JGOFS-Synthesis: The Role of Phytoplankton Community Structure in Determining Particulate Elemental Composition, Carbon Fixation and Bio-Optical Properties

JGOFS-Synthesis：浮游植物群落结构在确定颗粒元素组成、碳固定和生物光学特性中的作用

• 批准号: 9904687
• 负责人: Giacomo DiTullio
• 金额: $ 8.76万
• 依托单位: College of Charleston
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-07-01 至 2002-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9904687&HistoricalAwards=false
• 关键词: JGOFS; Synthesis; Role; Phytoplankton; Community

DiTullioPhytoplankton community structure and biogeography have been identified as key gaps in the knowledge needed to progress from current ocean biogeochemistry models (with generic phytoplankton parameterizations) to more explicit models. In particular, deviations from generic phytoplankton descriptions may be greatest during episodic blooms of a few species, and in some regions these episodic events are associated with rapid flux of particulate carbon to the seafloor, distinct biogeochemical processes (e.g., N-fixation, carbonate precipitation, dimethylsulfide production), or shifts in elemental composition of particulate matter. Thus, future biogeochemical models may need to shift parameterizations to reflect biogeographic regions and/or seasonal blooms. During the JGOFS era, High-Performance-Liquid-Chromatography (HPLC) methods for characterizing phytoplankton pigments were used widely, and these data sets can be used to make a first-order approximation of phytoplankton community structure. This project will analyze HPLC pigment data sets collected worldwide to develop algorithms (on event, regional, and global scales) for estimating phytoplankton community structure. The estimates of phytoplankton community structure from HPLC pigments will be compared to microscopy and flow-cytometry data, when available, to test the validity of these new algorithms. Drs. Lizotte and DiTullio will compile and synthesize data sets to study biogeographical distributions of phytoplankton. They will also extract subsets of the data for samples dominated by single taxonomic groups (e.g., diatoms, coccolithophorids, picocyanobacteria, Phaeocystis spp.) to determine whether other phytoplankton-related parameters are correlated with community structure. The ancillary data sets compiled for phytoplankton-related parameters will be those most useful for developing SMP biogeochemical models and for remote sensing of phytoplankton biomass (e.g. particulate carbon, nitrogen, and absorbance; carbon:chlorophyll a ratios; photosynthetic rates; photosynthesis-irradiance parameters and quantum yields; nutrient utilization indices and ratios; light attenuation; reflectance ratios; and water column stability).

DiTullio浮游植物群落结构和浮游植物地理学已被确定为从目前的海洋生物地球化学模型（通用浮游植物参数化）进展到更明确的模型所需知识的关键差距。特别是，在少数物种的间歇性水华期间，与一般浮游植物描述的偏差可能最大，在某些区域，这些间歇性事件与颗粒碳快速流入海底、独特的海洋地球化学过程（例如，固氮、碳酸盐沉淀、二甲硫醚生成）或颗粒物元素组成的变化。因此，未来的地球化学模型可能需要改变参数化，以反映地理区域和/或季节性水华。在JGOFS时代，用于表征浮游植物色素的高效液相色谱（HPLC）方法被广泛使用，这些数据集可以用来对浮游植物群落结构进行一级近似。该项目将分析在全球范围内收集的HPLC色素数据集，以开发用于估计浮游植物群落结构的算法（在事件，区域和全球尺度上）。从HPLC色素浮游植物群落结构的估计将进行比较，显微镜和流式细胞术的数据，当可用时，测试这些新算法的有效性。Lizotte和DiTullio博士将汇编和综合数据集，以研究浮游植物的地理分布。他们还将提取由单一分类群主导的样本的数据子集（例如，硅藻、颗石藻、微蓝细菌、棕囊藻属）以确定其他植物生长调节剂相关参数是否与群落结构相关。为与浮游植物有关的参数汇编的辅助数据集将是那些对开发SMP生物地球化学模型和遥感浮游植物生物量最有用的数据集（例如，颗粒碳、氮和吸收率;碳：叶绿素a比率;光合作用速率;光合作用-辐照参数和量子产额;养分利用指数和比率;光衰减;反射率;以及水柱稳定性）。