Greenhouse gas fluxes in the Arctic

Research at the Institute of Soil Science, University of Hamburg

Soils affected by permafrost are characteristic of Arctic regions. In these soils, permafrost lies beneath a layer that thaws in the summer, and these soils contain large amounts of organic carbon. Due to the current above-average warming of the Arctic, organic soil material is increasingly being decomposed by microorganisms. This produces the greenhouse gases nitrous oxide, methane, and carbon dioxide, which are then released from the soil into the atmosphere. How much nitrous oxide, methane and carbon dioxide is actually released depends on a number of factors, including temperature, water content, vegetation cover and nutrient availability. As a result, the levels and ratios of greenhouse gas emissions vary widely over small spatial scales. We are investigating how these factors interact to affect greenhouse gas emissions. We are also investigating how ecosystems will respond to the rapidly changing Arctic climate in the future. In our projects, experts in empirical field and laboratory research work closely with modeling scientists.

Research questions

  • How do permafrost-influenced ecosystems respond to climate change?
  • How do different soil processes affect the emission or absorption of greenhouse gases?
  • What is the role of Arctic regions in the global carbon cycle?
  • How strong is the climate-permafrost carbon feedback and how do permafrost-influenced ecosystems influence future climate?

Methods

  • Field measurements, e.g. greenhouse gas fluxes with chamber and eddy covariance methods, thaw depth, soil moisture, soil chemistry, stream water analysis
  • Determination of general soil properties and stable isotopes of water, carbon and nitrogen
  • Laboratory incubation studies, e.g. under controlled temperature, moisture or nutrient conditions
  • Mesocosm experiments in the laboratory under controlled conditions
  • Model experiments at different spatial scales

Responsible persons

Prof. Dr. Christian Beer, Institute of Soil Science, University of Hamburg

Prof. Dr. Lars Kutzbach, Institute of Soil Science, University of Hamburg

PD Dr. Christian Knoblauch, Institute of Soil Science, University of Hamburg

Dr. Carolina Voigt, Institute of Soil Science, University of Hamburg

Projects we participate in

MOMENT

Permafrost Research Towards Integrated Observation and Modelling of the Methane Budget of Ecosystems

CLICCS A1

Carbon dynamics in the Arctic

COLDSPOT

Arctic greenhouse gas sinks: exploring coldspots of methane and nitrous oxide in the permafrost domain (as a bridge group with the Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research)