Microbial community structure and methane dynamics in subarctic freshwater ecosystems influenced by permafrost thaw (Yukon, Canada)

This study investigates prokaryotic community composition, specifically focusing on bacteria and archaea, in relation to methane cycling across 16 subarctic waterbodies in the Yukon Territory (Canada), characterized by extensive discontinuous ice-rich permafrost. Samples were collected from various depths in lakes, ponds, and thermokarst meltwaters, representing diverse geomorphological conditions. Microbial communities were analyzed through high-throughput sequencing of the 16S rRNA gene (V4-V5 region). Sampling involved filtering water through sequential membranes (100 µm, 30 µm, and 0.2 µm), followed by optimized DNA extraction procedures adapted for low biomass environments. Results provide insights into how permafrost thaw shapes microbial ecology and methane biogeochemistry in these vulnerable northern ecosystems.