Abstract: In November 2008-October 2009, a field research by the method of static chamber-gas chromatography was conducted on the spatiotemporal pattern of methane (CH₄) emission from two riparian wetlands (constructed and natural) in the Wilma H. Schiermeier Olentangy River Wetland Research Park in Columbus, Ohio, USA, with the effects of soil temperature, carbon content, hydrological condition, and vegetation on the CH₄ emission approached. Both of the wetlands had an obvious seasonal variation of CH₄ flux, and the CH₄ emission from natural wetland was significantly higher than that from constructed wetland (P<0.05), being 114 and 68 g CH₄-C·m^-2·a^-1, respectively, possibly due to the higher cumulative productivity in natural wetland. For the two wetlands, the CH₄ emission was higher in deep water zone than in transition zone, and the median value (average) was 4.7 (59.9 mg·m^-2·h^-1) and 0.09 (1.17 mg·m^-2·h^-1), respectively (P<0.01). Intermittent flooded area produced lesser methane than permanently inundated area, and soil temperature and organic carbon content had definite effects on the CH₄emission. It was suggested that to configure proper vegetation and proper hydrological conditions in riparian wetland and to implement proper management could effectively reduce the CH₄ emission from the wetland.

Key words: Forest landscape boundary, Changbai Mountain, GIS, RS