Doctoral Dissertation Research: Determining the functional relationship between simultaneous co-limitating light and nutrient conditions on phytoplankton growth

博士论文研究：确定同时共同限制光和营养条件对浮游植物生长的函数关系

• 批准号: 2112976
• 负责人: Kevin Arrigo
• 金额: $ 4.35万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2112976&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Determining; functional; Doctoral; Dissertation; Research; Determining; functional

The growth rate of phytoplankton, single-celled marine algae that take up carbon dioxide and produce oxygen, is controlled in the ocean by the availability of both light and nutrients. However, no laboratory study has generated the data required to quantify how nutrient and light interact to control phytoplankton growth. Some models assume that light and nutrients act independently to control phytoplankton growth, while others assume that light and nutrients act in concert. These two different assumptions about how light and nutrients control phytoplankton growth can produce vastly different predictions about the speed of this process and the magnitude of phytoplankton blooms. The researchers will use a series of laboratory experiments to determine if the effects of nutrients and light on phytoplankton growth is best modeled assuming that the two limiting resources act independently or in concert. This experiment will help to improve marine ecosystem models implemented throughout the world’s oceans, but will be particularly relevant in the Arctic, where light and nutrient availability are both rapidly changing as a result of anthropogenic climate change.The researchers will grow Arctic diatoms across a range of growth-limiting nitrate (NO3-) and light conditions. Individual cultures will be maintained under constant temperature, light, and nutrient conditions in chemostats. There will be 25 unique interacting NO3- and light-limited treatment combinations conducted using five light and five NO3- conditions, as well as five additional treatments at light-saturated but NO3- deplete conditions. Following acclimation of cultures to the treatments, the researchers will measure phytoplankton biomass and photosynthesis vs. irradiance (P-E) relationships, and phytoplankton growth rates will be determined from the dilution rate of the media. Light and nutrient limitation terms will then be calculated for each treatment. Finally, the best functional relationship that best describes the relationship between co-limiting light and nutrient conditions will be determined by comparing the two established (minimum and multiplicative) relationships to a variety of non-linear relationships between the limitation terms.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

通过光和营养物质的可用性控制了占二氧化碳并产生氧气的浮游植物，单细胞海藻的生长速率。但是，没有实验室研究生成所需的数据来量化营养和光的相互作用以控制浮游植物的生长。一些模型假设光和营养物质独立起作用以控制浮游植物的生长，而另一些模型则认为光和营养成分共同起作用。关于光和养分如何控制浮游植物生长的这两个不同的假设可以产生有关该过程速度和浮游植物血统的预测。研究人员将使用一系列实验室实验来确定养分和灯光对浮游植物生长的影响是最好的建模，因为这两个限制资源是独立或共同起作用的。该实验将有助于改善全球海洋中实施的海洋生态系统模型，但在北极特别相关，在北极，由于人为气候变化，光和营养的可用性都在迅速变化。在化学固醇中，各个培养物将保持在恒定的温度，光和营养条件下。使用五个光和五个NO3条件进行的25种独特的相互作用NO3和光线限制的治疗组合，以及在光饱和但NO3-过渡物条件下进行五种其他处理。在适应培养物对治疗方法之后，研究人员将测量浮游植物生物量和光合作用与辐照度（P-E）关系（P-E）关系，以及浮游植物的增长率将从培养基稀释率中确定。然后将计算每种处理的光和营养限制项。最后，最能描述共同限制光和营养条件之间关系的最佳功能关系将通过将两种已建立的（最小和乘法）关系与限制项之间的各种非线性关系进行比较，这反映了NSF的法定任务，并通过基金会的知识优点和广泛的影响来通过评估来诚实地通过评估来进行评估，以诚实地进行评估。