Assembly Processes and Co-occurrence Networks of Core and Random Bacterial Communities in Cryoconite-Related Habitats on the Tibetan Plateau

Cryoconite-related habitats on the Tibetan Plateau represent key zones of microbial diversity and geochemical cycling on glacier surfaces, yet the assembly mechanisms and co-occurrence relationships of core versus random bacterial communities remain poorly understood. Using spatial abundance distributions (SpADs) to delineate core and random taxa, we found that both exhibited similar biogeographical patterns, though core communities were more sensitive to geographical and environmental variations. Deterministic and stochastic processes jointly governed core community assembly, whereas random communities were primarily shaped by stochasticity. Network analysis revealed higher functional complexity and diversity in random communities, which were crucial for network stability. Although directional transitions between core and random species were observed, this study provides the new insights into bacterial community assembly and interactions in Tibetan cryoconite habitats, advancing our understanding of microbial dynamics in these unique ecosystems.