Dynamic Changes and Driving Mechanism of Soil CO_2 Emission Fluxes of Different Land Use in Western Jilin Province

摘要

Using GXH-3051A infrared analyzer, the paper monitored the seasonal variations of soil CO_2 emission fluxes of four land use types with the dynamic closed chamber method in western Jilin Province and analyzed the driving mechanism. The result shows that the soil dynamic changes of paddy field, dry farmland, grassland and saline-alkali land present multi-peak curves, but the means of emission fluxes exist large differences. Temperature and moisture are the main factors leading to the differences of CO_2 emission fluxes. There is a significant exponential relationship between the dynamic changes of CO_2 emission fluxes and soil temperature, but the exponential relationship is poor between the dynamic changes of CO_2 emission flux and moisture. Hydrothermal two-factor composite model can explain the dynamic changes of CO_2 emission fluxes well, which illustrates the change of CO_2 emission fluxes of 65.47% of paddy soil, 76.25% of dry farmland, 82.17% of grassland and 57.62% of saline-alkali soil.