Title: The carbon balance of a high-arctic ecosystem.


Aim: The overall objective of the project is to establish a carbon budget for a natural arctic ecosystem, and enhance the knowledge of the processes behind changes in the large pools of organic carbon in the arctic soils. It is the ambition that measurements of the carbon fluxes between the atmosphere and the surface together with studies of carbon fluxes in the soil and pore water can be integrated to achieve an accurate carbon balance on an ecosystem level. It is desirable that the effect of climatic change on the carbon balance of arctic ecosystems can be clarified through model studies.


Background: A large proportion of the Worlds soil organic carbon is stored in the arctic soils, and any change in this carbon stock will have significant consequences for the atmospheric content of greenhouse gases. As it is also widely accepted that the increase in temperature will be most pronounced in the high latitudes, it is of vital importance to clarify the effects of climate change on the carbon balance of the arctic soils. Though it is well known that the decomposition of organic soil matter, thus CO2 and CH4 production, is stimulated by increases in temperature and also dependent on moisture availability, the long term effects and inter-annual variability remains unclear. Further the direct effects of climate change on soil developing processes and carbon leaching in soils affected by permafrost needs further verification.


Project description: The successful candidate will be fully involved in the ongoing research at the scientific field station in Zackenberg in NE Greenland. Depending on research interests and background emphasis can be put in soil processes or atmospheric fluxes of CO2 and CH4, but elements of both is desirable in order to achieve the main objective of the project, namely to establish an accurate carbon balance for the area. An important part the project will be evaluation and interpretation of previous and new measurements of carbon fluxes preferably involving an element of modelling.


Methodology: The ongoing research in carbon cycling at the Zackenberg research station builds on the use of the eddy correlation technique for atmospheric gas fluxes (H2O, CO2 and CH4). In soil science pore air/water sampling is a prominent tool in the analysis of weathering and decomposition of inorganic and organic soil components. It is likely that an element of the techniques form both of the sciences will be appropriate in the current project to improve the modelling at an integrated soil/ecosystem level.


Contact: Thomas Friborg, Institute of Geography, University of Copenhagen (email: [email protected]) and Hanne Petersen (DMU, Afdeling for Arktisk Miljų)