Microbiomes shape ecosystems through functional profiles influenced by gene gains and losses. While culture-based experiments demonstrate that mobile genetic elements (MGEs) can mediate gene flux, quantitative field data remains scarce. Here we leverage large-scale soil meta-omic data to develop and apply analytics for studying MGEs. In our model permafrost-thaw ecosystem, Stordalen Mire, we identify ~2.1 million MGE recombinases across 89 microbial phyla to assess ecological distributions, functions impacted, and past mobility and current activity. This revealed MGEs shape natural genetic diversity via lineage-specific engagement, and functions including canonical defense elements alongside diverse regulatory and metabolic genes affecting carbon flux and nutrient cycling. These findings and this systematic meta-omic framework open new avenues to better investigate MGE diversity, activity, mobility, and impacts in nature.One Sentence Summary By developing microbiome-ready analytics and applying them to thawing permafrost microbiomes, we identified ~2.1 million diverse mobile genetic element (MGE) recombinases (integrons, insertion sequences, transposons, conjugative elements, phage-like elements) and revealed their function and activity to establish baseline ecological data and a framework for MGE study in complex natural systems.Competing Interest StatementThe authors have declared no competing interest.