Robust Theoretical Frameworks for Ecological Dynamics Subject to Stoichiometric Constraints

受化学计量约束的生态动力学的稳健理论框架

• 批准号: 0920744
• 负责人: Yang Kuang
• 金额: $ 49.89万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-15 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0920744&HistoricalAwards=false
• 关键词: Robust; Theoretical; Frameworks; Ecological; Dynamics

Organisms are composed of chemical elements such as carbon, hydrogen, oxygen, nitrogen, and phosphorus. Research in the area known as ecological stoichiometry (ES) has highlighted the ecological importance of the relative abundance of chemical constituents, known to vary considerably among species and across trophic levels. ES deals with how the balance of energy and elements affect and are affected by organisms and their interactions in ecosystems. It has proven to be an important new lens through which to view and understand ecological interactions and has gained momentum by explicitly linking the elemental physiology of organisms to their food web interactions and ecosystem function. Thus, ES theory covers multiple biological scales and allows, via rigid physical and chemical constraints, the construction of robust mechanistic and predictive mathematical models. While biology has a research tradition that is empirical in nature and often only weakly connected to formal quantitative analyses, mathematical and theoretical biology on the other hand has had a research agenda that has often been somewhat distanced from mainstream empirical biology. There is not enough effort and attention on marrying empirical results with theoretical findings. The investigators will extend and generalize existing well-received stoichiometry-based mathematical models to encompass a broader range of ecological situations, including cell quota dynamics, consumer age- or size-structures, variable consumer stoichiometry, and delayed nutrient cycling. Once such a generalized theoretical framework is established, the investigators will construct and evaluate models inspired by recent empirical discoveries in ES, including one considering the effects on consumer dynamics of not only insufficient food nutrient content but also of excess food nutrient content, and another considering the effects of stoichiometric dietary mixing. Finally, the investigators will challenge these parameterized stoichiometric models against observed population growth dynamics qualitatively and quantitatively. In doing so, the investigators hope to achieve a far-reaching synthesis between model and experiment in the form of new theoretical applications that may allow for direct and quantitative predictions of the effects of stoichiometric constraints on ecosystem processes. The models the investigators will investigate may motivate challenging but tractable problems in areas of qualitative and computational studies of nonlinear differential equations and delay differential equations. This project will have a broad impact in both local and global environs. The biological findings of this project may have a number of practical applications to issues such as eutrophication, biofuel production, global change, and biodiversity. Its theoretical outcomes will provide a solid and user-friendly framework to build mathematical models that allow quantitative prediction of ecological interactions. Moreover, it will find many ready applications in cancer and other within host diseases dynamics and treatment modeling since one can view cancer cells and pathogens as invading species in a host ecosystem. The investigators' collaborative efforts will provide undergraduate and graduate students of diverse ethnic/racial backgrounds with first-hand educational experience in cross-disciplinary communication and exploration. Finally, the investigators are partnering with Arizona State University's School of Life Sciences award-winning Ask-A-Biologist program to develop articles and virtual experiments related to this project to enhance middle- and high school student learning of biological and mathematical concepts.

有机体是由碳、氢、氧、氮和磷等化学元素组成的。生态化学计量学领域的研究突出了化学成分相对丰度的生态重要性，已知化学成分在物种和营养级之间差异很大。生态系统学涉及能量和元素的平衡如何影响生物体及其在生态系统中的相互作用。它已被证明是一个重要的新的透镜，通过它来观察和理解生态相互作用，并已获得势头，明确联系的生物体的基本生理学，其食物网的相互作用和生态系统的功能。因此，ES理论涵盖了多个生物尺度，并允许通过严格的物理和化学约束，构建强大的机制和预测的数学模型。虽然生物学有一个研究传统，在本质上是经验的，往往只有弱连接到正式的定量分析，数学和理论生物学在另一方面有一个研究议程，往往有点远离主流经验生物学。在将实证结果与理论发现相结合方面，还没有足够的努力和重视。研究人员将扩展和推广现有的基于化学计量的数学模型，以涵盖更广泛的生态情况，包括细胞配额动态，消费者年龄或大小结构，可变消费者化学计量和延迟营养循环。一旦建立了这样一个广义的理论框架，研究人员将构建和评估模型的启发，最近的经验发现在ES，包括一个考虑消费者动态的影响，不仅不足的食物营养成分，但也过量的食物营养成分，另一个考虑化学计量的饮食混合的影响。最后，研究人员将挑战这些参数化的化学计量模型对观察到的人口增长动力学定性和定量。在这样做的过程中，研究人员希望以新的理论应用的形式实现模型和实验之间的深远综合，从而可以直接和定量预测化学计量约束对生态系统过程的影响。研究人员将调查的模型可能会激发非线性微分方程和延迟微分方程的定性和计算研究领域中具有挑战性但易于处理的问题。该项目将在当地和全球范围内产生广泛影响。该项目的生物学研究结果可能对富营养化、生物燃料生产、全球变化和生物多样性等问题有许多实际应用。其理论成果将提供一个坚实和用户友好的框架，以建立数学模型，允许定量预测生态相互作用。此外，它将在癌症和其他宿主疾病动力学和治疗建模中找到许多现成的应用，因为人们可以将癌细胞和病原体视为宿主生态系统中的入侵物种。研究人员的合作努力将为不同民族/种族背景的本科生和研究生提供跨学科交流和探索的第一手教育经验。最后，研究人员正在与亚利桑那州立大学生命科学学院获奖的Ask-A-Biologist项目合作，开发与该项目相关的文章和虚拟实验，以提高初中和高中学生对生物和数学概念的学习。