Stephanodiscus niagarae Ehrenberg is currently restricted to specific regions of central Mexico, however, during the late Pleistocene, it had a wider distribution in the country. This change in distribution is similar to those observed for several organisms that migrated southwards during cold, glacial climates, supporting the hypothesis that central Mexico acted as glacial refugia for these species. This study aims to support this hypothesis for S. niagarae as well as to analyze its ecological distribution in modern environments in central Mexico. For this purpose we studied 18 samples from 16 lakes located around Mexico City, selected among 46 lakes along the Trans-Mexican Volcanic Belt. Diatom assemblages in superficial sediments, and climatic, hydrochemistry, and nutrient parameters of each lake were analyzed by means of canonical correspondence analyses. Additionally, we created an ecological niche model (ENM) with modern occurrence data (n = 47) and environmental variables (WorldClim) to produce potential distribution maps of S. niagarae during the present time and under the LGM conditions in the Nearctic realm. S. niagarae was recorded only in 4 sites in central Mexico (abundances < 10%) associated with temperate, subhumid conditions in freshwater lakes with [Mg²⁺] − [Ca²⁺] − [HCO₃⁻] ionic dominance and high turbidity, mesotrophic to hypertrophic systems (based on chlorophyll a values), but with a tendency to P-limitation. In our study sites S. niagarae showed low abundances in diatom assemblages dominated by Aulacoseira spp. Temperature (annual mean, coldest and warmest quarters means) was identified by ENM as the main environmental variable controlling its distribution, with its highest modern support in the USA, southern Canada, and a restricted distribution in the highlands of western and central Mexico. Whereas, the LGM scenario (− 5.5 °C) identified the western and central highlands in Mexico and southern USA as the highest probability distribution areas supporting the approach that the Sierra Madre Occidental could have acted as a migration corridor offering suitable habitats for a southward migration into central Mexico during colder (glacial) periods. In conclusion, S. niagarae distribution in the central and western mountains of Mexico is controlled by temperature changes and its presence may be associated with colder (glacial) periods.

目前，尼亚加拉氏无脊椎动物（Stephanodiscus niagarae Ehrenberg）仅限于墨西哥中部的特定地区，然而，在更新世晚期，它在该国的分布更为广泛。这种分布的变化与在寒冷的冰川气候下向南迁移的几种生物所观察到的变化相似，支持了墨西哥中部充当这些物种的冰川避难所的假说。这项研究旨在支持烟酒链球菌的这一假设。以及分析其在墨西哥中部现代环境中的生态分布。为此，我们研究了墨西哥城周围16个湖泊中的18个样本，这些样本是在跨墨西哥火山带的46个湖泊中选择的。通过典范对应分析，分析了浅层沉积物中的硅藻组合，以及每个湖泊的气候，水化学和养分参数。此外，我们用现代发生数据（n = 47）和环境变量（WorldClim）创建了一个生态位模型（ENM），以产生当前和在LGM环境下在LGM环境下烟酒链霉菌的潜在分布图。烟酒链球菌仅在与温带关联中央墨西哥（丰度<10％）4个位点被记录，半湿润条件与[镁淡水湖²⁺ ] -的[Ca ²⁺ ] - [HCO ₃ ^- ]的离子支配地位和高浊度，中营养至肥大系统（基于叶绿素a值），但具有P限制的趋势。在我们的研究地点中，S。niagarae在以Aulacoseira为主的硅藻组合物中显示出低丰度spp。ENM将温度（年平均，最冷和最暖季的平均温度）确定为控制其分布的主要环境变量，在美国，加拿大南部获得最高的现代支持，而在墨西哥西部和中部高地则受到限制。鉴于LGM情景（-5.5°C）确定了墨西哥和美国南部的西部和中部高地是概率最高的分布区域，这支持了西马德雷山脉可能作为移民走廊为南部迁移提供合适的栖息地的方法在较冷的（冰川）时期进入墨西哥中部。最后，烟酒链球菌 墨西哥中西部山区的分布受温度变化的控制，其存在可能与较冷的（冰川）时期有关。