[1] Methane (CH 4 ) and carbon dioxide (CO 2 ) fluxes on east European tundra wetland ecosystems (67°23 0 N, 63°22 in a 100 day summer period in WF, IF, WL, IL, and HCK, respectively. The losses of carbon in winter accounted for 23.7%, 5.0%, 3.1%, 2.6%, and 2.3% of the net ecosystem production. CH 4 emissions in summer (and winter) were 7.7 (7.8), 6.6 (0.8), 8.2 (0.4), 0.7 (0.3), and 0.1 (0.2) g C m À2 for WF, IF, WL, IL, and HCK, respectively. The modeled annual carbon balance for grouped microsites shows that dry HCKs were carbon sources À7.5 g C yr À1 while flarks and lawns were carbon sinks ranging from 2.2 to 35.9 g C yr À1 . The results show the importance of WT and vegetation composition on annual flux dynamics in a tundra wetland. CH 4 emissions from arctic peatlands seem to be sensitive to changes in the WT.INDEX TERMS: 1615 Global Change: Biogeochemical processes (4805); KEYWORDS: carbon, Arctic, tundra, Russia, carbon balance, global change Citation: Heikkinen, J. E. P., V. Elsakov, and P. J. Martikainen, Carbon dioxide and methane dynamics and annual carbon balance in tundra wetland in NE Europe, Russia, Global Biogeochem.