Journal ArticleDOI
High microbial activity on glaciers: importance to the global carbon cycle
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TLDR
The results suggest that glaciers, which contain 75% of the freshwater of the planet, are largely autotrophic systems, but most lakes and rivers are generally considered as heterotrophic Systems.Abstract:
Cryoconite holes, which can cover 0.1–10% of the surface area of glaciers, are small, water-filled depressions (typically o1 m in diameter and usually o0.5 m deep) that form on the surface of glaciers when solar-heated inorganic and organic debris melts into the ice. Recent studies show that cryoconites are colonized by a diverse range of microorganisms, including viruses, bacteria and algae. Whether microbial communities on the surface of glaciers are actively influencing biogeochemical cycles or are just present in a dormant state has been a matter of debate for long time. Here, we report primary production and community respiration of cryoconite holes upon glaciers in Svalbard, Greenland and the European Alps. Microbial activity in cryoconite holes is high despite maximum temperatures seldom exceeding 0.11C. In situ primary production and respiration in cryoconites during the summer is often comparable with that found in soils in warmer and nutrient richer regions. Considering only glacier areas outside Antarctica and a conservative average cryoconite distribution on glacial surfaces, we found that on a global basis cryoconite holes have the potential to fix as much as 64 Gg of carbon per year (i.e. 98 Gg of photosynthesis minus 34 Gg of community respiration). Most lakes and rivers are generally considered as heterotrophic systems, but our results suggest that glaciers, which contain 75% of the freshwater of the planet, are largely autotrophic systems.read more
Citations
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Glaciers as a source of ancient and labile organic matter to the marine environment
Eran Hood,Jason B. Fellman,Jason B. Fellman,Robert G. M. Spencer,Robert G. M. Spencer,Peter J. Hernes,Richard T. Edwards,David V. D'Amore,Durelle T. Scott +8 more
TL;DR: Streamwater DOM is characterized from 11 coastal watersheds on the Gulf of Alaska that vary widely in glacier coverage and the bioavailability of DOM to marine microorganisms is significantly correlated with increasing 14C age, indicating that glacial runoff is a quantitatively important source of labile reduced carbon to marine ecosystems.
Journal ArticleDOI
Diversity and ecology of psychrophilic microorganisms.
Rosa Margesin,Vanya Miteva +1 more
TL;DR: Recent knowledge on the abundance, on the taxonomic and functional biodiversity, on low temperature adaptation and on the biogeography of microbial communities in a range of aquatic and terrestrial cold environments are summarized.
Journal ArticleDOI
Glacier shrinkage driving global changes in downstream systems
Alexander M. Milner,Alexander M. Milner,Kieran Khamis,Tom J. Battin,John E. Brittain,Nicholas E. Barrand,Leopold Füreder,Sophie Cauvy-Fraunié,Gísli Már Gíslason,Dean Jacobsen,David M. Hannah,Andy Hodson,Eran Hood,Valeria Lencioni,Jón S. Ólafsson,Christopher T. Robinson,Martyn Tranter,Lee E. Brown +17 more
TL;DR: It is concluded that human society must plan adaptation and mitigation measures for the full breadth of impacts in all affected regions caused by glacier shrinkage, and changes in river hydrology and morphology caused by climate-induced glacier loss are projected to be the greatest of any hydrological system.
Journal ArticleDOI
Microbial ecology of the cryosphere: sea ice and glacial habitats
TL;DR: This Review summarizes current knowledge of the microbial ecology of frozen waters, including the diversity of niches, the composition of microbial communities at these sites and their biogeochemical activities.
Journal ArticleDOI
Glaciers and ice sheets as a biome
TL;DR: It is suggested that it is time to recognise the cryosphere as one of the biomes of Earth.
References
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Journal ArticleDOI
Plumbing the Global Carbon Cycle: Integrating Inland Waters into the Terrestrial Carbon Budget
Jonathan J. Cole,Yves T. Prairie,Nina F. Caraco,William H. McDowell,Lars J. Tranvik,Robert G. Striegl,Carlos M. Duarte,Pirkko Kortelainen,John A. Downing,Jack J. Middelburg,John M. Melack +10 more
TL;DR: In this paper, the role of inland water ecosystems in the global carbon cycle has been investigated and it is shown that roughly twice as much C enters inland aquatic systems from land as is exported from land to the sea, roughly equally as inorganic and organic carbon.
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Photosynthetic rates derived from satellite‐based chlorophyll concentration
TL;DR: In this paper, a light-dependent, depth-resolved model for carbon fixation (VGPM) was developed to understand the critical variables required for accurate assessment of daily depth-integrated phytoplankton carbon fixation from measurements of sea surface pigment concentrations (Csat)(Csat).
Journal ArticleDOI
Respiration rates in bacteria exceed phytoplankton production in unproductive aquatic systems
TL;DR: It is reported here that bacterial respiration is generally high, and tends to exceed phytoplankton net production in unproductive systems, suggesting that in un productive aquatic systems, the biological system is a net source of CO2.
Journal ArticleDOI
Carbon in catchments: connecting terrestrial carbon losses with aquatic metabolism
Jonathan J. Cole,Nina F. Caraco +1 more
TL;DR: In this paper, the authors used the Hudson River catchment of North America to investigate the magnitude of net heterotrophy in aquatic ecosystems and found that respiration (R ) exceeds autochthonous gross primary production (GPP) in a majority of aquatic ecosystems.
Journal ArticleDOI
Role of lakes for organic carbon cycling in the boreal zone
Grete Algesten,Sebastian Sobek,Ann-Kristin Bergström,Anneli Ågren,Lars J. Tranvik,Mats Jansson +5 more
TL;DR: In this paper, the authors calculated the carbon loss (mineralization plus sedimentation) and net CO2 escape to the atmosphere for 79,536 lakes and total running water in 21 major Scandinavian catchments.