南海东北部贫营养海区营养盐对浮游植物生长的限制  

Effects of nutrients on phytoplankton growth in the oligotrophic waters of north-eastern South China Sea

作　　者：李佳俊[1,2] 谭烨辉[2] 周林滨[2] 姜歆[1,2] 赵春宇[1,2] 

机构地区：[1]中国科学院南海海洋研究所海洋生物资源可持续利用重点实验室,广东广州510301 [2]中国科学院大学,北京100049

出　　处：《海洋通报》2016年第5期562-570,共9页Marine Science Bulletin

基　　金：中国科学院海洋专项(XDA11020200);农业行业专项(201403008);国家自然科学基金(41276162);科技基础性工作专项项目(2012FY112400;2013FY111200)

摘　　要：为了探究南海贫营养海区浮游植物的营养盐限制,2014年10月对南海东北部海区进行综合调查,并于陆坡海盆海区设置了不同种类的氮源和同时添加氮磷的实验组进行现场加富培养,观察不同粒径级的叶绿素以及各级主要浮游植物的响应。实验结果显示陆坡海盆海区浮游植物易对同时添加氮磷产生明显响应,浮游植物总叶绿素从0.1 mg/L左右增长到0.6 mg/L以上,且浮游植物加富5 d左右生物量达到最大值。加富营养盐氮磷后微微型(Pico)叶绿素均显著增长,而聚球藻没有出现与Pico级叶绿素同等程度的增长。31、51站各级浮游植物对单一添加氮源后发生一定程度的增长,不同种类的氮源间差异不大。6号站位由于初始浮游植物群落结构及生态环境不同,响应的方式不同于31、51站,磷酸盐对浮游植物生长的促进能力相对更强。另外营养盐添加后,海区浮游植物原有的种群结构发生了改变,尤其是同时添加氮磷组,硅藻成为主要优势种,主要包括绕孢角毛藻Chaetoceros cinctus,小细柱藻Leptocylindrus minimus,中华根管藻Rhizosolenia sinensis等。To investigate the effects of nitrogen（N） and phosphorus（P） on the growth of phytoplankton, nutrient enrich-ment bioassays were carried out on board during the cruise of ＂ Shiyan III＂ in October 2014. In this study, we conducted enrichment experiments at four oceanic stations with different forms of N or mixed N and P. Here, the response of dominant phytoplankton species and size-fractionated Chl a to the addition of different nitrogen species and phosphate were studied.The results showed that phytoplankton increased significantly after the addition of N and P, and reached the maximum about on the fifth day, and the chlorophyll-a（Chl a） concentration increased from about 0.1 mg/l to more than 0.6mg/l. Whereas Synechococcus（Syn） did not increase as much as Pico-Chl a after the enrichment of N and P. At station 31 and 51, phytoplankton also increased（36.5 % and 12 %） in the groups adding N alone by much less than that of adding mixed N and P.Additionally, there was little difference in forms of N. Station 6 was different from others both in the environment and commu-nity structure, where P alone promoted the growth of phytoplankton. After nutrient enrichment phytoplankton succession oc-curred and phytoplankton species were dominated by diatoms, especially in the group enriched with mixed N and P. The dom-inant species included Chaetoceros cinctus, Leptocylindrus minimus and Rhizosolenia sinensis.

关 键 词：南海 浮游植物 营养盐加富 氮磷限制 

分 类 号：Q945.31[生物学—植物学] P737.44[天文地球—海洋地质]