Minnesota peat viromes reveal terrestrial and aquatic niche partitioning for local and global viral populations

Background: Peatlands are expected to experience sustained yet fluctuating higher temperatures due to climate change, leading to increased microbial activity and greenhouse gas emissions. Despite mounting evidence for viral contributions to these processes in thawing permafrost, little is known about viruses in other peatlands. More generally, soil viral biogeography and its potential drivers are poorly understood at both local and global scales. Here, 87 metagenomes and five viral size-fraction metagenomes (viromes) from a boreal peatland in Northern Minnesota (from the SPRUCE whole-ecosystem warming experiment and surrounding bog) were analyzed for dsDNA viral community ecological patterns, and the recovered viral populations (vOTUs) were compared to a database of 261,799 vOTUs from diverse ecosystems.

Results: Within the SPRUCE experiment, viral community composition was significantly correlated with peat depth, soil moisture, and carbon chemistry, including CH4 and CO2 concentrat...