摘要
对石林地区两个研究点土下20、40和60cm土壤CO2浓度和土壤CO2排放量的昼夜变化进行的研究表明二者之间具有一定的正相关关系,因此土壤CO2排放量除受环境因子影响之外,还受土壤CO2浓度所控制。土壤CO2浓度和土壤CO2排放量之间的相关关系可以用来解释土壤有机碳含量及温度对土壤CO2排放量的影响,即土壤有机碳含量高和温度升高是通过影响土壤空气中CO2的形成速率,导致土壤CO2浓度升高,从而促进土壤CO2的排放。
Diurnal variation of soil CO2 concentration and flux of red soil and their relationship were studied in June of 2002 in Shilin national park,Yunnan provice. Study shows that in different depth, soil CO2 shows fluctuation during 24 hours. From 18:00 to 22:00, concentration of soil CO2 decreases (for example, at subsoil 20cm, soil CO2 concentration decreases from 0.48% at 18:00 to 0.43% at 22:00). From 22:00 o'clock to next 6:00 o'clock, soil CO2 concentration shows a minor fluctuation, and reaches the minimum at 6:00 o'clock. During daytime, from 6:00 to 18:00, soil CO2 concentration increases steadily and at 16:00 o'clock, it reaches the maximum of the whole day. Then it begins to fall down. In site A, soil CO2 concentration increases with soil depth. But it is a different case in site A' because of the disruption of the soil, which doesn't shows the same variation. Sometimes soil CO2 concentration at 20cm depth is greater than that of at 60cm depth. Study result also shows that soil CO2 flux coincides with soil CO2 concentration at 20cm, 40cm and 60cm. Soil CO2 concentration and flux is higher during daytime than that of night. The positive relationship between soil CO2 content and soil CO2 flux gives good explanation to the relationship between the soil organic carbon content, temperature with soil CO2 flux. Soil CO2 concentration in different soil depth increase with higher production of soil CO2 because of higher soil organic carbon content and increasing temperature. As this study shows, Soil CO2 flux will increase when soil CO2 concentration increases.
出处
《地理科学进展》
CSCD
北大核心
2003年第2期170-176,共7页
Progress in Geography
基金
国家自然科学基金(90202017
410071017)
石林研究基金(199903)资助