A Pigment-Based Study of 13C Fractionation in Microalgae: The Effect of Physiological and Environmental Factors on theDelta 13C of POC in the North Atlantic

本研究的目的是探讨环境与生物效应对开放海洋表层POC的相对重要性。13CPOC在海洋中的分布作为纬度的函数不能用任何单一的原因来解释，比如温度、溶解二氧化碳的浓度(ıCO2！Aq)或脂质含量。必须寻求多因果解释来解释这种分布。浮游植物群落组成对海洋中13CPOC分布的影响将被研究，因为不同微藻群之间13C分异的生理特征不同，而且海洋中浮游植物群落的组成随纬度的变化而变化。​13C在实验室和野外不同微藻群中的分离模式将被记录为生长速度、细胞大小和ıCO2!aq的函数。在野外，将类胡萝卜素作为浮游植物群落组成的化学系统指标，通过测量类胡萝卜素的13C来确定不同种类微藻的13C。13CPOC与类胡萝卜素13C之间的关系将在实验室培养中建立。通过比较北大西洋N-S样带不同微藻群中&amp；13CPOC和&amp； 13类胡萝卜素的变化，可以确定浮游植物群落组成对海洋浮游生物&amp；13C的相对影响。

The objective of this research is to investigate the relative importance of environmental vs. biological effects on the &13C of POC in the surface layer of the open ocean. The distribution of &13CPOC in the ocean as a function of latitude can not be explained by any single cause, such as temperature, concentration of dissolved carbon dioxide (ıCO2!aq) or lipid content. Multicausal explanations will have to be sought to explain this distribution. The effects of the composition of the phytoplankton community on the distribution of &13CPOC in the ocean will be investigated since physiological characteristics of 13C fractionation vary among groups of microalgae and the composition of the phytoplankton community varies as a function of latitude in the ocean. Patterns of &13C fractionation in different groups of microalgae in the laboratory and in the field will be documented as a function of growth rate, cell size and ıCO2!aq. In the field carotenoids will be used as chemosystematic indicators for the composition of the phytoplankton community and measure the &13C of carotenoids to determine the &13C of the different groups of microalgae. The relationship between &13CPOC and the &13C of carotenoids will be established for laboratory cultures. A comparison of the variations of &13CPOC and &13Ccarotenoid within the different microalgal groups along a N-S transect in the North Atlantic will establish the relative effect of phytoplankton community composition on the &13C of plankton in the ocean.