title: Dynamics of methane emissions from a freshwater marsh of northeast China.
abstract: In this paper, CH(4) flux was measured from Nov. 2002 to Oct. 2005, to estimate CH(4) emissions in winter and during freeze-thaw period, and interannual variation in CH(4) emissions in freshwater marsh in northeast China. The results showed that there was an obvious CH(4) emission (0.1-2.3 mg m(-2) h(-1)) in the freshwater marsh in winter. Flux of CH(4) in winter (November to March the next year) was about 3.8%, 5.5%, and 2.2% of the whole year in 2003, 2004, and 2005, respectively. Emission of CH(4) significantly increased during the freeze-thaw period (April-June), and was about 30.8%, 20.9%, and 20.6% of the whole year in 2003, 2004, and 2005, respectively. Standing water depth greatly governed interannual variation of CH(4) emissions from marshes during the thaw-freeze period. Interannual variation of CH(4) emissions was significant during the growing season (p<0.05). Standing water depth during April to June was a primary factor, which affected the interannual variation of CH(4) flux during the growing season. Precipitation during the preceding non-growing season affected CH(4) emission indirectly via standing water depth.
authors.affiliation: Northeast Institute of Geography and Agroecology, Chinese Academic Science, Changchun Jilin, 130012, China.
authors.forename: Wenyan
authors.initials: W
authors.lastname: Yang
authors.forename: Changchun
authors.initials: C
authors.lastname: Song
authors.forename: Jinbo
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D002681:China; D004784:Environmental Monitoring; D005618:Fresh Water / Q000737:chemistry*; D008697:Methane / Q000032:analysis*; D012621:Seasons; D053833:Wetlands
chemical_list: D000393:Air Pollutants; D008697:Methane