N_2O and CH_4 fluxes in an island forestin wetland, Sanjiang Plain

N_2O and CH_4 fluxes from an island forest floor in wetland were observed with static-chamber and GC methods from June 1 to September 28 of 2003 in Sanjiang Plain. This paper analysed the seasonal characteristic of N_2O and CH4 fluxes from island forest floor in wetland and primarily discussed the relationships between fluxes of two greenhouse gases and temperature and soil water content. CH_4 and N_2O fluxes of island forest showed an obvious alternation of positive and negative values with the range of -560.45 to 706.35 μg·m-2·h-1 and -28.87 to 43.59 μg·m-2·h-1, respectively, and the seasonal mean was 41.88 μg·m-2·h-1 for CH4and 11.56 μg·m-2·h-1 for N_2O. The results showed that the soil of island forest in wetland is a sink of CH_4 and N_2O. Correlation analysis showed that there is a weak correlation between emissions of CH_4 (0.566, n=8) and N2O (0.443, n=12) and the temperature in chamber. Soil water content is an important factor effecting the consumption-emission relation of CH_4 and dry-wet change in soil accelerated N_2O emission from island forest floor.