QEIB: Extended multitrophic diversity maintenance theory

几个世纪以来，生态学家一直无法理解维持自然群落生物多样性的力量。迄今为止取得的大部分进展都来自于理论的发展，这些理论提供了可以通过实验或观测进行检验的具体预测。该项目将以新的、重要的、尽管具有挑战性的方式扩展现有的生物多样性理论。研究人员将对两种基本的生态相互作用--竞争和捕食--如何以及何时相互作用影响物种多样性进行理论预测。这些预测将推动基础生态研究以及保护和管理工作，以保护生物多样性，以应对物种入侵和越来越多的人为干扰。该项目将在量化理论开发和建模方面提供强有力的培训，进一步增强我们预测未来对生物多样性挑战的影响的能力。目前的多样性理论认为，竞争和捕食的影响通常是相互抵消的，预测在两者都存在的情况下，共存比只有一种机制存在时更弱。什么时候在群落中增加捕食者会使共存变得更有可能，以及用一个捕食者取代另一个捕食者会如何影响他们对群落多样性的影响？研究人员将从一个可以是线性的或非线性的模型开始，允许分离不同相互作用的影响(营养水平内的竞争，来自较高和较低水平的影响)，并了解非线性如何影响这些过程的结合方式。他们将研究生物因素中非线性的根源，如生活史、特征和行为。他们还将研究食物网的结构，以预测复杂食物网中的许多间接相互作用如何改变基于捕食和基于竞争的机制的相对优势和联合作用。将开发模型来预测物种灭绝对食物网和群落其他成员的影响。最后，将开发模型来研究营养级联以及基于竞争和基于捕食的共存机制的作用如何受到营养位置和关键物种的时空动态之间的关系的影响。由此产生的扩展理论的价值将对基础生态学和旨在保护生物多样性的各种应用具有相当大的价值。通过与高中教师合作，将研究生和博士后研究人员的量化培训扩展到中学教育。发展这些联系以加强生物数学的前景是新颖的，可能会加强生态学和生物学的几个领域。

Understanding the forces that maintain biodiversity in natural communities has eluded ecologists for centuries. Much of the progress made to date has come from development of theory that provides specific predictions that can be tested experimentally or observationally. This project will extend existing biodiversity theory in new and important, though challenging, ways. The investigator will develop theoretical predictions for how and when two fundamental ecological interactions - competition and predation - interact to influence species diversity. These predictions will advance basic ecological research as well as conservation and management efforts to preserve biodiversity in the face of species invasion and increasing anthropogenic disturbance. The project will provide strong training in quantitative theory development and modeling, further enhancing our ability to predict the effects of future challenges to biodiversity. Current diversity theory suggests that the effects of competition and predation commonly counteract one another, predicting that coexistence is weaker in the presence of both than when only one of these mechanisms is present. When will adding a predator to a community make coexistence more likely, and how will substituting one predator for another affect their influence on community diversity? The investigators will begin with a model that can be linear or nonlinear, allowing the effects of different interactions (competition within a trophic level, effects from higher and lower levels) to be separated and to understand how nonlinearities affect the ways in which these processes combine. They will examine the roots of nonlinearities in biological factors such as life-history traits and behavior. They will also examine food web structure to predict how the numerous indirect interactions in complex food webs alter the relative strengths and joint action of predation-based and competition-based mechanisms. Models will be developed to predict the consequences of species extinctions on other members of food webs and communities. Finally, models will be developed to examine how trophic cascades and the roles of competition-based and predation-based coexistence mechanisms are affected by the relationship between trophic position and the spatial and temporal dynamics of key species. The value of the resulting extended theory will have considerable value to basic ecology and to diverse applications aimed at preserving biodiversity. Quantitative training of graduate students and postdoctoral researchers will be extended to secondary education through collaboration with high school teachers. The prospect of developing these ties to strengthen biomathematics is novel, and may strengthen several areas of ecology and biology.