Trait heterogeneity effects on trophic interactions: the role of essential nutrients

食物质量取决于食物中必需资源的可获得性，并对捕食者的生理、行为和生活史特征有很大影响。该项目的目标是将这种食品质量影响纳入最近的性状变异方法。我们将评估食物质量和相关的反馈机制在塑造性状异质性和捕食者和猎物之间的复杂和动态的相互作用的作用。特别是，我们要估计种群动态和物种共存的研究种间性状的变化，在二养模型系统和intraguild捕食在三养模型系统。使用相结合的实验和理论的方法，我们正在研究简单，手动组装，因此高度听话的食物网在恒化器系统组成的轮虫捕食者和两个猎物物种的食物质量（基本脂质方面）有很大的不同。我们假设，生物化学营养物质的限制将主要影响捕食者的猎物利用效率（从而其数值响应和增长率），但不能拯救猎物的捕食，因为这是低适口性的情况下。由于低质量猎物的利用取决于高质量猎物的可用性和捕食者的生理反应，营养相互作用和种群密度可以是高度动态的，导致营养水平之间的重要反馈回路。随后，将探讨更高的复杂性的食物网，考虑到，例如，在被捕食物种之间的防御能力的潜在差异和额外的中间食草动物（内公会捕食）的存在。种群/群落动态将通过迭代使用数学模型和实验进行研究。了解必需营养素在塑造种群动态方面的潜力对于预测种群和食物网如何应对不断变化的环境条件至关重要。

Food quality depends on the availability of essential resources in the prey and has great impacts on physiological, behavioral and life history traits of predators. The objective of the project is to integrate such food quality effects into recent approaches on trait variation. We will assess the role of food quality and associated feedback mechanisms in shaping trait heterogeneity and the complex and dynamic interactions between predator and prey. In particular, we want to estimate population dynamics and species coexistence by studying interspecific trait variation in bi-trophic model systems and intraguild predation in tri-trophic model systems. Using a combined experimental and theoretical approach, we are studying simple, manually assembled and therefore highly tractable food webs in chemostat systems consisting of a rotifer predator and two prey species substantially differing in food quality (in terms of essential lipids). We assume that a limitation by biochemical nutrients will mainly affect the prey utilization efficiency of the predator (and thus its numerical response and growth rate), but not saving the prey from predation as this is the case for low palatability. As the utilization of the low quality prey depends on the availability of the high quality prey and the physiological response of the predator, trophic interactions and population densities can be highly dynamic, resulting in important feedback loops between trophic levels. Subsequently, food webs of higher complexity will be explored, considering, for instance, potential differences in defense capacities among prey species and the presence of additional intermediary grazers (intra-guild predation). The population/community dynamics will be investigated by iteratively using mathematical models and experiments. Understanding the potential of essential nutrients in shaping population dynamics is crucial for predicting how populations and food webs will respond to changing environmental conditions.