QEIB: Island Biogeography and Metacommunity Dynamics of Food Webs--Theory and Experiments in a Model System

生态群落是由生物组成的，随着时间的推移，这些生物从周围地区定居到当地，并通过随后的物种相互作用来决定物种的命运。这种殖民化的顺序和随后的群落组成变化被称为“群落聚集”。由于生态群落不是静态的，因此了解群落的组成对成功保护生物多样性至关重要。与以前的工作不同，本项目研究斑块景观中的组装，其中斑块内组装和斑块之间的运动都很重要。它使用最近开发的数学方法和由微观世界中的原生动物组成的高度易于处理的实验室系统来了解物种组成的转变。这些方法是开发和测试生态理念的有力工具，然后可以在我们希望保护的现场系统中进行测试。该方法包括通过实验确定所有持久的物种组合，并确定以前缺失的物种入侵的频率。实验将测试斑块间移动对物种组成频率分布的影响，物种是本地的还是非本地的，以及物种在景观中移动的距离。对这种转换进行建模将产生一个精确的、可测试的、通用的理论框架，可以应用于研究许多系统中的社区组装。解决的问题是保护生物多样性，管理入侵物种和栖息地恢复的关键。

Ecological communities are comprised of organisms that assemble over time by the colonization of a local site from the surrounding region and by subsequent species interactions that determine the fate of species. The sequence of such colonizations and subsequent changes in community composition are termed "community assembly". Because ecological communities are not static, understanding assembly is central to successfully conserving biodiversity. Unlike previous work, this project studies assembly in patchy landscapes where both within-patch assembly and between-patch movement are expected to be important. It uses a recently-developed mathematical approach and a highly-tractable laboratory system consisting of protozoa in microcosms to understand transitions in species composition. These approaches represent powerful tools for developing and testing ecological ideas that can then be tested in the field systems we wish to conserve. The approach consists of experimentally identifying all persistent species combinations and determining the frequency of invasion by previously absent species. Experiments will test the effect on the frequency distribution of species compositions of between patch movement, whether species are native or nonnative, and the distance over which species are moving in landscapes. Modeling such transitions will produce a precise, testable, general theoretical framework that can be applied to studying community assembly in many systems. The problems addressed are key to conservation of biodiversity, management of invasive species, and habitat restoration.