印度洋浮游植物功能群初级生产调控因子与碳输出效率研究

The major objective of this proposed project is to understand control and fate of phytoplankton production under the unique characteristics of oceanographic processes in the Indian Ocean. We intend to rely on sampling and field works supports from the NSFC Open Science Expedition research cruises of the Indian Ocean. We are trying to answer the following two major questions: 1) How do phytoplankton production and its controlling factors vary across the Indian Ocean and with seasons? 2) What fraction of phytoplankton production is exported to the deep sea, and what are the efficiencies among the different functional groups of phytoplankton in the Indian Ocean? The study will be focused on the following aspects: the Indian Ocean phytoplankton dominant species, communities and primary productivities of different functional groups and carbon cycle related key ecosystem processes, and the efficiencies of key bottom up or top-to-down controlling factors, the varied carbon export efficiency of each phytoplankton functional group, and finally exploring the global warming and ocean surface acidification effects on phytoplankton primary production and carbon export by each functional group in this area. This study is for a further understanding of the processes of biological pump in the upper layer and the export production into the deep ocean, providing some useful information for the academic community to better understand the CO2 emission and carbon sinkin China Seas, and thus providing scientific foundations for the policy makers.

本项目拟依托国家基金委印度洋科学考察共享航次，结合印度洋特有的特征海洋学过程进行相关的海洋浮游植物基础生产与碳循环研究。拟解决1.印度洋浮游植物初级生产的关键控制因素及其时空差异？2.各功能群浮游植物初级生产的效率及向深层海洋输出的效率？这两个关键科学问题。研究内容涉及印度洋浮游植物优势种、群落和各功能群的初级生产效率与碳循环相关重要生态过程及其关键上行效应和下行效应控制因子，各浮游植物功能群的碳沉降输出效率的差异，最后探索全球气候变暖和海洋表层酸化趋势下印度洋浮游植物各功能群的初级生产和碳沉降变化趋势。本研究拟加深对上层水体海洋浮游植物生产和向下输出的生物泵过程理解，为更好地解决中国CO2排放与中国海生物碳汇效率等基础问题提供科学依据。

本项目依托国家基金委印度洋科学考察共享航次，结合印度洋特有的特征海洋学过程进行相关的海洋浮游植物基础生产与碳循环研究。在动印度洋观测了以下参数并获得了初步结果：1)各采样点总叶绿素 a 及分级叶绿素a；2)浮游植物种群结构及不同浮游植物功能群空间分布；3)浮游植物初级生产力；4)浮游植物生长的营养盐限制研究；5)浮游植物生长的浮游动物摄食控制研究；6)蓝藻固氮过程及其对新生产力的贡献；7)颗石藻钙化及其碳循环研究；8)各功能群浮游植物关键物种碳储及其碳累积；9)浮游植物来源透明胞外聚合颗粒物(TEP)及其对碳沉降的贡献；10)浮游动物粪便颗粒及其对碳沉降的贡献；11) 综合分析印度洋上层水体浮游植物初级生产过程调、控及碳沉降输出效率；12) 预测全球变暖和酸化下，印度洋水体浮游植物功能群及其相关碳循环变化趋势。解决了1.印度洋浮游植物初级生产的关键控制因素及其时空差异？2.各功能群浮游植物初级生产的效率及向深层海洋输出的效率？这两个关键科学问题。本研究加深了对上层水体海洋浮游植物生产和向下输出的生物泵过程理解，为更好地解决中国CO2 排放与中国海生物碳汇效率等基础问题提供科学依据。