Warming alters the top-down effect of a common mesopredator in an aquatic food web

Global warming is altering the composition and functioning of both terrestrial and aquatic ecosystems. Most research has focussed on direct effects of warming on species and their population dynamics, while less is known about indirect effects through species interactions. Trophic cascades are especially likely to influence the effects of warming given that trophic levels differ in their response to warming because of differences in metabolism and vital rates such as growth and reproduction. We investigated if the top-down effect of a common mesopredator, the threespine stickleback, alters the impact of warming on a Baltic Sea food web. We manipulated both temperature and the presence of stickleback in mesocosms, and found the stickleback to alter the impact of warming on lower trophic levels. This was through increased consumption of herbivores that exceeded the rate at which the herbivore population could grow under higher temperature, which in turn increased algae biomass compared to..., , , # Warming alters the top-down effect of a common mesopredator in an aquatic food web The dataset was directed to temperature impact on the lower trophic organisms of threespine stickleback. The data were collected from a mesocosm experiment following a two-way factorial design, incorporating two climate settings (normal and high) and two levels of stickleback presence (absent/present). This experiment was conducted in two separate climate chambers. One density of stickleback (2 individuals/m2) was applied. Each treatment comprised 8 replicates altogether 32 replicates for the complete experiment. Condition in tanks imitated natural conditions in the field that were associated with herbivores and primary production. Following the experiment, the impact of treatments was recorded for the total biomass of algae, abundance of amphipods, and gastropods. From Mesocosmdata_Tawfiqur.xlsx | Variable name | Variable definition | Unit | | -------------------- |...全球变暖正在改变陆地与水生生态系统的组成与功能。当前多数研究聚焦于变暖对物种及其种群动态的直接影响，而对经由物种互作产生的间接效应的认知仍较为匮乏。鉴于不同营养级的代谢速率、生长与繁殖等生命特征存在差异，使其对变暖的响应各不相同，因此营养级联（trophic cascades）效应极易受到变暖的调控。本研究以波罗的海（Baltic Sea）食物网为研究对象，旨在探究常见中型捕食者——三刺棘鱼（threespine stickleback）的下行调控效应（top-down effect）是否会改变变暖对该食物网的影响。我们通过中宇宙（mesocosm）实验同时操控温度与棘鱼的存在状态，结果发现棘鱼能够改变变暖对低营养级生物的影响：在高温条件下，棘鱼对植食动物的捕食量提升，超过了植食动物种群在高温下的增长速率，进而使得藻类生物量相较于…… # 变暖改变水生食物网中常见中型捕食者的下行调控效应 本数据集聚焦于三刺棘鱼对低营养级生物的温度影响效应。 数据源自一项采用双因素析因设计的中宇宙实验，设置了两种温度情境（常温与高温）以及两种棘鱼存在水平（存在/缺失）。实验在两台独立的气候箱中开展，棘鱼密度统一设置为2尾/平方米。每个处理组包含8个重复，完整实验共计32个重复。实验容器的环境条件模拟了野外与植食动物及初级生产相关的自然生境。实验结束后，记录了各处理组对藻类总生物量、端足类（amphipods）丰度以及腹足类（gastropods）丰度的影响。 数据文件为Mesocosmdata_Tawfiqur.xlsx，变量信息如下表所示： | 变量名称 | 变量定义 | 单位 | | :-------------- | :------------------------------- | :----- | | （原文省略） | ... | |