西安东南部7月份土壤CO_2释放量和释放规律研究

Release amount and its change law of CO_2 from soils on July in Xi′an area

根据碱溶液吸收法 ,对西安东南部地区 7月份不同植被条件下土壤CO2 释放量进行了昼夜观测 .观测资料显示 ,西安东南部地区 7月份土壤CO2 释放量在一昼夜内具有明显变化 ,从当日 9时到次日 9时 ,CO2 释放量表现出由低变高再变低的规律 .土壤CO2 释放量变化与温度变化具有相同的特征 ,但释放量的变化具有滞后性 ,相对于温度的变化滞后 4～ 6h .温度是决定土壤CO2 释放量昼夜变化规律的主要因素 ,它的升高和降低分别造成了土壤CO2 释放量的增加和减少 .不同植被条件下 ,土壤CO2 释放量不同 ,林地释放量大于草地 ,草地释放量大于裸地 ,夜间 1 2h释放量大于白天 1 2h释放量 .

On the basis of the principle of which CO 2 is absorbed by the solution of NaOH. The release amount of CO 2 in soils under different vegetation is observed round the clock. The material shows that the release amount of CO 2 from soils in Xi′an area changes clearly in 24 hours in July. The release amount changes from low to high and then to low from the morning to the next morning. The change of the release amount of CO 2 in same that as the temperature, but the change of the former is about 4～6 hours later than that of the latter. The temperature is main factor determining change law of release amount of CO 2 from soils and its rising and falling bring out the increase and decrease of release amount of CO 2. The release amount of CO 2 from soils is changing along with different vegetation, The forestry land is greater than grassland and the grassland is greater than the bare land in the release amount. The release amount is greater in day than in night.