Karen Cameron, postdoc GEUS/CENPERM
Microbial community structures vary across the Greenland ice sheet surface
The composition and spatial variability of microbial communities that reside within the extensive (>200 000 km2) biologically active area encompassing the Greenland ice sheet (GrIS) is hypothesised to be variable. In this presentation bacterial communities from cryoconite debris and surface ice across the GrIS, are examined using sequence analysis and quantitative PCR of 16S rRNA genes from co-extracted rDNA and rRNA. Communities were found to differ across the ice sheet, with 82.8% of the total calculated variation being accounted for by spatial distribution on a scale of tens of kilometres 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 rDNA and rRNA amplicon libraries 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. We find that bacterial communities across the GrIS are spatially variable active communities that are likely influenced by localised biological inputs and physico-chemical conditions.
PLUS: a brief report from my 2015 field sampling.
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