporal variability.The annual flux of N 2 fixation in the central basin of the South China Sea is estimated to be 3.6×10 7 mol/a.Generally,N 2 fixation is not the major N-contributor to the primary production in the South China Sea.Processes such as nutrient regulation,Kuroshio intrusion and large river plumes may be important controlling factors in shaping the spatial/temporal patterns of N 2 fixation in the South China Sea.