Microbial Functional Traits Enable Adaptation and Drive Biogeochemistry in Cryospheric Ecosystems

Glacier foreland and permafrost microbiomes exhibit distinct taxonomic and functional specialization adapted to extreme cold. Metagenomic analysis reveals dominance of Thermoproteota and Methanobacteriota in archaea, Ascomycota and Basidiomycota in eukaryotes, and enriched Actinomycetota, Planctomycetota, and Gemmatimonadota in bacteria, compared to temperate sediments. Genus‐level distributions further reflect niche partitioning, with cold‐adapted taxa such as Pseudogymnoascus (fungi) and pigment‐producing/cold‐shock protein‐encoding bacteria enriched in frozen habitats. Genetically, these communities are fortified with DNA repair, osmoregulation, and cold‐shock genes, supporting resilience under UV, osmotic, and freezing stress. Functionally, they show enhanced polysaccharide degradation and Type II methanotrophy but constrained denitrification. Network analysis identified four microbial modules, each representing specialized strategies for nutrient cycling, methane metabolism, phototrophic symbiosis, and resource scavenging in cold environments through cross‐domain collaboration and metabolic complementarity. Collectively, this study advances our understanding of extremophile life by demonstrating that microbial survival in cryospheric ecosystems is orchestrated through a sophisticated integration of community composition, genetic inventory, and interspecies cooperation. These insights are essential for predicting the ecological responses and climate feedbacks of cryospheric ecosystems under global warming.