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

From early July to late September 2008, we studied CO2 emissions from 4 different stands in newly created marshes of the Pengxi River, using static opaque chamber-GC techniques. The results showed high spatial variation of CO2 emissions among the four stands. The greatest CO2 emission (627.8 ± 335.9 mg·m-2·h-1) was observed in the Scirpus triqueter stand. The smallest CO2 emission (450.4 ± 271.5 mg·m-2·h-1) was observed in the Juncus amuricus stand.Standing water depths and above-ground biomass were important factors in explaining these spatial variations in CO2 emissions. We also found a typical seasonal variation of CO2 emissions in this area, with maximal emissions ranging from mid-July to mid-August. The seasonality of CO2 emissions in the newly created marshes was found to be closely related to water temperature and soil temperature (r = 0.577, 0. 557 (5 cm),p < 0.001).