[Effects of elevated ozone concentration on CO2 emission from soil-winter wheat system]

To investigate the impact of elevated ozone (O3) on CO2 emission from soil-winter wheat system, outdoor experiments with simulating elevated O3 concentration were conducted, and static dark chamber-gas chromatograph method was used to measure CO2 emission fluxes. Results indicated that the elevated O3 did not change the seasonal pattern of CO2 emissions from soil-winter wheat system, but significantly decreased CO2 emission fluxes during turning-green stage and elongation-pregnant stage. From heading to maturity, CO2 emission fluxes were not found to be significant difference under 100 nL x L(-1) O3 treatment compared with the control, while 150 nL x L(-1) O3 treatment significantly declined CO2 emission fluxes. Significant relationships were found between respiration rate and air temperature under the control, 100 nL x L(-1) and 150 nL x L(-1) O3 treatment, and the fitting equation determined coefficients R2 were 0.139, 0.513 and 0.211, respectively. In addition, the Q10 (temperature sensitivity coefficients) for soil-winter wheat system's respiration were 1.13, 1.58 and 1.21, respectively. The results of this study suggested that elevated O3 could reduce CO2 emissions from agroecosystem.