A climate-sensitive, contemporary multi-sphere bacterial metacommunity across the Tibetan Plateau

The Tibetan Plateau hosts interacting atmospheric, glacier, river, lake, and soil ecosystems, yet the organization and climatic sensitivity of their bacterial communities remain unclear. Here, we compiled a 16S rRNA gene dataset of 3373 samples across five ecosystems and nine habitats. More than 55% of Operational Taxonomic Units occurred in at least two ecosystems, and ∼6% in all five, thus revealing a metacommunity in which aerosols seed glacier microbiomes, and glaciers act as sinks, filters, and relays, exporting microbes to rivers, lakes, and soils. Nevertheless, community uniqueness and core microbiomes demonstrate robust habitat filtering and distinct biogeographic fingerprints. Mean annual precipitation exerts more potent effects on richness and community uniqueness than temperature or solar radiation, but exerts opposite influences on bacterial beta diversity in glacier versus downstream ecosystems. These findings provide novel insights into microbial interconnectedness and climate sensitivity in the Tibetan Plateau.