西安地区土壤CO2 释放量和释放规律

根据碱溶液吸收法,对西安地区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,西安地区各月份土壤CO2释放量在一昼夜内具有明显的变化,从当日上午到次日上午,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左右,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和放量的增加和减少,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12h释放量大于白天12h释放量。

The release amount and its change law of CO2 from soils in Xi'an area

On the basis of the principle of which CO2 is absorbed by the solution of NaOH, the release amount of CO2 in soils under different vegetation was observed round the clock. The material shows that the release amount of CO2 from soils in Xi'an area changed clearly in 24 hours in months. The release amount changed from low to high and then to low from the morning to the next morning. The change of the release amount of CO2 was same that as the temperature, but the change of the former was about 4-6 hours later than that of the latter. The temperature was main factor determining change law of release amount of CO2 from soils and its rising and falling bring out the increase and decrease of release amount of CO2. The release amount of CO2 from soils was changing along with different vegetation. The forestry land was greater than grassland and the grassland was greater than the bare land in the release amount. The release amount was greater in day than in night.