CHENG Jian-zhong1, LEE Xin-qing1*, ZHOU Zhi-hong1,2, WANG Bing1, CHENG Hong-guang1, XING Ying1,2，TANG Yuan1,2
(1. State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China;
2. Graduate University of the Chinese Academy of Sciences, Beijing 100049, China)
Abstract：Seasonal variations in the concentrations of soil air CO2 and surface CO2 fluxes under different land uses were studied in the karst regions of Guizhou by GC technique for one year. The results showed that the seasonal variation regularities of soil CO2 concentrations and surface CO2 fluxes were very obvious, i.e., increasing from spring to summer and decreasing from autumn to winter in response to temperature and precipitation changes in this region. Subsurface CO2 concentrations and surface CO2 fluxes under different land uses were significantly positively correlated with air temperature and soil temperature at different depths. Soil moisture (WFPS) influenced soil CO2 concentrations and surface fluxes to some extent, but in almost all fields, there was no obvious correlation between them. The correlation analysis results showed there was a significant and positive relationship between soil CO2 concentrations and surface CO2 fluxes, suggesting surface CO2 fluxes strongly depended upon the accumulation and distribution of CO2 concentrations in the soil profile.
Key words: soil CO2 concentration; surface CO2 flux; seasonal variation; temperature and moisture; karst region
EARTH AND ENVIRONMENT Vol. 39, No.2, Tot No.283, 2011, Page 196-202
