Freshwater metacommunities: dispersal through space and time at multiple scales

是什么决定了社区的结构和动态？这个基本而古老的问题在今天仍然非常相关，构成了我研究计划的基础。到目前为止，我的工作已经清楚地表明，通过元社区概念将当地环境和空间分散过程整合到社区结构的调节中，对于捕捉构建当地社区的所有重要过程是绝对必要的。这项研究为最近发展的元群落框架提供了一些明确的观测证据，该框架研究通过分散物种相互联系的地点。然而，另外两个重要的生态决定因素，时间过程和物种特征，目前仅隐含在集合群落理论中。明确地将它们纳入元社区框架将是确定本地、空间和时间元社区动态的根本原因的重要一步，这是我的研究计划的长期目标。我将使用水文动态的和平-阿萨巴斯卡三角洲的枝角群落作为检验特定假设的模型系统。在接下来的5年里，我将重点放在：1)一个季节内短期时间元群落动态的模式和原因；2)季节之间中期时间元群落动态的模式和原因；以及3)个体物种特征如何最终导致这些元群落动态。前两个项目为两个完整的博士项目，第三个项目为一系列硕士和本科生研究项目。这些项目结合了观察和实验方法，以及现代分子技术和最先进的统计分析。这些新颖的研究问题和结果将包括重要的时间过程和物种特征，从而扩展元群落理论的机制基础。此外，它还将为预测和平-阿萨巴斯卡三角洲因气候变化而造成的压力和恢复期间的生态系统反应提供严格的科学基础。

What determines community structure and dynamics? This basic and ages-old question is still very relevant today and forms the basis of my research program. My work to date has clearly illustrated that integrating local environmental and spatial dispersal processes in the regulation of community structure through the metacommunity concept is absolutely necessary to capture all the important processes structuring local communities. This research provided some clear observational evidence for the recently developed metacommunity frame work that studies sites interconnected to each other through dispersing species. However, two other important ecological determinants, temporal processes and species traits, are currently only implicitly included in metacommunity theory. Explicitly incorporating them in the metacommunity framework will be an important step in determining the fundamental causes for local, spatial, and temporal metacommunity dynamics, the long term objectives of my research program. I will employ cladoceran communities in the hydrologically dynamic Peace-Athabasca Delta as a model system for testing specific hypotheses. I will focus for the next 5 years on: 1) the patterns and causes of short term temporal metacommunity dynamics within a season; 2) the patterns and causes of medium temporal metacommunity dynamics between seasons; and 3) how individual species traits ultimately cause these metacommunity dynamics. The first two projects are structured as two complete PhD projects, the third project as a series of Master and Undergraduate research projects. These projects use a combination of observational and experimental approaches, together with modern molecular techniques and state-of-the-art statistical analyses. These novel research questions and results will expand the mechanistic basis of metacommunity theory by including the important temporal processes and species traits. In addition, it will provide the rigorous scientific basis for predicting ecosystem responses during stresses and recovery because of climate change in the Peace-Athabasca Delta.