Microbial transformation of soil organic carbon in permafrost-affected soils and sediments

Carbon transformation (decomposition, humification, release) in permafrost affected landscapes is largely determined by the involved microbial communities and their activity. The active microorganisms are characterized by special adaptations to the extreme conditions of permafrost affected landscapes (e.g. low in situ temperature, limited oxygen supply). Research is needed on the extent and importance of the activity of relevant groups of microorganisms for the transformation of organic carbon and their response to changing environmental conditions in permafrost affected landscapes under global warming.

Ice complex on Kurungnakh. © C. Knoblauch
Coastal erosion on Samoylov. © C. Knoblauch

The overall objective of the project is a better understanding of microbially controlled transformation of soil organic matter and the associated release of greenhouse gases when recent and older permafrost deposits are starting to thaw. Therefore, the underlying microbial communities, their role in the mineralization of organic matter and their response to changing environmental conditions are examined by means of a combined research approach from microbial process studies, DNA-based diversity studies and lipid biomarker analysis. The data on current carbon dynamics are interpreted in the light of the results on previous climate cycles (glacial - interglacial) and are used to understand the future development of permafrost landscapes as a sink or source of climate-relevant trace gases.

Soil and ice core samples from Kurungnakh. © C. Knoblauch

Four different working groups are tasked with answering certain aspects of the overall scientific goal:

Institute of Soil Science, University of Hamburg– Microbial process studies
Dr. Christian Knoblauch, Josefine Walz

  • Quantification of aerobic and anaerobic mineralization of soil organic carbon of different functional soil carbon pools
  • Determination of the temperature sensitivity of soil organic matter mineralization in permafrost-affected soils and sediments

Sukachev Institute of Forest – Microbial process studies
Dr Svetlana Evgrafova, Dr. Irinia Grodnitzkaya, Sergei Syrtsov

  • Understanding processes of microbial communities involved in the transformation of soil organic carbon in permafrost-affected soils and sediments

German Research Center for Geosciences, Section 4.5: Geomicrobiology – DNA-based diversity studies
Prof. Dr. Dirk Wagner, Nadja Torres Reyes

  • Characterization of the role and identification of microorganisms involved in the transformation of organic carbon with special regards to arctic warming
  • Understanding the link between substrate composition and the microbial metabolic pathways within the carbon cycle

German Research Center for Geosciences, Section 4.3: Organic Geochemistry – Lipid biomarker analysis
Dr. Kai Mangelsdorf, Janina Stapel

  • Characterization of the distribution and composition of the living and fossil microbial communities involved in the methane cycle and reconstruction of paleo-methane dynamics
  • Structural characterization of the substrate potential of the stored organic matter for biodegradation and greenhouse gas production within permafrost deposits
Active layer samples from Samoylov. © J. Walz
Preparing incubation studies in the field laboratory on Samoylov. © J. Walz

News

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News from the summer expedition to the delta!

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In September 2016 our "St. Petersburg summer school" for young scientists will be supported by the DAAD "Go-East Summer Schools" programme.

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Our new bilateral Master's Program CORELIS will start with the first cohort in summer 2016!

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Great photographs from our Summer School at Lake Ladoga available on-line!

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Late summer on Samoylov Island. Read how our six scientists are going!

Scientists from Hamburg are in the Lena River Delta.

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Impressions of the Polar day, the spring flood and the ice breakup. 

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