陕西黄土高原中南部土壤CO_2释放量变化研究

A Study on the Flux of CO_2 Release in the Middle and South of the Plateau of Shaanxi

本文根据 NaOH溶液吸收CO_2的方法 ,对陕西黄土高原中南部4个观测点的土壤CO_2释放量时行了昼夜观测。观测结果表明 ,不同地区、不同气候和不同土质土壤CO_2释放量存在差异 ,冷干地区较暖湿地区土壤CO_2释放量少,凉季较暖季土壤CO_2释放量少;粘性硬质土较松散黄土CO_2 释放量少。长武、洛川、西安南郊土壤CO_2释放量变化再次证明 ,在厚层黄土发育的地区 ,土壤CO_2释放量变化相对于大气温度变化具有滞后性,从当日早晨至次日早晨,CO_2释放量具有由低变高再变低的普遍规律。

By means of CO_2 absorption by NaOH solution, the flux of CO_2 release in four research areas was observed in the middle south of Loess Plateau in Shaanxi. Results show that there are differences amang flux of CO_2 released in different areas, different climate and different geological conditions. The release flux is lower in cool and arid area than that in warm and moist area, and it is lower in cool season than that in warm season; and it is also lower in hard soil than that in loose soil. The flux of CO_2 release in Chanwu, Luochuan and the south of Xi'an area proved again that the flux of CO_2 release from soil is about 4~6 hours later than that of air temperature change, and the release flux changes from low to high and then to low from this morning to the next, which is general regularity of the change of release flux of CO_2 on thick loess layer.