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SUMMARY:EESS talk on "Microbial iron cycling in permafrost peatlands - Imp
 act on organic carbon mobilisation and greenhouse gas emissions"
DTSTART:20221122T121500
DTEND:20221122T131500
DTSTAMP:20260506T114701Z
UID:cf9d3b978a44d5667c80799266879ff39a15233b845cc3e306c4437a
CATEGORIES:Conferences - Seminars
DESCRIPTION:Dr Andreas Kappler\, Professor\, Center for Applied Geoscience
  Geomicrobiology\, Department of Geosciences\, Eberhard-Karls-University T
 uebingen\, DE\nAbstract:\nPermafrost peatlands hold enormous amounts of or
 ganic carbon\, equivalent to over one-third of the carbon currently in the
  atmosphere (∼800 Pg). Up to 20% of the total organic carbon is bound to
  reactive iron (Fe) minerals in the active layer overlying intact permafro
 st\, potentially protecting the organic carbon from microbial degradation 
 and transformation into greenhouse gases (GHG) such as CO2 and CH4. In th
 is project we study how mineral iron stability and microbial processes inf
 luence mineral dissolution during permafrost thaw and determine the implic
 ations for carbon cycling and GHG emissions in a permafrost peatland in Ab
 isko\, Sweden. We found that iron mineral dissolution by fermentative and 
 dissimilatory iron(III) reduction releases aqueous Fe2+ and aliphatic org
 anic compounds along collapsing palsa hillslopes. Microbial community anal
 ysis and carbon emission measurements indicate that this release is accomp
 anied by an increase in methanogen abundance and methane emissions at the 
 collapsing front. In summary\, our findings suggest that dissolution of re
 active iron minerals contributes to carbon dioxide and methane production 
 and emission\, even before complete permafrost thaw.\n\nShort biography:\n
 Prof. Andreas Kappler studied chemistry at University of Konstanz (Germany
 ) where he then also got his PhD in Environmental Microbiology working on 
 iron biogeochemistry in lake sediments and organic matter transformation i
 n soil-feeding termites. He then did a first postdoc at EAWAG (ETH Zürich
 ) in Environmental Chemistry where he studied the interactions of redox-ac
 tive natural organic matter with contaminants. His then did a second Postd
 oc at Caltech in Pasadena working on the role of phototrophic Fe(II) oxida
 tion in the deposition of Banded Iron Formations. He then returned to Germ
 any where he started his research group at University of Tuebingen. His cu
 rrent group has ca. 30 members and is focusing on microbial formation and 
 transformation of (iron) minerals and the environmental implications for n
 utrients\, contaminants and greenhouse gases.
LOCATION:GC B1 10 https://plan.epfl.ch/?room==GC%20B1%2010 https://epfl.zo
 om.us/j/63802032408
STATUS:CONFIRMED
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