Effects of spatial subsidies and meta-community dynamics on the relationship between island size and food chain length

食物网特性的空间动态和决定因素是理解生物多样性和生态系统功能的核心。传统上，生态系统的大小是一个连续的空间变量来解释食物链长度的变化。关于陆地系统食物链长度的空间依赖性的知识很少，但水生研究表明，生态系统的大小可能具有很强的影响，但并不总是关键的影响。自然栖息地的开放性导致了物质和生物在生态系统边界和栖息地斑块之间几乎隐含的流动。这些空间补贴和元群落动态代表了不连续的空间变量，它们往往对当地食物网产生最持久的影响。然而，它们对许多食物网属性的影响，如食物链长度，尚未被探索。结合经典的数值群落响应和稳定同位素技术，我们将连续空间（岛屿面积）与空间补贴和元群落动态这两个最突出的非连续空间过程结合起来，探讨它们对节肢动物食物网食物链长度、动态和结构的影响。本研究以湖泊岛屿为研究点，以现代生态学中最基础和公认的空间过程理论——经典岛屿生物地理学为研究基础。现代技术、理想的自然实验条件和合理的理论方法的协同作用将大大促进我们对陆地系统中控制群落和食物网模式的因素的理解。

The spatial dynamics and determinants of food web properties are central to the understanding of biodiversity and ecosystem function. Traditionally ecosystem size, a continuous spatial variable was used to explain variations in food chain length. Knowledge on the spatial dependencies of food chain length in terrestrial systems is scarce, but aquatic studies show that ecosystem size may be of strong, but not always pivotal influence. The openness of natural habitats leads to an almost implicit flux of materials and organisms across ecosystem boundaries and between habitat patches. These spatial subsidies and meta-community dynamics represent discontinuous spatial variables, which often have the most perpetual influences on local food webs. However, their influence on many food web properties, such as food chain length is unexplored. By combining classical numerical community responses and stable isotope techniques, our proposal integrates continuous space (island area) with spatial subsidy and meta-community dynamics, both being the most prominent discontinuous spatial processes, to explore their influence on food chain length, dynamics and structure of arthropod food webs. In using lake islands as study site, we base our research program on classical island biogeography, the most basic and approved theory on spatial processes in modern ecology. The synergy of modern techniques, ideal natural experimental conditions and sound theoretical approaches will significantly advance our understanding of the factors governing community and food web patterns in terrestrial systems.