Microbial Nitrogen Cycling Genes in Arctic Streams

This study integrates molecular, environmental, and spatiotemporal data to examine the structure and function of streambed microbial communities across Arctic regions experiencing rapid climate change. Sediment samples were collected from 28 streams spanning four Arctic regions during summer 2021, including 15 Greenlandic streams that were sampled three times throughout the open-water season to capture temporal variation. Microbial community composition was characterized using 16S rRNA gene sequencing, while functional potential for nitrogen cycling was quantified through qPCR targeting six key genes involved in N-fixation (nifH), nitrification (amoA, nxrB), and denitrification (nirS, norB, nosZ). Environmental data included catchment characteristics, streamwater and sediment caractheristics. These molecular and environmental datasets were integrated with spatial and temporal sampling metadata to assess biogeographic and seasonal trends. Together, these data provide a comprehensive framework for understanding how Arctic stream microbial communities and nitrogen cycling functions respond to spatial heterogeneity and seasonal dynamics under ongoing climate change.