中文摘要：

为了了解微表层浮游植物对氮（N）、磷（P）营养盐的响应,于2013年6月、7月和8月采集了大亚湾海域微表层海水,设置两组N、P浓度梯度（N1：35μmol·L^（-1）,N2：70μmol·L^（-1）,P1：2.2μmol·L^（-1）,P2：4.4μmol·L^（-1））,Si为35μmol·L^（-1）,进行N、P添加的正交实验,观察微表层浮游植物的生长潜力,并在实验开始前、实验中期（培养2—4 d）以及实验结束时（培养7—10 d）测定培养液中无机氮（DIN）、无机磷（DIP）和硅酸盐（DSi）含量.实验结果显,3个月份的微表层水样均以高N高P的N2P2实验组生长最好,而低N低P（N1P1）、低N高P（N1P2）、高N低P（N2P1）组的生长状态相近;而添加单一营养盐的4个实验组（N1、N2、P1、P2）不能促进微表层浮游植物的生长。同时添加N、P后,浮游植物能快速生长,在培养的2—4 d内达到生物量的最高峰.与此同时,营养盐含量也在生长较好的同时添加N、P组迅速下降,特别是在N2P2组中尤为明显,说明浮游植物的快速生长需要消耗大量的营养盐.研究结果表明,自然环境中N、P营养盐的输入能够促使浮游植物生物量迅速增加,而单独添加单一营养盐并不能促使浮游植物的生长。

英文摘要：

Water samples from the sea surface microlayer（SML） were collected from Daya Bay, the South China Sea in June, July and August 2013, respectively. The growth of phytoplankton was studied after adding two levels of nitrogen（N） and phosphorus（P） concentrations（N1： 35 μmol·L^（-1）, N2： 70 μmol·L^（-1）, P1： 2.2 μmol·L^（-1）, P2： 4.4 μmol·L^（-1））. Dissolved inorganic nitrogen（DIN）, phosphorus（DIP） and silica（DSi） in cultures were measured on day 0, day 2—4, and day 7—10. The purpose of this study is to understand the response of phytoplankton in the SML to the addition of nutrients. Results showed that the growth was the best in cultures with high N and P concentrations（N2P2）, and was comparable in cultures of N2P1, N1P2 and N1P1. However the growth could not be accelerated after addition of N or P alone. The biomass of phytoplankton increased rapidly after addition of both N and P, and reached the peak values on day 2—4. Meanwhile, nutrient concentrations decreased greatly in cultures in which both N and P were added, especially in the culture N2P2, indicating that the rapid growth of phytoplankton needed to consume large amounts of nutrients. The results from this study suggested that nutrient loading into natural marine system could accelerate the growth of phytoplankton, however addition of just one nutrient element might not promote the growth.