Baris Uzel

Arctic air temperatures are increasing at more than double the global rates with warming occurring predominantly in the winter months. Precipitation in the Arctic is expected to increase throughout the century causing enhanced snow deposition that can act as a soil insulator during the cold winter months. The combined effect of both these factors can influence soil microbial communities, biogeochemical cycles, and potentially surface water quality. Microbial activity during the winter can play a crucial role in ecosystem dynamics in the High Arctic. During the winter, fungal dominated microbial communities can access multiple mircosites through their mycelia and thereby mineralize greater amounts of nitrogen (N). This is a key process since Arctic ecosystems are N deficient which causes a limit to both vegetation and soil microbiome productivity during the growing season. Changes in the N cycle can also impact surface waters. Warmer winters can increase microbial productivity causing higher N mineralization rates, thereby, decrease N deficiency in the growing season which can trigger feedback mechanisms that could wither induce or dampen further warming. Baris' goal is to understand the effect of winter temperatures on nitrogen transformation rates in the Cape Bounty Arctic Watershed Observatory by conducting an incubation study using soil samples taken from a wet sedge tundra ecosystem.