Glacier-fed streams (GFSs) are extreme and rapidly vanishing ecosystems, and yet they harbor diverse microbial communities. Although our understanding of the GFS microbiome has recently increased, we do not know which microbial clades are ecologically successful in these ecosystems, nor do we understand potentially underlying mechanisms. Ecologically successful clades should be more prevalent across GFSs compared to other clades, which should be reflected as clade-wise distinctly low phylogenetic turnover. However, methods to assess such patterns are currently missing. Here we developed and applied a novel analytical framework, “phyloscore analysis”, to identify clades with lower spatial phylogenetic turnover than other clades in the sediment microbiome across twenty GFSs in New Zealand. These clades constituted up to 44% and 64% of community α-diversity and abundance, respectively. Furthermore, both their α-diversity and abundance increased as sediment chlorophyll a decreased, corroborating their ecological success in GFS habitats largely devoid of primary production. These clades also contained elevated levels of putative microdiversity than others, which could potentially explain their high prevalence in GFSs. This hitherto unknown microdiversity may be threatened as glaciers shrink, urging towards further genomic and functional exploration of the GFS microbiome.

冰川喂养的溪流 (GFS) 是极端且迅速消失的生态系统，但它们却拥有多样化的微生物群落。尽管我们对 GFS 微生物组的了解最近有所增加，但我们不知道哪些微生物进化枝在这些生态系统中在生态上是成功的，我们也不了解潜在的潜在机制。与其他进化枝相比，生态成功的进化枝在 GFS 中应该更普遍，这应该反映为进化枝明显低的系统发育更新。然而，目前缺少评估这种模式的方法。在这里，我们开发并应用了一种新的分析框架“phyloscore 分析”，以识别在新西兰 20 个 GFS 的沉积物微生物组中空间系统发育周转率低于其他进化枝的进化枝。这些进化枝分别占群落 α-多样性和丰度的 44% 和 64%。此外，它们的α多样性和丰度都随着沉积物叶绿素的增加而增加a减少，证实了它们在基本上没有初级生产的 GFS 栖息地中的生态成功。这些进化枝还包含比其他进化枝更高水平的推定微多样性，这可能解释了它们在 GFS 中的高流行率。随着冰川缩小，这种迄今为止未知的微多样性可能会受到威胁，这促使人们对 GFS 微生物组进行进一步的基因组和功能探索。