光合作用是地球碳循环的驱动力，藻类尤其是微藻的光合作用（水体初级生产力）是水圈碳元素由无机到有机的必由之路，是水圈碳循环的最重要的驱动力，而光合电子传递则是微藻体内碳元素微循环的原始驱动力。目前的水体初级生产力分析方法陈旧，不能满足水圈碳循环研究对原位、高灵敏度测定新技术的需求。本项目针对重大研究计划重点资助的水圈碳循环微生物驱动机制和水圈微生物研究新技术方法，在前期大量荧光分析技术和初级生产力研究方法创新的基础上，通过建立水样微藻叶绿素荧光OJIP和荧光光谱与光合色素和光合电子传递活性的函数关系，进一步倒推建立水体初级生产力分析方法模型并进行验证，从而为水圈碳循环的光合驱动力研究提供一条简单、快速、精确、高灵敏度的非损伤、非标记原位分析新技术方法；进而利用该方法分析典型水体初级生产力的时空分布特性，阐明对水圈碳元素循环的贡献和生态意义。

Primary production is the synthesis of organic compounds from atmospheric or aqueous carbon dioxide. It principally occurs through the process of photosynthesis, which uses light as its source of energy. Thus, photosynthesis is considered the drive force of biosphere carbon cycle, while the microalgal photosynthesis, i.e. the water primary production is the driving force of hydrosphere carbon cycle, and makes photosynthetic electron transport the ultimate driving force for micro-carbon-cycle in microalgae. Numerous attempts have been made to estimate the primary production in natural water during the past century, however, all exiting methods were established decades ago and failed to meet the current demand for non-invasive in-situ analysis of water primary productivity. We have previously developed a simplified, rapid, and inexpensive estimation of water primary productivity based on chlorophyll fluorescence parameter Fo. In the proposed project, the fast chlorophyll fluorescence induction dynamics, i.e. the OJIP induction, and the fluorescence excitation spectrum scan techniques will be further applied to establish fast, precise, highly sensitive, non-invasive in-situ analysis methods for water primary productivity analysis. By using the developed new methods, the temporal and spatial distribution of primary productivity of typical water systems will be mapped, thus to elucidate its contribution to hydrosphere carbon cycle.