Study on CO2 Emission from Newly Created Marshes of Pengxi River in the Three Gorges Reservoir

FromearlyJulytolateSeptember2008,westudiedCO2emissionsfrom4differentstandsinnewlycreatedmarshesofthePengxiRiver,usingstaticopaquechamber-GCtechniques.TheresultsshowedhighspatialvariationofCO2emissionsamongthefourstands.ThegreatestCO2emission(627.8±335.9mg？m-2？h-1)wasobservedintheScirpustriqueterstand.ThesmallestCO2emission(450.4±271.5mg？m-2？h-1)wasobservedintheJuncusamuricusstand.Standingwaterdepthsandabove-groundbiomasswereimportantfactorsinexplainingthesespatialvariationsinCO2emissions.WealsofoundatypicalseasonalvariationofCO2emissionsinthisarea,withmaximalemissionsrangingfrommid-Julytomid-August.TheseasonalityofCO2emissionsinthenewlycreatedmarsheswasfoundtobecloselyrelatedtowatertemperatureandsoiltemperature(r=0.577,0.557(5cm),p<0.001).