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VERA Seminar

The Role of Arctic Soils in the Permafrost –  Climate Feedback

Andreas Richter, Department Microbiology and Ecosystem Science, University of Vienna and Austrian Polar Research Institute

The total organic carbon pool in arctic and boreal permafrost soils has been estimated to be about 1,760 Petagram (1015 g) C, more than twice today’s atmospheric C pool and about half of the global soil carbon. A significant proportion of this C pool may be vulnerable to climate warming through permafrost thawing and subsequent decomposition by microorganisms. Thus, it has been suggested that permafrost soils may become a future source of CO2 and CH4 to the atmosphere and lead to a strong positive feedback to global warming (up to + 0.5 °C until 2200).
I will present results from several projects that aimed at understanding the mechanisms behind the permafrost-climate feedback, by identifying the major soil organic matter (SOM) stabilization mechanisms of permafrost SOM. I will address a range of different mechanisms by which SOM can be protected from decomposition, such as unfavourable temperature and moisture regimes, physical protection by formation of organo-mineral associations and chemical recalcitrance of SOM. I will focus, however, on energy and nutrient constraints of heterotrophic microbial communities and their role in SOM decomposition. I will then show that the physiology of the tiniest organisms on Earth will ultimately determine the vulnerability of the global permafrost carbon pool and thus the global permafrost-climate feedback.

 

Donnerstag, 12.05.2016    16:30 Uhr

Victor-Franz-Hess-Hörsaal
Währinger Str. 17 (Kavalierstrakt, Zugang durch den Hof)
1090 Wien

 Ankündigung

Universität Wien
Isotopenforschung und Kernphysik

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