西安南郊不同深度土壤CO_2浓度变化研究

利用红外CO2监测仪对西安南郊不同深度条件下的土壤CO2浓度进行了多次昼夜观测。观测结果表明:在一昼夜内土壤CO2浓度具有从低到高再到低的变化规律,这种变化特点与昼夜温度变化基本一致;土壤CO2浓度从总体来看具有白天高,夜间低,夏季高,秋季低的特点;浅层土壤CO2浓度昼夜变化幅度明显大于深层土壤CO2浓度变化幅度;在厚层黄土的150cm深度范围内,土壤CO2浓度随着深度的增加而增加,在150~600cm深度范围内CO2浓度基本恒定,显示出与薄层土CO2浓度变化明显不同。

Research on CO2 Density Changes in Different Depth of the Soil in the South Suburb of Xi'an

Use the infrared monitor of CO_(2)to test the CO_(2) concentration of the different depth soil in the south suburb of Xi'an round the clockmany times.The results show: The soil CO_(2) concentration changed from low to high and then tolowfrom the morning to the next morning.The change of soil CO_(2) concentration coincided with the temperature change,but the change of the former was later than that of the latter.The soil CO_(2) concentration was higher in day than in night;The soil CO_(2) concentration was higher in summerthan in autumn.The temperature was the main factor determining the change law of the soil CO_(2) concentration.The soil CO_(2) concentration of the shallow layer changed greater obviously than that of deep layer during 24h.The soil CO_(2) concentration grew with the depth of layer till it reached a steady amount in 150cm,which was different from the result of the thin layer.