As the import component of ecosystem carbon and nitrogen cycling, soil CO2, CH4 and N2O fluxes have been received long term attention. However, due to the technical limitation, such fluxes are usually measured through static chamber-gas chromatography method, which is labeled with labor-consuming and discontinuous measurement, and is difficult to provide more support to understand the responses of soil processes to the rapid changing environment. In this study, we used a new observation system which combined with rapid gas analyzers (907-0010 and 907-0014, Los Gatos Research) to measure the soil CO2, CH4 and N2O fluxes of a temperate mixed forest in situ and continuously, and to investigate the effect of environmental changes on soil GHGs fluxes.
Results/Conclusions
With one-year preliminary measurement, we found that the soil CO2 efflux was generally related exponentially with the variation of soil temperature, while such relationship was varied in different seasons. Soil CH4 flux was negative with the variation of soil temperature, and soil appeared as an obvious CH4 sink, especially during the growing season. As for soil N2O flux, on the one hand, no apparent seasonal variation of soil N2O was observed, and the magnitude of soil N2O flux was generally weakly compared to that of CO2 and CH4 fluxes. On the other hand, a rush-out of soil N2O flux was observed during the beginning of spring. Further analyze indicated that the average efflux was increased more than 3 times, and the maximum efflux intensity was more than 5.0 nmol m-2 s-1 which was nearly 10 times than other period during the first ten-day when soil surface temperature exceeded 0oC.