A pulse-labeling experiment to determine the contribution of recent plant photosynthates to net methane emission in arctic wet sedge tundra

• DOI: 10.1016/s0038-0717(01)00164-x
• Publication Date: 2002-10-14T21:51:46Z
• Authors: J King
• Keywords: Carex; Carbon fibers

Abstract We conducted a 14 C pulse-labeling experiment under field conditions to estimate the contribution of recent photosynthates to methane (CH 4 ) emission in arctic wet sedge tundra dominated by Carex aquatilis and Eriophorum angustifolium . The average CH 4 emission rate from plant–soil mesocosms in this study was 0.45 g C m −2 d −1 . Carbon assimilated by plants via photosynthesis during pulse-labeling turned over rapidly and appeared as emitted CH 4 within 24 h. Integration of flux measurements made over a 2-week period shows that the contribution of recent photosynthates to mid-season CH 4 emission is relatively low. Less than 1% of the 14 C-labeled carbon dioxide taken up through photosynthesis was emitted as 14 CH 4 during this study.