The composition and spatial variability of microbial communities that reside within the extensive (>200 000 km(2)) biologically active area encompassing the Greenland ice sheet (GrIS) is hypothesized to be variable. We examined bacterial communities from cryoconite debris and surface ice across the GrIS, using sequence analysis and quantitative PCR of 16S rRNA genes from co-extracted DNA and RNA. Communities were found to differ across the ice sheet, with 82.8% of the total calculated variation attributed to spatial distribution on a scale of tens of kilometers separation. Amplicons related to Sphingobacteriaceae, Pseudanabaenaceae and WPS-2 accounted for the greatest portion of calculated dissimilarities. The bacterial communities of ice and cryoconite were moderately similar (global R = 0.360, P = 0.002) and the sampled surface type (ice versus cryoconite) did not contribute heavily towards community dissimilarities (2.3% of total variability calculated). The majority of dissimilarities found between cryoconite 16S rRNA gene amplicons from DNA and RNA was calculated to be the result of changes in three taxa, Pseudanabaenaceae, Sphingobacteriaceae and WPS-2, which together contributed towards 80.8 ± 12.6% of dissimilarities between samples. Bacterial communities across the GrIS are spatially variable active communities that are likely influenced by localized biological inputs and physicochemical conditions.

Center for Permafrost University of Copenhagen 1350 Copenhagen Denmark Department of Biology University of Copenhagen 2100 Copenhagen Denmark

Center for Permafrost University of Copenhagen 1350 Copenhagen Denmark Department of Environmental Science Aarhus University 4000 Roskilde Denmark

Department of Ecology Charles University Prague 128 43 Praha 2 Czech Republic

Department of Geochemistry Geological Survey of Denmark and Greenland University of Copenhagen 1350 Copenhagen Denmark

Department of Geochemistry Geological Survey of Denmark and Greenland University of Copenhagen 1350 Copenhagen Denmark Department of Ecology Charles University Prague 128 43 Praha 2 Czech Republic

References provided by Crossref.org

Storage and export of microbial biomass across the western Greenland Ice Sheet

Patterns in Microbial Assemblages Exported From the Meltwater of Arctic and Sub-Arctic Glaciers