4.4. Conclusion
This study explored the process of deep soil carbon mineralization and diffusion to the soil-atmosphere interface, as well as the driving factors. We extended the study area of ​​soil CO2 flux from shallow layer (0-80 cm) to deep layer (80-200 cm),and soil CO2 fluxes were measured calculated at each profile. The results showed that the CO2 flux has a vertical decline and seasonal double-peak change trend; the contribute of CO2 flux at deep layers to the soil-atmosphere interface is stable, ranging from 21.81% to 24.42%; The CO2emissions at each profile were drived by soil temperature ,moisture, and soil organic carbon. It would cause more intense CO2emissions in deep layers than the shallow layer after being stimulated by temperature disturbance. Soil moisture had strong influence on the CO2 flux at the near-surface and deep layers, but weaker at the layers of 20cm and 80cm. The soil organic carbon had a certain reverse feedback effect on the CO2 flux at the near-surface and deep layers. To evaluate accuratly soil CO2 emissions and clarify the dynamic change mechanism of deep soil carbon pools, it was necessary to develop a new T & M & C prediction model based on the traditional two-factor empirical model of temperature and moisture, taking into account the role of soil organic carbon substrates.