Dimensions: Collaborative Research: Biological controls on the ocean C:N:P ratios

维度：合作研究：海洋 C:N:P 比率的生物控制

• 批准号: 1046001
• 负责人: Simon Levin
• 金额: $ 49.74万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-01-01 至 2016-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1046001&HistoricalAwards=false
• 关键词: Dimensions; Collaborative; Research; Biological; controls

Intellectual merit. One of the fundamental patterns of ocean biogeochemistry is the Redfield ratio, linking the stoichiometry of surface plankton with the chemistry of the deep ocean. There is no obvious mechanism for the globally consistent C:N:P ratio of 106:16:1 (Redfield ratio), especially as there is substantial elemental variation among plankton communities in different ocean regions. Thus, knowing how biodiversity regulates the elemental composition of the ocean is important for understanding the ocean and climate as a whole -- now and in the future. The conceptual hypotheses for this study are as follows:1. The C:N:P ratio of a cell is constrained by its broad taxonomic group, which determines, for example, whether it has an outer shell, its size, functional metabolism, membrane lipid composition.2. Within a taxon, there is high genetic diversity. Some of this genetic diversity is potentially laterally transferred, or can be lost within taxa, and confers various functional abilities (organic phosphate assimilation, nitrate assimilation, photoheterotrophy, etc.). Functional diversity provides the cell with further flexibility, such as the ability to respond to varying nutrient supply rates/ratios, and affects a cell's C:N:P ratio within the range specified by the taxon.3. Given these taxonomic and genetic constraints, a cell is physiologically plastic and modifies how it allocates cellular resources in response to nutrient supply rates/ratios in the environment.4. The microbial diversity (taxonomic, genetic, and functional) of the surface ocean varies over time and space, driven by many factors in addition to nutrients. The sum of this mixture composes the ecosystem C:N:P, the ratio that Redfield described. Based on this framework, the CoPIs will make field observations of taxon-specific stoichiometry and growth rates, genomic analyses, and conduct laboratory chemostat experiments to improve understanding of how ocean taxonomic, genetic, and functional biodiversity control the stoichiometry of the surface ocean plankton. Their analyses of these data would lead to a mechanistic understanding of variations in the Redfield ratio, both spatially and temporally.Broader impacts. This study will greatly expand knowledge of the genomic diversity among ocean microbes and how this diversity affects biogeochemistry. The stoichiometry of the ocean's microbes is a parameter that nearly every chemical or biological oceanographer uses, from converting measurements made in one element to another, to estimating regional and global nitrogen budgets. The research also has important implications for the global carbon budget and any changes that might result from climate change. Beyond training three postdoctoral scholars and two graduate students, a Gateway Mentoring Program will be established to recruit undergraduates (total of 12) transferring from community colleges in the Southern California area, training and preparing them for careers in research-oriented science. The program will consist of extensive mentoring, research experiences at UCI, internships at BIOS, Princeton, or UCSD, and presentations at national conferences. This intensive mentoring and research experience prepares students well for a career in science, and enhances acceptance to post-graduate schools. The Program will have a very high proportion of underrepresented groups as reflected in the targeted colleges.Integration. To understand mechanistically temporal and spatial variability of the plankton C:N:P ratio, biodiversity must be studied not only at the traditional taxonomic level, but at the genetic and functional levels which dictate organism response to their environment. Data will be integrated into a combined ocean ecological, evolutionary, and biogeochemical model, with flexible stoichiometry, including cellular biochemical allocations. Seeding a coupled physical-biological model of the oceans with multiple competing genotypes enables the exploration of ecological and evolutionary patterns of resource acquisition and C:N:P ratios. Developing a more mechanistic examination of the course of ecology and evolution, in which laboratory and field data define tradeoffs between different growth and nutrient acquisition strategies, would estabblish the framework of adaptive dynamics for determining "evolutionarily convergence". Finally, model outcomes will be evaluated against field data.

智力优点。海洋生物地球化学的基本模式之一是雷德菲尔德比率，将表面浮游生物的化学计量与深海的化学计量联系起来。全球一致的C：N：P比为106：16：1（红场比）没有明显的机制，尤其是因为不同海洋地区浮游生物群落之间存在实质元素变化。 因此，知道生物多样性如何调节海洋的元素组成对于理解整个海洋和气候 - 现在和将来很重要。这项研究的概念假设如下：1。 细胞的C：n：p比受其广泛的分类群的约束，例如，它决定它是否具有外壳，大小，功能代谢，膜脂质组成2。 在分类单元中，存在很高的遗传多样性。 这种遗传多样性中的某些可能是侧向转移的，或者可能在分类单元中丢失，并赋予各种功能能力（有机磷酸盐同化，硝酸盐同化，光透明质营养等）。 功能多样性为细胞提供了进一步的灵活性，例如能够响应不同的养分供应率/比率，并影响细胞的C：N：P比在本类别分类范围内指定的范围内。3。 鉴于这些分类学和遗传约束，细胞在生理上是塑料的，并修改了如何根据环境中的营养供应率/比率分配细胞资源。4。 表面海洋的微生物多样性（分类，遗传和功能）随着时间和空间的变化，除了营养外，许多因素驱动。 该混合物的总和组成了Redfield所描述的比率。 基于此框架，COPI将对分类群特异性化学计量和生长速率，基因组分析以及进行实验室化学仪的实验实验，以提高对海洋分类，遗传和功能生物多样性如何控制表面海洋plankton表面的量学计量法。 他们对这些数据的分析将导致对红场比的变化的机械理解，无论是在空间还是时间上。 这项研究将大大扩展人们对海洋微生物之间基因组多样性的了解，以及这种多样性如何影响生物地球化学。 海洋微生物的化学计量是一个参数，几乎每个化学或生物海洋学家都使用的参数，从将一个元素的转换测量到另一种元素进行，到估计区域和全球氮预算。 这项研究对全球碳预算以及气候变化可能导致的任何变化也具有重要意义。 除了培训三名博士后学者和两名研究生外，还将建立一项门户指导计划，以招募本科生（总共12个）从南加州地区的社区学院转学，并为研究面向研究的科学的职业进行培训和准备。该计划将包括广泛的指导，在UCI的研究经验，在BIOS，Princeton或UCSD的实习以及在国家会议上的演讲。 这种密集的指导和研究经验为学生做好了很好的准备，从事科学职业，并增强了对研究生学校的接受。 该计划将在目标大学中所反映的人数不足的群体比例很高。 要了解浮游生物C：N：P比的机械时间和空间变异性，不仅必须在传统的分类水平上研究生物多样性，而且还必须研究遗传和功能水平，这决定了有机体对环境的反应。 数据将集成到具有柔性化学计量的海洋生态，进化和生物地球化学模型中，包括细胞生化分配。 用多种竞争基因型播种海洋的耦合物理生物学模型，可以探索资源获取的生态和进化模式以及C：N：P比。 对生态和进化的进化进化进行了更机械的研究，其中实验室和现场数据定义了不同生长和养分获取策略之间的权衡，将揭示自适应动态的框架，以确定“进化上的融合”。 最后，将根据现场数据评估模型结果。