SGER: The Oxygen Isotope Ratio of Organic Phosphorus Compounds What controles the isotopic fractionation? A first step towards a new proxy

这个P.I.将探索有机磷化合物（d18Oop）的氧同位素系统作为确定光带内群落磷利用率的工具的效用。海洋磷(P)的生物地球化学循环与大气中二氧化碳的丰度有着复杂的联系，因为它是一种重要的主要营养物质，可能是地质时间尺度上的最终限制营养物质。与氮和硅不同，磷只有一种稳定同位素，因此与磷酸盐利用有关的同位素分馏尚未应用于该体系。这将通过(1)旨在确定影响d18Oop的环境因素（温度、磷酸盐浓度、生长水和食物来源的d18O、物种组成和生长速度）的培养实验来完成，(2)旨在评估与分析过程相关的潜在人工制品的实验。这个提议有可能提供一个独特而有力的工具来研究现在和过去的磷利用和循环，以及它在空间和时间上的变化以及与全球气候变化的关系。

This P.I. will explore the utility of oxygen isotope systematics in organic P compounds (d18Oop) as a tool for determining community P utilization rate within the euphotic zone. The marine biogeochemical cycle of phosphorus (P) is intricately linked to the atmospheric abundance of CO2 through its role as an important major nutrient and possibly the ultimate limiting nutrient on geological time scales. Unlike nitrogen and silica phosphorus has only one stable isotope and thus isotopic fractionations related to phosphate utilization has not been applied to this system. This would be done by (1) culture experiments geared toward determining the environmental factors (temperature, phosphate concentrations, d18O of growth water and food source, species composition and growth rate) affecting the d18Oop and, (2) experiments designed to evaluate potential artifacts associated with the analytical procedure. This proposal has the potential to provide a unique and powerful tool to investigate present and past P utilization and cycling, and how this might have changed in space and time and in relation to global climate change.