Methan Dynamics in an Arctic Wetland:Effects of Vegetation and Climate Manipulations

• Main Author: Nielsen, Cecilie Skov
• Format: Book
• Language: English
• Published: Department of Geosciences and Natural Resource Management, Faculty of Science, University of Copenhagen 2016
• Subjects: Arctic; Greenland; Carex aquatilis; Eriophorum; permafrost
• Online Access: https://curis.ku.dk/portal/da/publications/methan-dynamics-in-an-arctic-wetland(ecc6f69c-52e0-4fd6-91f2-aeb0da3b9120).html; https://soeg.kb.dk/permalink/45KBDK_KGL/fbp0ps/alma99122734947505763

Rising temperatures in the Arctic have the potential to increase methane (CH4) emissions from arctic wetlands due to increased decomposition, changes in vegetation cover, and increased substrate input from vegetation and thawing permafrost. The effects of warming and changes in vegetation cover on CH4 emissions are however still largely unknown for the Arctic. Many wetlands plants such as sedges can increase CH4 emissions by transporting the CH4 through internal air tissue. However, at the same time the plants can reduce the CH4 emissions by transporting oxygen to the rhizosphere where it can be used to oxidize CH4. The over all effect of the presence of sedges on the CH4 budget is unknown for most arctic species. Here the effects of warming and changes in plant cover on CH4 dynamics and emissions in a wetland in Blæsedalen, Disko Island, W. Greenland were investigated. The importance of CH4 oxidation in the rhizosphere of Carex aquatilis ssp. stans and Eriophorum angustifolium was quantified using a 13CH4 tracer. The results showed that rhizospheric CH4 oxidation mediated less than 2% of ecosystem CH4 emissions. No significant effects of warming or shrub removal on ecosystem CH4 emissions were found after one year of treatments suggesting that, regarding CH4 emissions, the wetland is resilient towards a small degree of warming on a short term.