How soil frost affects greenhouse gas emissions from Arctic soils
Soil frost is a nearly universal process in the Arctic. In a recent dissertation by doctoral student Marina Becher at Umeå University, it is shown that the frequency and extent of soil frost is important for the release of the greenhouse gas carbon dioxide from arctic soil.
Soil in the Arctic has for thousands of years gathered large quantities of decomposed organic matter due to the decomposition being slow at the low temperatures in the region. As temperatures in the Arctic are increasing, there is a growing concern that the organic matter stored in the ground will be decomposed and released as carbon dioxide. Such a process would contribute to the ongoing increase in this greenhouse gas in the atmosphere.
So far, predictions of future carbon dioxide emission from arctic soil have not taken into account how soil frost processes affect greenhouse gas emissions. Marina Becher at the Department of Ecology and Environmental Science shows in her dissertation that temperature is not the only important factor for the amount of greenhouse gas being released from the soil. She provides results that imply that the release of carbon dioxide will also be affected by the changes in soil frost processes.
An intriguing result of Becher's studies is that soil affected by severe soil frost seems to be acting as a significant source of carbon dioxide in the Swedish mountains.
"I measured the fluxes of carbon dioxide for one year in fifteen various sites in the mountainous area of Abisko in northern Sweden. I found that all these locations released more carbon dioxide than what could be taken up and stored in local plants" says Marina Becher.
Frosty soil pattern in soil image via Shutterstock.
Read more at ScienceDaily.