中文摘要：

为研究臭氧浓度升高条件下土壤湿度对农田土壤微生物呼吸温度敏感性的影响,采集经过3个生长季臭氧（100 nL.L-1）熏蒸及对照（CK）处理的农田土壤,在不同土壤湿度下研究土壤微生物呼吸对温度升高的响应规律.结果表明,在土壤湿度适宜的情况下,无论臭氧浓度升高处理还是对照处理中的土壤微生物呼吸均与土壤温度呈现出极显著的指数回归关系.就整个培养试验阶段的平均值而言,CK和100 nL.L-1臭氧处理下的平均土壤呼吸速率分别为0.48和0.33μmol.（m2.s）-1,前者比后者高约45%.臭氧浓度升高显著抑制了土壤微生物呼吸速率,并且显著降低了土壤微生物呼吸的温度敏感性.进一步的结果表明,正常土壤中土壤微生物呼吸的Q10随土壤湿度增加（20%～35%）而下降,而臭氧浓度升高改变了土壤中两者间的这种规律.综合本研究中的结果与以往关于土壤呼吸温度敏感性的研究结果,将Q10与土壤湿度（体积含水量）进行回归分析,可见两者间呈现极显著的二次函数关系,由此可推断其最大Q10值对应的土壤含水量在20%～25%范围内.

英文摘要：

Soil samples of control（CK） and elevated O3 treatments were collected in a cropland where three seasons of O3 fumigation experiments were performed.An incubation experiment was carried out,in order to investigate effects of soil moisture on the temperature sensitivity of soil microbial respiration exposed to elevated ozone concentration and ambient atmosphere.Results indicated that soil microbial respiration increased exponentially with the increase of soil temperature for CK and elevated ozone（100 nL·L-1） treatments when soil had moderate moisture content.During the whole incubation period,mean soil microbial respiration rates for CK and elevated ozone treatments were 0.48 and 0.33 μmol·（m2·s）-1,respectively;the former was~45% higher than the latter,indicating elevated ozone significantly inhibited soil microbial respiration.Elevated ozone also resulted in significantly lower Q10 values compared to CK.Further investigation showed that Q10 of soil microbial respiration decreased significantly with the increase of soil moisture in CK soil,while no such phenomenon was observed in the elevated ozone treatments.Combining the present study and previous investigations about respiratory Q10 in the natural soil produced a quadratic equation,suggesting the optimal moisture within the range of 20%-25% corresponding to the maximal Q10.