全球海洋初级生产力和碳吸收能力估算中常被忽略的浮游植物光合溶解有机碳生产对于海洋碳循环和碳收支模型的建立具有重要的科学意义。本项目围绕“浮游植物光合溶解有机碳生产及其环境调控机制”的科学问题，以北太平洋西部的日本东部海域为现场研究海域，通过大面调查、现场培养实验，从生态响应方面，研究浮游植物生物量和生产力粒级结构、浮游植物和异氧细菌的时空分布特征，探讨关键生物参数对光合溶解有机碳释放的影响；从生物泵储碳贡献角度，分析颗粒有机碳生产力、新生产力和异氧细菌生产力与溶解有机碳生产的关系，探讨光合溶解有机碳生产对总生产力的贡献；辅以室内实验手段，研究海洋环境因子对溶解有机碳生产的影响，探讨溶解有机碳生产与关键生物地球化学过程的耦合关系，揭示溶解有机碳生产对海洋环境变动的响应机理。该研究可应用于海域浮游植物固碳量的修正，并将为海洋碳循环和海洋生态系统食物网营养动力学研究提供重要的基础参数和科学依据。

Photosynthetically produced dissolved organic carbon (PDOC) released of marine phytoplankton，which is often neglected in the estimation of global marine primary productivity and carbon sequestration capacity，has an important scientific significance on marine carbon cycle as well as carbon balance model-building.This project will be thoroughly studied the issue on PDOC released of marine phytoplankton and its environmental regulation mechanism by carrying out field studies in the Japanese eastern sea of the western North Pacific.Through large scale investigation and field cultivation experiment，this project is intended to，in terms of ecological response，illustrate the temporal and spatial distribution of both size-fraction of phytoplankton biomass and productivity as well as both phytoplankton and heterotrophic bacterica respectively to further discuss the influence of key marine biological parameters on PDOC released of marine phytoplankton.The relationships between photosynthetically produced particulate organic carbon (PPOC) productivity and PDOC productivity，between new productivity and PDOC productivity as well as between heterotrophic bacteria productivity and PDOC productivity will be analyzed respectively in terms of biological pump contributions in carbon sequestration.Meanwhile，the contribution of PDOC productivity to total primary productivity will be studied. This project is intended to reveal the PDOC productivity response mechanism to marine environment changes through exploring the influence of marine environment factors on PDOC productivity and investigating the coupling between PDOC productivity and key biogeochemical process，which will be supplemented by lab experiment methods.This study can be applied to the correction of phytoplankton carbon sequestration amount and will provide vital basic parameter and scientific basis for marine carbon cycle and nutrition dynamics on marine ecosystems and food webs.