An adaptive food web model for the epipelagic and mesopelagic

上层和中层的自适应食物网模型

• 批准号: 0424860
• 负责人: Edward Laws
• 金额: $ 31.26万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-08-15 至 2006-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0424860&HistoricalAwards=false
• 关键词: adaptive; food; web; model; epipelagic

This is a continuation of modeling and synthesis efforts to understand carbon cycling by the ocean biota. The intellectual merit of the project lies in the development of a microbial food web model in which otherwise unconstrained parameter values are chosen to produce a steady state having a specified degree of resiliency, meaning that the system returns to equilibrium following a small perturbation with a characteristic time constant less than a specified value. This is a very different approach from most modeling exercises in which parameter values are chosen by least squares to give the best possible fit to field data. In the prior study, it was assumed that the system settled down into a steady state with maximum resiliency, meaning that the return to equilibrium was more rapid than any other steady state. Further consideration has indicated, however, that the interesting characteristics of the system (e.g., export ratio, composition in terms of functional groups) are well constrained without requiring that the system be in the absolutely most resilient state. If the time constant associated with return to equilibrium is less than 10-20 days, system characteristics are sharply defined. Using the new stability criterion, modifications to the existing model will be explored as follows: (1) possible simplification of the food web model to facilitate its incorporation into a physical circulation model, (2) development of a light-limited version of the model, (3) development of an analogous model to describe microbial processes within the mesopelagic, and (4) use of the mesopelagic model to explore the importance of horizontal advection and diffusion processes in the remineralization of organic matter and consumption of oxygen. The broader impacts of the proposed work include (1) the training of a graduate student, (2) incorporation of results of the work into a graduate course taught by the principal investigator (Mathematical Methods for Oceanographers), and (3) incorporation of concepts and lessons learned from the work into curricula targeting undergraduate minorities at the University of Hawaii. The third impact reflects the role of the principal investigator on a grant entitled "Hawaii Kumu-Ola: Source of Knowledge Program", which is funded by the NSF Division of Human Resources Development Tribal Colleges and Universities program. That grant is intended to draw students from minority groups, particularly those of Hawaiian and Pacific Island ancestry, into careers in science, technology, engineering, and mathematics (STEM). One of the keys to drawing minorities into STEM and to retaining them once they enroll is make the material culturally relevant. The application of simple mathematical principles to marine food webs and to fisheries management is a great way to interest these students in mathematics. The PI's continued work on the Kumu-Ola project will allow him to integrate the results of this research into culturally relevant curricula for minority students in Hawaii.

这是为了理解海洋生物群的碳循环而进行的建模和合成工作的延续。该项目的智力价值在于开发了一种微生物食物网模型，在该模型中，选择不受约束的参数值来产生具有特定程度弹性的稳定状态，这意味着系统在特征时间常数小于指定值的小扰动后恢复平衡。这是一种与大多数建模练习非常不同的方法，在大多数建模练习中，参数值是通过最小二乘来选择的，以提供与现场数据的最佳拟合。在之前的研究中，假设系统稳定在一个具有最大弹性的稳态，这意味着恢复平衡比任何其他稳态都要快。然而，进一步的考虑表明，该系统的有趣特征（例如，出口比率，官能团的组成）得到了很好的约束，而无需系统处于绝对最具弹性的状态。如果与恢复平衡相关的时间常数小于10-20天，则系统特征被明确定义。利用新的稳定性判据，将对现有模型进行如下修改：(1)可能对食物网模型进行简化，以便将其纳入物理循环模型；(2)开发该模型的轻型限制版本；(3)开发一个类似的模型来描述介层内的微生物过程；(4)使用介层模型来探索水平平流和扩散过程在有机物再矿化和氧气消耗中的重要性。拟议工作的更广泛影响包括：(1)研究生的培训，(2)将工作结果纳入首席研究员教授的研究生课程（海洋学家的数学方法），以及(3)将从工作中获得的概念和经验教训纳入夏威夷大学针对本科少数民族的课程。第三个影响反映了主要研究者在一项名为“夏威夷Kumu-Ola：知识来源项目”的资助中所扮演的角色，该项目由美国国家科学基金会人力资源开发部部落学院和大学项目资助。这项资助旨在吸引少数族裔学生，特别是夏威夷和太平洋岛屿血统的学生，从事科学、技术、工程和数学（STEM）领域的职业。吸引少数族裔进入STEM并在他们入学后留住他们的关键之一是使材料具有文化相关性。将简单的数学原理应用于海洋食物网和渔业管理，是让这些学生对数学产生兴趣的好方法。PI在Kumu-Ola项目上的持续工作将使他能够将这项研究的结果整合到夏威夷少数民族学生的文化相关课程中。