The effect of temperature change on the microbial diversity and community structure along the chronosequence of the sub-arctic glacier forefield of Styggedalsbreen (Norway)

Microbial communities in the glacier forefield of Styggedalsbreen, Norway, were investigated along a chronosequence from newly exposed soil to vegetated soils using next-generation sequencing of the 16S rRNA gene. In order to monitor the short-term effect of temperature on community successions along the soil gradient, the soil samples were incubated at three different temperatures (5 degrees C, 10 degrees C and 22 degrees C). The microbial community composition along the chronosequence differed according to distance from the glacial terminus and incubation temperature. Samples close to the glacier terminus were dominated by Proteobacteria at 5 degrees C and 10 degrees C, while at 22 degrees C members of Chloroflexi, Acidobacteria and Verrucomicrobia in addition to Proteobacteria accounted for most of the diversity, indicating that sites close to the glacier terminus are more closely related to former subglacial environments. Within the Archaea domain, members of the phylum Euryarchaeota dominated in samples closer to the glacier terminus with a shift to members of the phyla Thaumarchaeota-Crenarchaeota with increased soil age. Our data indicate that composition and diversity of the microbial communities along the glacier forefield depend not only on exposure time but are also to a large degree influenced by soil surface temperature and soil maturation.