Thawing sub-arctic permafrost:Effects on vegetation and methane emissions

• Published in: Geophysical Research Letters
• Main Authors: Christensen, TR, Johansson, TR, Akerman, HJ, Mastepanov, M, Malmer, N, Friborg, T, Crill, P, Svensson, BH
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2004
• Subjects: TRACE GAS-EXCHANGE; NORTHERN PEATLAND; BOREAL PEATLAND; VASCULAR PLANTS; CO2 EXCHANGE; CH4 FLUXES; MIRE; ECOSYSTEM; WETLANDS; CLIMATE; Arctic; permafrost; Subarctic
• Online Access: https://pure.au.dk/portal/en/publications/c720a7d4-4875-43a8-aa2b-a36b2ad0f208; https://doi.org/10.1029/2003GL018680

Ecosystems along the 0degreesC mean annual isotherm are arguably among the most sensitive to changing climate and mires in these regions emit significant amounts of the important greenhouse gas methane (CH4) to the atmosphere. These CH4 emissions are intimately related to temperature and hydrology, and alterations in permafrost coverage, which affect both of those, could have dramatic impacts on the emissions. Using a variety of data and information sources from the same region in subarctic Sweden we show that mire ecosystems are subject to dramatic recent changes in the distribution of permafrost and vegetation. These changes are most likely caused by a warming, which has been observed during recent decades. A detailed study of one mire show that the permafrost and vegetation changes have been associated with increases in landscape scale CH4 emissions in the range of 22-66% over the period 1970 to 2000.