Data from: Tracking climate change in a dispersal-limited species: reduced spatial and genetic connectivity in a montane salamander

Tropical montane taxa are often locally adapted to very specific climatic conditions, contributing to their lower dispersal potential across complex landscapes. Climate and landscape features in montane regions affect population genetic structure in predictable ways, yet few empirical studies quantify the effects of both factors in shaping genetic structure of montane-adapted taxa. Here, we considered temporal and spatial variability in climate to explain contemporary genetic differentiation between populations of the montane salamander, Pseudoeurycea leprosa. Specifically, we used ecological niche modelling (ENM) and measured spatial connectivity and gene flow (using both mtDNA and microsatellite markers) across extant populations of P. leprosa in the Trans-Mexican Volcanic Belt (TVB). Our results indicate significant spatial and genetic isolation among populations, but we cannot distinguish between isolation by distance over time or current landscape barriers as mechanisms shaping population genetic divergences. Combining ecological niche modelling, spatial connectivity analyses, and historical and contemporary genetic signatures from different classes of genetic markers allows for inference of historical evolutionary processes and predictions of the impacts future climate change will have on the genetic diversity of montane taxa with low dispersal rates. Pseudoeurycea leprosa is one montane species among many endemic to this region and thus is a case study for the continued persistence of spatially and genetically isolated populations in the highly biodiverse TVB of central Mexico.

热带山地类群通常局部适应极为特定的气候条件，这导致其在复杂地形中的扩散潜力较低。山地区域的气候与景观特征以可预测的方式影响种群遗传结构，但目前鲜有实证研究同时量化这两类因素对山地适应类群遗传结构的塑造作用。本研究以分布于跨墨西哥火山带（Trans-Mexican Volcanic Belt, TVB）的山地蝾螈Pseudoeurycea leprosa的现存种群为研究对象，通过考量气候的时空变异，解析该物种种群间的当代遗传分化。具体而言，我们运用生态位模型（ecological niche modelling, ENM），并结合线粒体DNA（mtDNA）与微卫星标记（microsatellite markers），对该蝾螈种群的空间连通性与基因流进行了测算。研究结果显示，种群间存在显著的空间与遗传隔离，但我们无法区分究竟是长期的距离隔离效应，还是当前的景观屏障机制，塑造了种群间的遗传分化。整合生态位模型、空间连通性分析，以及不同类别遗传标记所携带的历史与当代遗传信号，可用于推断历史演化过程，并预测未来气候变化对低扩散速率山地类群遗传多样性的影响。Pseudoeurycea leprosa是该区域众多特有山地物种之一，因此可作为研究案例，用以解析墨西哥中部生物多样性极高的跨墨西哥火山带中，空间与遗传隔离种群的持续存续机制。