Article

Microbially driven export of labile organic carbon from the Greenland ice sheet

  • Nature Geoscience volume 10, pages 360365 (2017)
  • doi:10.1038/ngeo2920
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Abstract

Glaciers and ice sheets are significant sources of dissolved organic carbon and nutrients to downstream subglacial and marine ecosystems. Climatically driven increases in glacial runoff are expected to intensify the impact of exported nutrients on local and regional downstream environments. However, the origin and bioreactivity of dissolved organic carbon from glacier surfaces are not fully understood. Here, we present simultaneous measurements of gross primary production, community respiration, dissolved organic carbon composition and export from different surface habitats of the Greenland ice sheet, throughout the ablation season. We found that microbial production was significantly correlated with the concentration of labile dissolved organic species in glacier surface meltwater. Further, we determined that freely available organic compounds made up 62% of the dissolved organic carbon exported from the glacier surface through streams. We therefore conclude that microbial communities are the primary driver for labile dissolved organic carbon production and recycling on glacier surfaces, and that glacier dissolved organic carbon export is dependent on active microbial processes during the melt season.

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Acknowledgements

This study was funded by grants from the UK National Environment Research Council (NERC) NE/J02399X/1 to A.M.A., NERC Doctoral Training Program Grant to M.M., NERC grant NE/H023879/1 to J.W. and NERC studentships NE/152830X/1 and NE/J500021/1 to A.T. We would like to thank all members of the Greenland 2012 Leverett field team for their assistance during field work.

Author information

Author notes

    • Michaela Musilova

    Present address: Slovak Organisation for Space Activities (SOSA), Bratislava 812 19, Slovakia; Faculty of Electrical Engineering and Information Technology of the Slovak University of Technology, Bratislava, 812 19 Slovakia

    • Andrew Tedstone

    Present address: Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, UK (A.T.).

Affiliations

  1. Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, UK

    • Michaela Musilova
    • , Martyn Tranter
    • , Jemma Wadham
    • , Jon Telling
    •  & Alexandre M. Anesio
  2. School of Geoscience, University of Edinburgh, Edinburgh EH9 3FE, UK

    • Andrew Tedstone

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Contributions

M.M., A.M.A. and J.T. designed the overall study. M.T. and J.W. were involved in advising the detail of the study design. M.M. and A.T. collected the field data. M.M. performed the experiment and processed the data. M.M., A.M.A. and M.T. wrote the paper. All authors discussed the results and commented on the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Michaela Musilova.

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