摘要
利用静态暗箱法对具有代表性的典型温带草原的羊草群落CO2排放进行了昼夜观测。结果表明,CO2排放通量日变化与气温和地表温度呈明显的正相关关系,相关系数分别为0.7475和0.7604,而与5cm和10cm地温相关性较小,说明在干旱半干旱草原地区气温和地表温度是影响羊草群落CO2排放的关键性因子。研究还发现,羊草群落排放的CO2的近80%来自土壤呼吸、根呼吸和凋落物分解,并且春季露水对羊草草原CO2排放通量日变化特征影响显著,特别是日出前后露水的大量形成,使上午7～8时出现一次CO2排放峰值,而后CO2排放通量变化趋于与气温一致。
Using dark enclosed chamber technique, we measured the daily variation of CO2 flux in Leymus chinensis community in typical temperate steppe.The results showed that CO2 flux from steppe is significantly positively correlated with the soil surface temperature and air temperature,the correlative coefficients between them are 0.7475 and 0.7604,respectively,and almost has no correlation with 5cm and 10cm soil depth temperature.Therefore,soil surface temperature and air temperature play key roles in the flux of CO2 from steppe.Moreover,our results also showed that there are amount of 80% CO2 flux emitted in steppe ecosystem coming from the soil respiration, root respiration and decomposition of litter.And dew has a distinct influence on the daily variation of CO2 flux in spring,especially around sunrise when a lot of dew comes into being.So a maximum of flux of CO2 appears between 7 and 8 A.M.,and then it varies with the air temperature.
出处
《中国草地》
CSCD
2003年第3期9-14,共6页
Grassland of China
基金
中国科学院知识创新重大项目(KZCX1-SW-01-04)
中国科学院地理科学与资源研究所知识创新项目(CX IOG-E01-03-01与CXIOG-A00-06)
国家自然科学基金项目(49971005)等资助
