Biodiversity-mediated effects on ecosystem functioning depend on the type and intensity of environmental disturbances

Environmental disturbances affect ecosystem functioning through changes in organisms’ metabolism (direct effect) and biodiversity loss (indirect or biodiversity-mediated effect). It is still a challenge to separate direct and biodiversity-mediated effects of environmental changes on ecosystem functioning due to the difficulties in isolating ‘true’ biodiversity loss effects. Furthermore, it is still unclear whether biodiversity-mediated effects are as important as direct effects. In this study, we performed an experiment in artificial microcosms to disentangle biodiversity-mediated and direct effects of two major environmental disturbances on the functioning of aquatic ecosystems: increases in temperature and salinity. The ecosystem function analyzed was the microalgae predation by the zooplankton community (zooplankton grazing rates). Temperature and salinity increases affected the zooplankton grazing rates due to changes in community composition and abundance, as well as organism perfo...环境扰动可通过两种路径影响生态系统功能：其一为改变生物体代谢（直接效应），其二为引发生物多样性丧失（间接效应，即生物多样性介导效应）。由于难以分离‘真实’的生物多样性丧失效应，当前学界仍难以厘清环境变化对生态系统功能的直接效应与生物多样性介导效应。此外，目前尚不清楚生物多样性介导效应是否与直接效应同等重要。本研究借助人工微型生态系统（artificial microcosms）开展实验，旨在拆解温度升高与盐度升高这两种主要环境扰动对水生生态系统功能的直接效应与生物多样性介导效应。本研究分析的生态系统功能为浮游动物群落对微藻的捕食作用，即浮游动物摄食率（zooplankton grazing rates）。温度与盐度升高可通过改变群落组成与丰度，以及生物体生理性能（原文未完整收尾）影响浮游动物摄食率。