中亚热带森林转换对地表CH_4氧化的影响

Effects of Forest Conversion on CH_4 Oxidation Rates in Mid-Subtropics

利用静态箱-气相色谱法对中亚热带常绿阔叶天然林与杉木人工林地表CH4氧化速率进行17个月的定位观测研究。结果表明:在观测期间(2009-04—2010-08),天然林与人工林均表现为大气CH4汇,天然林与杉木人工林地表CH4年均氧化速率分别为32.01和25.31μg·m-2h-1,天然林地表CH4氧化速率为10.83～75.02μg·m-2h-1,人工林地表CH4氧化速率为7.66～46.40μg·m-2h-1;地表CH4氧化速率受土壤温度、含水量及其交互作用的影响,土壤体积含水量显著影响地表CH4氧化速率,而土壤温度对地表CH4氧化速率的影响则因土壤体积含水量和土壤深度而异。

In this study, the forest soil CH4 oxidation rates were measured for consecutive 17 months（2009-04—2010-08） using static chamber and gas chromatography techniques. The results showed that soils of both natural forest and plantation were sinks for atmosphere CH4. CH4 oxidation rates varied from 10.83 μg·m-2h-1 to 75.02 μg·m-2h-1 for natural forest and from 7.66 to 46.40 μg·m-2h-1 for plantation during the observation period, and mean annual CH4 oxidation rates in natural and plantation forest soils were 32.01 and 25.31 μg·m-2h-1, respectively. CH4 oxidation rate was regulated not only by soil temperature, but also by soil volumetric water content and their interaction. While the soil volumetric water content significantly affected CH4 oxidation rates, the effect of soil temperature was dependent on soil volumetric water content and soil depth.