In this study, we analyzed seasonal variations in carbon dioxide fluxes, concentrations, and soil temperatures over three years in unvegetated tidal flats in the Beolgyo area. We also investigated the correlations between carbon dioxide fluxes and influencing factors. The average carbon dioxide flux was positive in summer and autumn but negative in winter and spring. A positive correlation was observed between carbon dioxide flux and soil temperature in spring whereas a negative correlation was noted in summer. In summer and autumn, as the soil temperature increased, the carbon dioxide flux decreased. In contrast, in spring and winter, as the soil temperature decreased, the carbon dioxide flux increased. Overall, this study reveals the significant influence of soil temperatures on carbon dioxide fluxes between the surface layer of the tidal flat and atmosphere.

In order to analyze the sensitivity of carbon dioxide flux by soil temperature in the grassplot, carbon dioxide flux and soil temperature were observed 24 times from March, 2010 to March, 2011 at nine sites in the grassplot. The average of CO2 in the grassplot is 2.2~36.7℃, the highest in August, the lowest in January, and the average of carbon dioxide flux is 12~1479 mgCO2·m-2·hr-1, and the carbon dioxide emission from the grassplot to the atmosphere was 10 times higher in summer than in winter. The temperature response coefficient estimated by the exponential function of carbon dioxide flux according to soil temperature was ranged from 0.1065 to 0.1274, and the increase tendency of CO2 flux with soil temperature was linear at 0~2 0℃and exponential at 20~40℃. The Q10 values for each of nine observation sites on the grassplot was in the range of 2.901 ~ 3.575, and the Q10 value using the total data observed in the lawn was estimated to be 3.374. In the homogeneous grassplot area, the average of Q10 values by observation point and the Q10 value by the total data were estimated similarly.