Linking resource competition and biodiversity in meta-ecosystems

资源竞争是生态学中最基本的物种相互作用之一。在过去的十年里，它被作为生物群落结构和物种丰富的主要驱动力而得到了深入的研究。最近，人们越来越认识到，空间结构的群落不仅通过生物体的扩散联系在一起，而且通过物质和资源的流动而联系在一起。然而，尽管这种元生态系统是群落生态学中的一个新兴主题，但对物种可能改变资源分布的空间结构环境中的竞争知之甚少。在拟议的研究项目中，我们的目标是从机械上理解元生态系统中资源竞争、生物多样性和生态系统功能之间的关系。为了解决这个问题，我们将开发一个框架来描述元生态系统中的资源竞争。我们将元生态系统建模为一个由扩散连接的斑块组成的系统，这些斑块在资源的水平和比例上存在差异。这种方法使我们能够研究空间资源分布对生态系统功能的影响。特别是，我们将(1)确定在空间结构环境中增强竞争能力的物种特征；(2)量化单个物种如何塑造其空间资源环境；(3)调查元生态系统中的两个物种和多个物种竞争，以及使生物多样性最大化的条件；(4)分析资源和生物量分布之间的反馈及其对资源使用、生产力和生物多样性的影响；(5)探索斑块元生态系统中资源利用、初级生产和生物多样性格局之间的关系。最后，我们有独特的机会用浮游生物群落来验证我们的理论预测，在一个由串联连接的血管组成的类似恒化器的系统中，两种基本营养物质从系统的相反端供应(所谓的gradostat)。我们的方法将能够在系统和斑块水平上评估多样性和生产力，并接受理论研究，产生一种新的、高分辨率的元生态系统过程分析。这一研究项目的结果将有助于弥合经典竞争理论和空间结构的元生态系统之间的差距，并将对加强我们对野外群落中物种共存和生物多样性-功能关系的理解具有普遍意义。

Resource competition is one of the most fundamental species interactions in ecology. It has been studied intensely in the last decade as a major driver for the structure and species richness of biological communities. Recently, it is increasingly acknowledged that spatially structured communities are not only connected by dispersal of organisms but also by flows of matter and resources. However, despite the fact that such meta-ecosystems are an emerging topic in community ecology, not much is known about competition in spatially structured environments where species may modify resource distributions. In the proposed research project we aim to gain a mechanistic understanding about the relationship between resource competition, biodiversity and ecosystem functioning in meta-ecosystems. To address this question we will develop a framework for describing resource competition in meta-ecosystems. We will model a meta-ecosystem as a system of diffusively connected patches that differ in the levels and ratios of resources. This approach enables us to study the effects of spatial resource distributions on the eco-system functioning. In particular, we will (i) determine species traits that enhance competitive abilities in a spatially structured environment, (ii) quantify how a single species shapes its spatial resource environment, (iii) investigate two-species and multi-species competition in a meta-ecosystem, as well as conditions that maximize biodiversity, (iv) analyse feedbacks between resource and biomass distributions, and their influence on the resource-use, productivity and biodiversity, and (v) explore the relationship between resource-use, primary production and biodiversity patterns in patchy meta-ecosystems. Finally, we have the unique opportunity to validate our theoretical predictions against experiments with plankton communities in a chemostat-like system consisting of serially connected vessels where two essential nutrients are supplied from opposing ends of the system (so-called gradostat). Our approach will enable to assess the diversity and productivity both at the system and the patch level and admits theoretical investigations, yielding a novel, high-resolution analysis of meta-ecosystem processes. The results of this research project will help to bridge the gap between classic competition theory and spatially structured meta-ecosystems and will be of general relevance for enhancing our understanding of species coexistence and biodiversity-functioning relationships in field communities.