QEIB: Theory for communities in nonstationary environments

尽管自然界几乎总是在不断变化，生态学理论在很大程度上是利用数学模型发展起来的，这些模型假设生态系统会达到稳定的平衡。近几十年来，这种模式已被物理环境随时间和空间变化的模式所补充和部分取代。然而，这些模型环境总是具有平稳性，这意味着它们可以用一组固定的统计数据来表征，例如发生波动的平均值，以及波动的幅度和性质的度量。尽管我们已经从这些模型中学到了很多东西，但现在很清楚，在自然界中，平稳性的假设并不成立，因为环境随着时间的推移是不稳定的。人为气候变化的挑战意味着对自然环境更现实的非平稳假设对未来至关重要，但它们也需要更准确地理解过去和现在的生态。本研究将建立受非平稳环境影响的相互作用物种模型，以预测非平稳对生物多样性维持的影响。该项目将开发数学工具，用于对多样性维持进行生态预测，使固定预测能够被取代或修改，以适应更现实的非固定条件。这将有助于表明，与以前的平稳假设相比，在非平稳情况下，物种和环境的哪些方面对多样性的维持有很大的影响。该项目还将研究不同物种因应环境变化而以不同速度迁徙，如何影响物种间相互作用的结果和维持生物多样性。研究结果将应用于自然环境的保护和管理，并帮助社会面对全球环境变化的挑战，而非平稳理论是必不可少的。此外，将有一个主要的教育和培训组成部分，为学生和博士后研究人员提供非平稳环境中生态模型的新工具。高中教师也将接受关于环境变化的生态模型的培训，以促进课堂教学材料的发展。

Although the natural world is almost always in flux, ecological theory has been largely developed using mathematical models that assume that ecosystems come to a stable equilibrium. In recent decades, such models have been supplemented and partially replaced by models in which the physical environment varies in time and space. However, those model environments have invariably had the property of stationarity, which means that they can be characterized by a fixed set of statistics, such as averages, about which fluctuations occur, and measures of the magnitude and nature of the fluctuations. Although much has been learned from these models, it is now clear that the assumption of stationarity does not hold in nature, because environments are not stable over time. The challenge of anthropogenic climate change means that more realistic nonstationary assumptions about the physical environment are essential for the future, but they are also needed for more accurate understanding of past and present ecology. This research will develop models of interacting species subject to nonstationary environments to predict the impact of nonstationarity on the maintenance of biological diversity. The project will develop mathematical tools for making ecological predictions about diversity maintenance that allow stationary predictions to be replaced or modified for more realistic, nonstationary conditions. This will help show which aspects of species and of the environment have large effects on the maintenance of diversity in the nonstationary case as compared with the previous stationary assumptions. The project will also study how migration of different species at different rates in response to a changing environment affects the outcomes of the interactions between species and the maintenance of biological diversity. The results of the research will have application to the conservation and management of natural environments, and help society face the challenges of global environmental change, for which nonstationary theory is essential. In addition, there will be a major education and training component for students and postdoctoral fellows in new tools for ecological models in nonstationary environments. High school teachers also will be given training in ecological models for changing environments to foster the development of materials for classroom instruction.