Ecoevolutionary feedbacks of phenotypic plasticity and mono- vs polyclonal communities in bi- and tritrophic systems

我们的项目将集中在个体性状变异（表型可塑性）和遗传性状变异（多克隆系统）的影响，人口，社区和性状动态的双和三营养系统与藻类为食物，草食性纤毛虫作为主要消费者和他们的纤毛虫捕食者。在我们的系统中，表型可塑性作用于两个营养水平。纤毛虫（Euplotes aediculatus和E. Carinatus）可以形成针对其捕食者的表型塑料防御，其中包括防御和竞争力之间的权衡。此外，我们将使用不同的游仆虫菌株，在单克隆和多克隆实验中的可塑性，生长速率和竞争力的反应规范不同。因此，我们研究性状变异通过可塑性和通过在克隆组成的变化。此外，我们将使用可以形成诱导型犯罪的捕食者（Lembadion bullinum），这部分地允许克服猎物防御，或捕食者，这不会对猎物防御做出反应（Stenostomum bagnetorum）。通过我们的系统，我们将解决以下假设：1。 在消费者水平上，不同克隆中以克隆特异性反应规范（表型可塑性）表达的性状变异促进了三营养系统内营养水平的稳定性和持久性。2. 与单克隆系统相比，多克隆消费者系统具有克隆特异性的性状反应规范，增加了群体稳定性. 在一个三营养系统中，消费者营养级上的性状变异可能比两个营养级（消费者和顶级捕食者）上的性状变异更稳定营养动态，这取决于调整的相对速度。它与SPP中的其他项目密切相关，但它的独特之处在于我们研究了一个三营养系统，在该系统中，捕食者形成诱导进攻，以应对其猎物的诱导防御。我们的项目将促进一般生态过程的理解，特别是捕食者-猎物和食物网动态。

Our project will focus on the effects of individual trait variation (phenotypic plasticity) and genetic trait variation (polyclonal systems) on population, community and trait dynamics in bi- and tri-trophic systems with algae as food, herbivorous ciliates as primary consumer and their ciliate predators. In our system phenotypic plasticity acts on two trophic levels. The ciliates (Euplotes aediculatus and E. octocarinatus) can form phenotypically plastic defences against their predators, which includes a trade-off between defence and competitive strength. Furthermore, we will use different Euplotes strains that differ in their reaction norms of plasticity, growth rates and competitive strength in mono- and polyclonal experiments. Consequently, we study trait variation via plasticity and via shifts in the clonal composition. Additionally, we will use predators that can form inducible offences (Lembadion bullinum), which partly allow to overcome the prey defences, or predators, which do not respond to the prey defences (Stenostomum sphagnetorum). With our system we will address the following hypotheses:1. Trait variation expressed in clone-specific reaction norms (phenotypic plasticity) in different clones on the consumer level promotes the stability and persistence of trophic levels within a tri-trophic system. 2. Polyclonal consumer systems with clone-specific reaction norms of traits increase population stability compared to monoclonal systems.3. Trait variation on the consumer trophic level may stabilize trophic dynamics more than trait variation on two trophic levels (consumer and top predator) within a tri-trophic system depending on the relative speeds of adjustment.Our project will combine empirical experiments and mathematical modelling approaches. It is closely linked to other projects in the SPP but is unique in that we study a tri-trophic system where the predator forms inducible offenses in response to its prey’s inducible defences. Our project will foster the understanding of ecological processes in general and of predator-prey and food web dynamics in particular.