Removal of methyl chloroform in a coastal salt marsh of eastern China

The atmospheric burden of methyl chloroform (CH3CCl3) is still considerable due to its long atmospheric lifetime, although CH3CCl3 emissions have declined considerably since it was included into the Montreal Protocol. Moreover, CH3CCl3 emissions are used to estimate hydroxyl radical (OH) levels, trends, and hemispheric distributions, and thus the mass balance of the trace gas in the atmosphere is critical for characterizing OH concentrations. Salt marshes may be a potential sink for CH3CCl3 due to its anoxic environment and abundant organic matter in sediments. In this study, seasonal dynamics of CH3CCl3 fluxes were measured using static flux chambers from April 2004 to January 2005, along an elevational gradient of a coastal salt marsh in eastern China. To estimate the contribution of higher plants to the gas flux, plant aboveground biomass was experimentally harvested and the flux difference between the treatment and the intact was examined. In addition, the flux was analyzed in relation to soil and weather conditions.