黔中岩溶地区草地下土壤CO_2含量的变化特征

Variation of CO_2 Content in the Karst Meadow Soil of Central Part of Qianzhong Province

全球碳循环中,CO_2的未知汇可能是陆地生态系统中某一部分,如土壤。土壤中CO_2的含量是大气的几倍至近百倍,它的吸收与释放将影响大气中的CO_2浓度。岩溶地区占全球陆地面积的1/15。对典型的岩溶地区——黔中某地土壤的CO_2进行了四季及昼夜的采样测定,结果表明,该地地表大气的CO_2含量具有季节变化的特征。土壤气中的CO_2浓度为大气CO_2浓度的几倍至一百多倍;自地表向下,随着土壤深度的增大,CO_2浓度升高。土壤CO_2含量的季节变化及昼夜变化,与土壤中CO_2来源和温度等因子变化有关。

In the global carbon cycle, the unknown summation of CO2 may be a part of land ecosystem, such as soil. The content of CO2 in soil is tens to near hundred fold than in atmosphere, whose absorption and emission will affect the concentration of CO2 in atmosphere. Karst area occupies 1/5 of the total global land area. For the typical karst area in the central part of Guizhou Province, monitoring on soil CO2 content has been conducted for four seasons day and night. The result showed that the C02 content in the land surface atmosphere occurred seasonal variation, and CO2 concentration in soil was several-fold to more than hundred-fold; from the land surface downwards, CO2 concentration increased with the increment of soil depth. The concentration of soil CO2 occurred seasonal variation and day-night variation, which related to the source of CO2 in soil and atmosphere.