Abstract:
Predator responses to warming can occur via phenotypic plasticity, evolutionary adaptation or a combination of both, changing their top-down effects on prey communities. However, we lack evidence of how warming-induced evolutionary changes in predators may influence natural food webs. Here, we ask whether wild fish subject to warming across multiple generations differ in their impacts on prey communities compared with their nearby conspecifics experiencing a natural thermal regime. We carried out a common garden mesocosm experiment with larval perch (Perca fluviatilis), originating from a heated or reference coastal environment, feeding on zooplankton communities under a gradient of experimental temperatures. Overall, in the presence of fish of heated origin, zooplankton abundance was higher and did not change with experimental warming, whereas in the presence of fish of unheated origin, it declined with experimental temperature. Responses in zooplankton taxonomic and size composition suggest that larvae of heated origin consume more large-sized taxa as the temperature increases. Our findings show that differences between fish populations, potentially representing adaptation to their long-term thermal environments, can affect the abundance, biomass, size and species composition of their prey communities. This suggests that rapid microevolution in predators to ongoing climate warming might have indirect cross-generational ecological consequences propagating through food webs.
摘要:
捕食者对变暖的反应可以通过表型可塑性发生,进化适应或两者的结合,改变它们对猎物群落的自上而下的影响。然而,我们缺乏气候变暖引起的捕食者进化变化如何影响天然食物网的证据.这里,我们询问,与经历自然热状态的附近物种相比,多代受变暖影响的野生鱼类对猎物群落的影响是否不同。我们用幼虫鲈鱼(Percafluviatilis)进行了普通的花园中观实验,源自加热或参考沿海环境,在实验温度的梯度下,以浮游动物群落为食。总的来说,在加热鱼的存在下,浮游动物的丰度更高,并且没有随着实验变暖而变化,而在存在未加热来源的鱼的情况下,随着实验温度的下降。浮游动物分类学和大小组成的响应表明,随着温度的升高,加热来源的幼虫消耗更多的大型类群。我们的发现表明,鱼类种群之间的差异,可能代表对其长期热环境的适应,会影响丰度,生物量,猎物群落的大小和物种组成。这表明,捕食者对持续气候变暖的快速微进化可能会通过食物网传播产生间接的跨代生态后果。