Habitat heterogeneity drives microbial community assembly and functional specialization in extremely arid ecosystems

Understanding microbial adaptation in hyperarid environments is crucial for predicting ecosystem responses to extreme stressors. This study provides an integrative framework linking environmental heterogeneity to microbial community assembly and metabolic specialization across diverse habitats in one of Earth's driest basins. Our findings demonstrate that deterministic environmental filtering dominates community assembly in deserts and moderately saline lakes, whereas stochastic processes prevail in wastelands and hypersaline systems. Habitat‑specific metabolic specialization is evident, with nitrogen cycling being key in terrestrial soils and sulfur metabolism central to saline lakes. By significantly improving the recovery of uncultured diversity through targeted strategies, this study bridges a major gap between molecular surveys and cultivable microorganisms. These findings advance ecological theory on community assembly and offer a model for studying microbial resilience and functional evolution under extreme aridity.