Glacier chronosequences offer a unique opportunity to observe primary successional patterns and assess the interaction between biological communities and abiotic conditions. Bacteria are one of the first organisms to colonize such ecosystems, yet factors determining their distribution and diversity are still in need of understanding. In this study, we investigated the associated abiotic and biotic factors related to bacterial communities across post-glacial moraines at two localities in the Ladakh region of the Western Himalaya which differed in elevation and climate. By measuring soil chemistry, plant, biological soil crust, and bacterial community composition while accounting for moraine age and topography, we reveal the successional paths of multiple trophic levels at the highest elevation glacier forefields known to be studied. Biological soil crust communities followed a trajectory of being dominated by the order Chroococcales before transitioning to filamentous Nostocales and Oscillatoriales and eventually decreasing in cover as plants colonize the area. Using variation partitioning, we found bacterial communities in the higher locality, Tso Moriri (5800 m), were more associated with soil conditions, while at the lower location, Nubra (5150–5400 m), bacterial communities were more coupled with plant community composition. Furthermore, using generalized linear models, bacterial family richness was found to be significantly correlated with plant species richness, however, topography was also significant, indicating geomorphological depressions or gullies at the bottom of moraines potentially harbor higher bacterial richness prior to the advanced colonization of plants. These results suggest the community structure and successional pathways of bacteria and plants in glacier forefields are influenced by differing biotic and abiotic factors at different geographical locations and provides a local framework for the future of deglaciated environments.

冰川年代序列为观察主要演替模式和评估生物群落与非生物条件之间的相互作用提供了独特的机会。细菌是最早在此类生态系统中定居的生物体之一，但决定其分布和多样性的因素仍需要了解。在这项研究中，我们调查了喜马拉雅西部拉达克地区海拔和气候不同的两个地点的冰期后冰碛中与细菌群落相关的非生物和生物因素。通过测量土壤化学、植物、生物土壤结皮和细菌群落组成，同时考虑冰碛年龄和地形，我们揭示了已知研究的最高海拔冰川前田的多个营养级的演替路径。生物土壤结皮群落遵循以色球菌目为主的轨迹，然后过渡到丝状念珠菌目和颤藻目，并最终随着植物在该地区的殖民而减少覆盖范围。通过变异划分，我们发现地势较高的地方 Tso Moriri（5800 m）的细菌群落与土壤条件的相关性更强，而地势较低的 Nubra（5150-5400 m）的细菌群落与植物群落组成的关联性更强。此外，使用广义线性模型，发现细菌家族丰富度与植物物种丰富度显着相关，然而，地形也很重要，表明在植物高级定植之前，冰碛底部的地貌凹陷或沟壑可能蕴藏着更高的细菌丰富度。这些结果表明，冰川前场细菌和植物的群落结构和演替途径受到不同地理位置不同生物和非生物因素的影响，并为未来的消融环境提供了当地框架。