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浮游特征多样性如何影响湖泊生态系统功能的稳定性。后者受组成种群间的协变程度的影响，这可能与浮游生物种群间生态特征的功能相似性有关。特别是，我们的目标是了解竞争、非生物强迫和放牧如何影响物种协变和它们的功能相似性之间的关系。在分析了这方面的浮游植物观测数据后，我们希望使用一个包括不同捕食者和猎物群落之间相互作用的适当动态模型来扩展我们的概念性理解。我们将对控制竞争、非生物环境强迫和放牧的相对强度的模型参数进行因子处理，以产生关于功能相似性与浮游植物形态类型之间以及不同浮游动物(纤毛虫、轮虫、枝角类、桡足类)之间的协变之间关系的见解和新的假设。后者在可能影响功能相似性和动态相似性之间关系的因素方面有所不同，如放牧选择性、代谢速率和对非生物强迫的敏感性。在接下来的步骤中，这些概念性的见解将与长期的湖泊数据集相关。

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.