Atmospheric Microbial Transport to Antarctica and Its Ecological Implications: A Systematic Review.

Atmospheric transport is hypothesized to be the primary vector connecting isolated Antarctic terrestrial habitats to global microbial pools, yet the mechanisms governing this connectivity still have important gaps. We systematically reviewed the present knowledge on how the atmosphere acts not merely as a passive conduit, but potentially as a selective ecological filter and a particular ecosystem. Analysis of 53 studies reveals a three-pathway framework: (1) long-range advection via the free troposphere, (2) marine aerosolization from the Southern Ocean, and (3) local resuspension of soils, rock outcrops and cryoconite. Crucially, we identify indirect evidence suggesting that atmospheric transport imposes a strict selection regime dominated by UV irradiation and desiccation. This potential barrier likely ensures that successful colonizers are disproportionately enriched for stress-tolerance traits, including DNA repair and cold-active metabolism. Consequently, atmospheric deposition may not just add biomass; it could actively shape Antarctic ecosystems by seeding them with functionally distinct, stress-adapted pioneers capable of altering local nutrient cycling. We conclude that future research must move beyond simple detection to focus on the viability and metabolic competence of these airborne immigrants to predict their role in a warming Antarctic.