Collaborative Research: Agent-Based Modeling and Observation of Intra-Population Variability in Phytoplankton

合作研究：基于agent的浮游植物种群内变异建模与观测项目目的是研究和评估基于agent的建模（ABM）方法模拟浮游植物营养成分种群内变异的方法。养殖富营养化是由于过量的营养物质输入水体而导致的，是美国和其他国家面临的一个重要环境问题。有效管理水体的营养状态需要精确的生物地球化学（水质、富营养化）模型。目前的模型使用集总系统建模（LSM）方法，该方法假设控制体积内的总体具有平均特性。现代生物地球化学模型将浮游植物的生长描述为内部营养浓度的非线性函数（例如下垂动力学），这种平均假设可能会引入显著的误差。基于主体的建模不假设平均属性，可以模拟种群内营养含量的变化。拟验证的假设是：(1)在实际系统中，营养含量的种群内变异性在浮游植物动态中起重要作用；(2)考虑种群内养分含量变异可提高模型性能；(3)基于agent的模型能够再现观测到的种群内养分含量变化。该模型将在由波士顿查尔斯河的一部分组成的真实系统中进行测试。这项工作的预期效益包括更好地支持对受过度营养投入影响的水生系统作出管理决策。在环境工程研究中，ABM方法尚未被用于探索假设。研究生和本科生将参与研究。来自代表性不足群体的本科生将参与其中。研究结果将通过短期课程、在线资源、会议和期刊论文传播。

Ferdinand L. Hellweger, PINortheastern UniversityCBET-0730239Benjamin S. Twining, PIUniversity of South CarolinaCBET-0730061Collaborative Research: Agent-based Modeling and Observations of Intra-Population Variability in PhytoplanktonThe goal of the project is to investigate and evaluate the agent-based modeling (ABM) approach for simulating intra-population variability in nutrient contents for phytoplankton. Cultural eutrophication, which results from inputs of excess nutrients into water bodies, is an important environmental problem in the US and other countries. The effective management of a water body's trophic state requires an accurate biogeochemical (water quality, eutrophication) model. Present models use a lumped-system modeling (LSM) approach that assumes average properties of a population within a control volume. For modern biogeochemical models that formulate phytoplankton growth as a nonlinear function of the internal nutrient concentration (e.g. Droop kinetics), this averaging assumption can introduce a significant error. Agent-based modeling does not make the assumption of average properties and can simulate intra-population variability in nutrient content. The hypotheses to be tested are (1) intrapopulation variability in nutrient content plays an important role in phytoplankton dynamics in a real system; (2) Accounting for the intra-population variability of nutrient content improves model performance; and (3) Agent-based models can reproduce the observed intra-population variability in nutrient contents. The model will be tested on a real system consisting of a portion of the Charles River in Boston. The expected benefits of the work included improved support for making management decisions for aquatic systems affected by excessive nutrient input. The ABM approach has not been used to explore hypotheses in environmental engineering research. Graduate and undergraduate students will participate in the research. Undergraduate students from under-represented groups will be involved. Dissemination of the results will occur through short courses, on-line resources, conferences, and journal papers.