Land atmosphere exchange of carbon dioxide and methane in a high-Arctic wet tundra ecosystem
Approximately 50% of the soil organic carbon is today stored in the northern permafrost regions. This is more carbon than is stored in the entire atmosphere and all vegetation across the world, added together. Arctic areas are fragile to climate change, and large effects of the climate warming are already seen. The focus of this project is to study the exchange of carbon between the land and the atmosphere in a high Arctic wet tundra ecosystem in North Eastern Greenland.
By combining field measurements of photosynthesis with satellite images, we have seen that there has been a strong increase in photosynthesis by the vegetation in this high Arctic wet tundra ecosystem 1992-2008. The increase in photosynthesis came with a strong increase in CO2 concentration and air temperature. Possibly, indicating that these were the main factors resulting in the increased photosynthesis.
In a second project, we related field measured methane emissions to climatic variables, to see what factors that affect the methane emissions in high Arctic areas. During summer, it could be seen that methane emissions were closely related to soil temperature. Between years, it was closely related to amount of soil water. The measured methane emissions were also combined with satellite images, to see if there have been any changes in the methane emissions 1997-2009. There were large differences in methane emissions between years, but no trend 1997-2009 was seen. The differences between the years were explained by interannual variation in wetness of the area.
Julie M. Falk
Mikkel P. Tamstorf
Torben R. Christensen
Contact point: Torben R. Christensen