Influence of bottom-up, top-down and external forces on compensatory dynamics - a model study related to plankton data of Lake Constance

我们的总体目标是了解水生特征多样性如何影响湖泊生态系统功能的稳定性。后者受组成种群之间的协变程度的影响，这可能与浮游生物种群之间生态性状的功能相似性有关。特别是，我们的目标是了解竞争，非生物强迫和放牧影响物种协变和它们的功能相似性之间的关系。在分析了观测浮游植物的数据在这方面，我们要扩大我们的概念理解，使用一个合适的动态模型，包括不同的捕食者和猎物社区之间的相互作用。我们将采用阶乘操纵的模型参数，管理竞争的相对强度，非生物环境强迫和放牧产生的见解和新的假设之间的关系的功能相似性和浮游植物形态型之间的协变和不同群体的浮游动物（纤毛虫，轮虫，枝角类，桡足类）。后者不同的因素可能影响功能和动态相似性之间的关系，如放牧的选择性，代谢率和非生物强迫的敏感性。在稍后的步骤中，这些概念性见解将与长期湖泊数据集相关。

Our overall goal is to understand how planktonic trait diversity influences the stability of lake ecosystem functions. The latter is influenced by the degree of covariation among component populations which may be related to functional similarity of ecological traits between plankton populations. In particular, we aim to understand how competition, abiotic forcing and grazing impact the relationship between species covariation and their functional similarity. After having analyzed observational phytoplankton data in this respect we want to extend our conceptual understanding using a suitable dynamic model comprising the interactions between diverse predator and prey communities. We will employ a factorial manipulation of the model parameters which govern the relative strength of competition, abiotic environmental forcing and grazing to generate insights and new hypotheses about relationships between the functional similarity and the covariation among phytoplankton morphotypes and among various groups of zooplankton (ciliates, rotifers, cladocerans, copepods). The latter differ with respect to factors likely influencing the relationship between functional and dynamic similarity such as grazing selectivity, metabolic rates, and susceptibility to abiotic forcing. In a later step these conceptual insights will be related to long-term lake data sets.