Disentangling demographic co-effects of predation and pollution on population dynamics

In nature species react to a variety of endogenous and exogenous ecological factors. Understanding the mechanisms by which these factors interact and drive population dynamics is a need for understanding and managing ecosystems. In this study we assess, using laboratory experiments, the effects that the combinations of two exogenous factors exert on the endogenous structure of the population dynamics of a size-structured population of Daphnia. One exogenous factor was size-selective predation, which was applied on experimental populations through simulating: (a) selective predation on small prey, (b) selective predation on large prey and (c) non-selective predation. The second exogenous factor was pesticide exposure, applied experimentally in a quasi-continuous regime. Our analysis combined theoretical models and statistical testing of experimental data for analyzing how the density dependence structure of the population dynamics was shifted by the different exogenous factors. Our resul...

自然界中，物种会对多种内源性和外源性生态因子做出反应。理解这些因子相互作用并驱动种群动态的机制，是理解和管理生态系统的必要前提。本研究通过实验室实验，评估了两种外源性因子组合对体型结构化水蚤（Daphnia）种群动态内源性结构的影响。其中一种外源性因子为体型选择性捕食，通过模拟以下三种方式施加于实验种群：（a）选择性捕食小型猎物；（b）选择性捕食大型猎物；（c）非选择性捕食。第二种外源性因子为农药暴露，实验中采用准连续模式施加。我们的分析结合了理论模型与实验数据的统计检验，旨在探究不同外源性因子如何改变种群动态的密度依赖结构。我们的结果...