Tundra moss transplants reveal host species-specific microbial communities and independent responses of associated N2 fixation rates to environmental change

This study investigates how climate, moss species, and microbial communities affect N2 fixation in the Alaskan tundra. OUr team conducted a transplant experiment study using two sites that differed in temperature, Healy and Toolik Lake, Alaska, and three moss speices: Hylocomium splendens, Aulacomnium turgidum, and Pleurozium schreberi. Our research combined 16S rRNA gene sequencing with 15N2 incubations. Results showed that N2 fixation rates were influenced more by climate and moss physiology than by microbial community shifts. Pleurozium schreberi increased N2 fixation in cooler conditions, while Aulacomnium turgidum's fixation rates were high regardless of location. This study highlights the complex interplay between biologic and physiochemical variables affecting nitrogen cycling in warming tundra ecosystems.