中文摘要：

通过室外盆栽实验，用静态箱．气相色谱法测定土壤．冬小麦系统的呼吸速率和N2O排放通量，研究了UV-B辐射增强20％对土壤．冬小麦系统的呼吸速率和N2O排放的影响．结果表明，相同的气象条件和田间管理下，UV-B辐射增强处理对呼吸速率和N2O排放的季节变化模式无明显影响．在返青期，UV-B辐射增强显著降低了土壤一冬小麦系统的呼吸速率，但对N2O的排放通量没有产生显著影响；在拔节孕穗期，UV-B辐射增强处理显著降低了土壤-冬小麦系统的呼吸速率和N2O的排放通量；在抽穗．成熟期，UV-B辐射增强处理对土壤．冬小麦系统的呼吸速率和N2O的排放没有显著影响．返青一齐穗期，UV-B增强处理显著降低土壤．冬小麦系统的N2O累积排放量；但从齐穗开始至小麦成熟，UV-B增强处理对土壤一冬小麦系统的N2O累积排放量没有显著影响．

英文摘要：

To investigate the impact of enhanced UV-B radiation on respiration rate and N2O emission from soil-winter wheat system, outdoor pot experiments with simulating 20% supplemental of UV-R were conducted, and static dark chamber-gas chromatograph method were used. Results indicated that the enhanced UV-B radiation did not change the seasonal pattern of respiration rate and N2O emission. Enhanced UV-B radiation declined the rate of soil-winter wheat system＇s respiration but had no significant impact on N2O emission in turning-green stage. While enhanced UV-B radiation declined both respiration rate and the N2O emission in elongation-pregnant stage. From heading to maturity, the respiration rate and N2O emission from soil-winter wheat system were not found to be significantly difference under UV-B radiation compared with ambient conditions. A further analysis suggested that enhanced UV-B radiation declined significantly cumulative amount of N2O from soil- winter wheat system from wheat turning green to full heading stage, while no significant impact occurred from full heading to maturity.