Chamber CH4 flux observed at taiga-tundra boundary near Chokurdakh in northeastern Siberia during the summer from 2009 to 2013 as well as isotopic compositions of dissolved CH4 and soil incubation experiments

Flux of CH4 emission was observed by the chamber method at the taiga-tundra boundary in the vicinity of Chokurdakh (71 N, 148 E) in northeastern Siberia during the summer from 2009 to 2013. The observation period includes a wetting event with extreme precipitation in 2011. From 2011 on, dissolved CH4 in surface water and soil pore water in wet areas of sphagnum mosses and sedges was analyzed for concentration, delta-13C, and delta-D to discuss fluctuations in the CH4 production and CH4 oxidation processes. In addition, soil incubation experiments under anaerobic and aerobic conditions were conducted to investigate behaviors of isotopic compositions of CH4 in the CH4 production and CH4 oxidation processes and interpret in situ isotopic data. Using the same sampling locations as the anaerobic incubation experiment, phylogenic compositions of methanogenic archaea were analyzed by amplicon sequencing of 16S rRNA gene to discuss CH4 production pathways. This data set shows interannual variations in CH4 flux before and after the wetting event and those in CH4 production and oxidation processes after the wetting event.