New paper on the effect of nitrate on Greenland supraglacial microbes

Tropospheric nitrate levels are predicted to increase throughout the 21st century, with potential effects on terrestrial ecosystems, including the Greenland ice sheet (GrIS).

A new study published in Environmental Microbiology Reports, with Marek as co-author, considers the impacts of elevated nitrate concentrations on the abundance and composition of prokaryotic communities on the GrIS surface. Nitrate concentrations were successfully elevated within sediment-filled meltwater pools, known as cryoconite holes; however, nitrate additions applied to surface ice did not persist. Estimated bulk and active cryoconite community cell abundance was unaltered by nitrate additions when compared to control holes using a quantitative PCR approach, and nitrate was found to have minimal affects on the dominant 16S rRNA gene-based community composition. Together, these results indicate that sampled cryoconite communities were not nitrate limited at the time of sampling. Instead, temporal changes in biomass and community composition were more pronounced.

Cameron KA, Stibal M, Chrismas N, Box J, Jacobsen CS (2017) Nitrate addition has minimal short-term affects on Greenland ice sheet supraglacial prokaryotes. Environmental Microbiology Reports doi 10.1111/1758-2229.12510

Greenland ice sheet surface