Environmental filters of freshwater fish community assembly along elevation and latitudinal gradients

Aim The aim was to identify drivers of historical freshwater fish community assembly by testing for interactions between functional traits and two climatic gradients, namely elevation and latitude. Many studies conclude that environmental filtering is the dominant process of community-wide trait convergence at high elevations and high latitudes, but a full understanding of which specific filters cause trait convergence is lacking. Location Great Plains–Rocky Mountains, USA. Time period 1960–2018. Major taxa studied Freshwater fish. Methods Using 2,539 stream fish community surveys documenting the native distributions of 51 species, we evaluated trait–environment relationships (trade-offs) and trait–dispersion relationships (standardized effect sizes from null models) along elevation and latitudinal gradients in four functional trait categories. We tested whether elevation and latitude exhibited similar trait–environment and trait–dispersion r...研究目标 本研究旨在通过检验功能性状（functional traits）与海拔、纬度两类气候梯度间的交互作用，明确历史淡水鱼类群落构建的驱动因子。既往多项研究指出，环境过滤是高海拔与高纬度区域群落水平性状趋同的主导过程，但目前仍缺乏对引发性状趋同的具体过滤因子的全面认知。 研究区域 美国大平原-落基山脉区域。 研究时段 1960年—2018年。 研究类群 淡水鱼类。 研究方法 本研究整合了2539份溪流鱼类群落调查数据，涵盖51个本土分布物种，沿海拔与纬度梯度，针对四类功能性状类别评估了性状-环境关联（即性状权衡关系）以及性状-离散度关联（即基于零模型（null models）计算得到的标准效应量（standardized effect sizes））。本研究检验了海拔与纬度在性状-环境及性状-离散度方面是否呈现相似的……