Data from: Climate and local abundance in freshwater fishes

Identifying factors regulating variation in numbers of individuals among populations across a species’ distribution is a fundamental goal in ecology. A common prediction, often referred to as the abundant-centre hypothesis, suggests that abundance is highest near the center of a species’ range. However, because of the primary focus on the geographic position of a population, this framework provides little insight into the environmental factors regulating local abundance. While range-wide variation in population abundance associated with environmental conditions has been investigated in terrestrial species, the relationship between climate and local abundance in freshwater taxa across species’ distributions is not well understood. We used GIS-based temperature and precipitation data to determine the relationships between climatic conditions and range-wide variation in local abundance for 19 species of North American freshwater fishes. Climate predicted a portion of the variation in local abundance among populations for 18 species. In addition, the relationship between climatic conditions and local abundance varied among species, which is expected as lineages partition the environment across geographic space. The influence of local habitat quality on species persistence is well-documented; however, our results also indicate the importance of climate in regulating population sizes across a species geographic range, even in aquatic taxa.明确调控物种分布范围内不同种群个体数量变异的影响因子，是生态学领域的核心研究目标之一。其中一个被广泛引用的预测框架，即丰度中心假说（abundant-center hypothesis），提出物种的种群丰度在其分布范围的中心区域达到峰值。然而，该假说主要聚焦于种群的地理区位，几乎无法为解析调控局域种群丰度的环境因子提供有效洞见。尽管针对陆生类群，学界已开展了与环境条件相关的种群丰度全分布区变异研究，但淡水类群中气候与跨物种分布范围的局域丰度之间的关联机制仍未得到充分阐释。本研究借助基于地理信息系统（GIS）获取的气温与降水数据，分析了19种北美淡水鱼类的气候条件与全分布区局域丰度变异之间的关联。结果显示，气候条件可解释18个物种的种群间局域丰度变异。此外，不同物种间气候与局域丰度的关联模式存在显著差异，这与不同演化支系在地理空间中对环境的分化利用的预期相符。局域生境质量对物种存续的影响已得到大量研究证实；而本研究结果同时表明，即便在水生类群中，气候在调控物种全地理分布范围内的种群规模方面同样发挥着关键作用。