Environmental characteristics and changes of bacterial communities in the meltwater runoff of glacier in Ny-Alesund, Arctic

The present study assessed the diversity and composition of bacterial communities in glacial runoff and glacial soils in the Midre Lovénbreen glacier region of Svalbard. A total of 6,593 operational taxonomic units were identified by high-throughput sequencing. The results showed differences in bacterial community composition between the upper and lower reaches of glacial runoff. The abundance of Actinobacteria, Firmicutes, Betaproteobacteria and Gammaproteobacteria in the upper reaches of glacial runoff was higher than that in the lower reaches. In contrast, the the abundance of Cyanobacteria and Alphaproteobacteria in the downstream of glacial runoff was higher than that in the upstream. In addition, we compared bacterial diversity and composition between glacial runoff areas and soils. The chart analysis showed that bacterial diversity in glacial soil was higher than that in the glacial runoff. Some typical bacteria in the soil, such as Actinobacteria, entered glacial runoff through contact between them. The abundance of Acidobacteria, Sphingobacterium and Flavobacterium was higher in glacial soil. Weighted correlation network analysis showed that the core bacteria in glacial runoff and glacial soil were typical bacteria in different habitats. Distance-based redundancy analysis revealed that NO 2 - -N was the most significant factor affecting the distribution of soil bacterial community, while NO 3 - -N was the most significant factor affecting the distribution of glacial runoff bacterial community.