Abstract:

Wetland, as one of the most important components of terrestrial ecosystems, was recognized as the important carbon storage. In decades, the cultivation of wetland made the soil carbon storage lose seriously. CO2 emission of wetland had amounted to 1/10 of the total world emission. To study the impact of the change of land use on soil respiration will help to understand wetland carbon cycle, to calculate carbon budget, and then, to put forward the countermeasures to mitigate the carbon emission. By using LI8100A dynamic closed chamber survey, we analyzed soil respiration of three different land uses, which are uncultivated land, fallow land and crop land, in riparian zone of Zhalong wetland during midMay to midAugust in 2011. The results indicated that the soil respiration rate is 4.44±1.84 μmol·m-2·s-1(uncultivated land), 5.16±3.43 μmol·m-2·s-1(fallow land), and 3.70±2.34 μmol·m-2·s-1(crop land), respectively. The ratio of day time respiration to night time respiration is 6∶4. The main factors impacting on soil respiration are air temperature, moisture, and soil temperature. Q10, the temperature sensitivity of respiration, decreases in the order of uncultivated land (1.86)＞fallow land (1.65)＞crop land (1.56).

Key words: Zhalong wetland, land use, soil respiration, Q10