Forecasting species vulnerability to global change

对生态系统进行预测的一个主要限制在于解决通常研究机械过程的小尺度与与种群动态、物种状态和生态系统过程有关的大时空尺度之间的不连续性。我的研究项目集中在这些理论和应用挑战的交叉点上。我利用跨尺度和生物组织水平的调查来提高对机制的理解，这些机制支持预测何时何地不同的环境压力源对物种和生态系统的持久性很重要。为此，我的建议解决了两个基本问题，即从个体种群动态到生态系统恢复力预测的全球变化的原因和后果。尽管经过了四十年的实验和理论研究，我们对为什么有些两栖动物数量下降而有些两栖动物数量没有下降的理解仍然处于初级阶段。通过更好地整合这些广泛的数据和理论，我们能否在衰退之前改进对脆弱性的预测？本项目将比较生活史和种群动力学理论与实验和建模相结合，以评估两栖动物种群动态的预测模式。2)历史和当前的压力因素是否会使即使是保护最好的生态系统也容易发生非线性变化和生物多样性丧失？该项目将评估外来鳟鱼的广泛引入是否会使山地两栖动物及其栖息的独特生态系统在气候引起的干旱下发生灾难性变化。我将结合现有种群数据的元分析、矩阵模型模拟（结合压力源和不同形式的内在种群调节）、测试机制预测的实地实验、景观尺度的GIS建模和对一组两栖动物未来脆弱性的预测来解决这些问题。该研究项目还将为研究生和本科生提供野外生态学和前沿定量方法方面的重要培训，并为加拿大实现保护生物多样性的国际目标做出贡献。

A central limitation to making predictions about ecological systems lies in resolving the discontinuity between the small scales at which mechanistic processes are usually studied and the broad spatial and temporal scales relevant to population dynamics, species status, and ecosystem processes. My research program is focused at the intersection of these theoretical and applied challenges. I draw on investigations across scales and levels of biological organization to improve understanding of mechanisms that underpin predictions of when and where different environmental stressors will be important for the persistence of species and ecosystems. To this end, my proposal addresses two fundamental questions of the causes and consequences of global change at scales spanning individual population dynamics to predictions of ecosystem resilience. 1) In spite of four decades of experiments and theory, our understanding of why some amphibian populations decline and others do not is still in its infancy. Can we improve predictions of vulnerability prior to declines by better integrating this extensive data and theory? This project will link comparative life history and population dynamics theory with experiments and modeling to evaluate predictive patterns in amphibian species population dynamics. 2) Do combinations of historic and current stressors predispose even the best-protected ecosystems to non-linear shifts and biodiversity loss? This project will evaluate whether the widespread introduction of exotic trout predispose montane amphibians and the unique ecosystems they inhabit to catastrophic shifts under climate-induced desiccation. I will address these questions through a combination of meta-analyses of existing population data, matrix model simulations (incorporating stressors and different forms of intrinsic population regulation), field experiments testing mechanistic predictions, and landscape-scale GIS modeling and projections of future vulnerability for a suite of amphibians. This research program will also provide significant training for graduate and undergraduate students in field ecology and cutting-edge quantitative methods, and contribute to Canada's intellectual capacity to meet international targets for preserving biodiversity.