Research of Greenhouse Gases (CH4 and CO2) Emission Flux in Baiyangdian Wetland

CH₄ and CO₂ are important greenhouse gases, playing a very important role in greenhouse effect. In order to estimate the current situation of source and sink of main greenhouse gases in Baiyangdian wetland and evaluate the influences of wetland system to the greenhouse effect of North China, static closed chamber-gas chromatogram method was adopted to study the space-time variation characteristics of N₂O, CH₄, and CO₂ emission fluxes in Baiyangdian wetland. The analysis results indicate: the lake wetland which was abundant in organic matters and nutritive salt was an important greenhouse gases emission source. During one year of observation, it was found out that the fluxes of N₂O, CH₄, and CO₂ of Baiyangdian wetland posses a very high time variability, with the range of variation being-0.08~0.33 mg·m^-2·h^-1, -5.40~328.65 mg·m^-2·h^-1 and -814.06~2934.93 mg·m^-2·h^-1. The emission fluxes of N₂O, CH4, and CO2 reaches to maximum in summer, respectively being 62.09%, 92.15% and 87.04% of the annual total emission flux, The lakeside was a core area of N₂O, CH₄ emission, with annual average emission flux respectively reaching up to 0.11 mg·m^-2·h^-1 and 40.86 mg·m^-2·h^-1. Although the main emission area of CO₂ was land, the emission flux of lakeside, with annual average emission flux being 692.35 mg·m^-2·h^-1, was also very high, ranking only second to land, the lakeside area of Baiyangdian wetland was only 12.60% of the whole lake wetland area, but the emission loads of N₂O, CH₄, and CO₂ were respectively 26.51%, 43.96% and 23.76% of the total emission load, which explains that the lakeside wa- leading the greenhouse gases emission of Baiyangdian wetland.