Extreme heat events and the vulnerability of endemic montane fishes to climate change

Identifying how close species live to their physiological thermal maxima is essential to understand historical warm-edge elevational limits of montane faunas and forecast upslope shifts caused by future climate change. We used laboratory experiments to quantify the thermal tolerance and acclimation potential of four fishes (Notropis leuciodus, N. rubricroceus, Etheostoma rufilineatum, E. chlorobranchium) that are endemic to the southern Appalachian Mountains (USA), exhibit different historical elevational limits, and represent the two most species-rich families in the region. All-subsets selection of linear regression models using AICc indicated that species, acclimation temperature, collection location and month, and the interaction between species and acclimation temperature were important predictors of thermal maxima (Tmax), which ranged from 28.5 to 37.2°C. Next, we implemented water temperature models and stochastic weather generation to characterize the magnitude and frequency of ...

明确物种生存距离其生理热极限的贴近程度，对于解析山地动物群的历史热边缘海拔上限、预测未来气候变化引发的物种上坡迁移至关重要。本研究通过室内实验，量化了美国阿巴拉契亚山脉南部特有分布的4种鱼类（Notropis leuciodus、N. rubricroceus、Etheostoma rufilineatum、E. chlorobranchium）的热耐受性与驯化潜力；这4种鱼类均具有差异化的历史海拔上限，且分别隶属于该区域物种丰富度最高的两个鱼类科。基于校正赤池信息准则（Akaike Information Criterion Corrected, AICc）的线性回归模型全子集选择分析显示，物种种类、驯化温度、采样地点与采样月份，以及物种与驯化温度的交互作用，均为热最大值（Tmax）的重要预测因子，其取值范围为28.5至37.2℃。随后，本研究采用水温模型与随机天气生成方法，对...的强度与发生频率进行了表征。