青海湖北部土壤CO_2浓度变化研究  

A study on change of soil CO_2 concentration in north Qinghai Lake

作　　者：赵景波[1,2] 李岩[1] 曹军骥[2] 郁科科[1] 

机构地区：[1]陕西师范大学旅游与环境学院,西安710062 [2]中国科学院地球环境研究所黄土与第四纪地质国家重点实验室,西安710075

出　　处：《地球环境学报》2011年第1期278-284,共7页Journal of Earth Environment

基　　金：国家科技支撑计划(2007BAC30B01)

摘　　要：利用红外CO_2监测仪对青海湖地区哈尔盖附近不同植被、不同深度条件下的土壤CO_2浓度进行了多次昼夜观测。观测结果表明,在年平均温度1℃左右的高寒青海湖地区,从早8:00到次日早8:00土壤CO_2浓度具有从低到高再到低的昼夜变化规律,这种变化特点与昼夜温度变化基本一致。在土壤夜间最低温度为0%和更高地区,土壤CO_2浓度的这种昼夜变化规律具有普遍性。该区白天12小时土壤CO_2浓度略高于夜间12小时,但比低海拔地区白天与夜间的浓度差异小。在土壤1 m深度范围内CO_2浓度随深度增加而增加。土壤C02浓度明显高于地面之上100 cm空气CO_2浓度,显示在温度较高季节土壤在向大气释放CO_2。在高寒干旱草原粉砂土分布区,只要土壤温度接近零度或零度以上,土壤CO_2浓度就会高于空气CO_2浓度,土壤CO_2就会向空气中排放。高寒干旱区影响土壤CO_2浓度的最主要的因素是温度,该地Q_(10)平均值为2.81,表明温度对青海湖草原土壤CO_2浓度的影响比对低海拔草原CO_2浓度的影响更大。The CO2 concentration at different vegetation and different depth of soil CO2 concentration of day and night at Haergai town is observed by utilizing infrared CO2 monitor. The results show that from 8：00 am to 8：00 am of the next day, the soil CO2 concentration is from low to high then to low at the cold and alpine area whose average temperature is about 1 ℃ . The diurnal variation law of soil CO2 concentration has universality at the area of minimum night temperature above 0 ℃ . The diurnal variation law of CO2 concentration is consistent with the diurnal variation of temperature but lags for about 2 hours. The day soil CO2 concentration was slightly higher than the night. The difference of CO2 concentration between day and night is small at low altitude. The soil CO2 concentrations increase with depth within 100 cm. The CO2 concentration of soil was significantly higher than the air of 100 cm above ground, which shows that the soil released CO2 into the atmosphere in high temperature seasons. The soil CO2 concentration will release into air as long as the soil temperature close to 0℃ or above 0℃ at cold and arid grassland. The most important affecting factor of soil CO2 concentration is temperature. The average value of Q10 is 2.81, which shows that the temperature affects on grassland soil CO2 concentration at high altitude greater than the low altitude.

关 键 词：青海湖地区 土壤CO2浓度 昼夜变化规律 土壤CO2释放 温度 

分 类 号：S154.1[农业科学—土壤学]