西安南郊和陕北长武土壤CO_2释放量研究

A STUDY ON RELEASE FLUX OF CO_2 IN SOUTHERN SUBURB OF XI'AN AND CHANGWU OF NORTHERN SHAANXI

本文根据NaOH溶液吸收CO2的方法,对西安南郊和陕北长武地区土壤CO2释放量进行了昼夜观测。观测结果表明,不同地区土壤CO2释放量存在差异,气候偏冷偏干地区土壤CO2释放量较小,气候偏热偏湿地区土壤CO2释放量较大。陕北长武土壤CO2释放量变化再次证明,从当日早晨至次日早晨,CO2释放量具有由低变高再变低的规律;CO2释放量相对于大气温度的日变化具有滞后性,滞后时间为4～6小时;土壤CO2释放量白天较少,夜间较多;CO2释放量变化显示,在土层深厚的地区,土壤微生物夜间活动强度总体应比白天大。

By means of CO2 absorption by NaOH solution, the released flux of CO2 was observed round the clock in southern suburb of Xi'an and Changwu.Results observed show that there is difference of released flux of CO2 in different areas, that released flux is lower in cool and arid area than in warm and moist area. Change of released flux of CO2 proves again that the released flux changes from low to high and then to low from this morning to the next. The change of CO2 released flux from soil is about 4~6 hours later than that of air temperature. The CO2 released flux is less in day than at night, that indicates the activity of microorganisms is stronger at night in thick loess area. 