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.