未来气候变化对旱田生态系统N_2O释放的潜在影响

The potential effects of climate changes in future on N_2O emissions from agricultural soils

反硝化-分解作用模型（DNDC）能较好地拟合贵州省玉米—油菜轮作田、大豆—冬小麦轮作田和休耕地的N2O释放通量及其影响因子季节变化模式，采用DNDC模型定量探讨了未来气温、降雨量和降雨中无机N浓度变化对亚热带旱田生态系统N2O释放的潜在影啊．结果表明，除大亚外，其它作物和休耕地土壤N2O释放通量对气温变化接近于正响应；玉米地、大豆地和体耕地（对应于玉米生长期）土壤N2O释放通量对降雨量的变化也接近于正响应；降雨中无机氮浓度的变化对3块实验田NO2释放通量影响最大．

Based on the success of DNDC model elucidating N2O emissions and its influencing factors from a com-rape rotation a soybean-winter wheat rotation, and a fallow land in Guizhou Province, DNDC model was used to assess the potential effects of variations in air temperature, precipitation, NO3- and NH4+ concentrations in precipitation in future on N2O emissions from sub-tropical agricultural soils. Results indicated that N2O emissions from fallow land and croplands except soybean were positive relation to variations in air temperature, N2O emissions from corn land, soybean land and fallow land (corresponding to corn growing period) were also positive relation to variations in precipitation, and varying the in-organic N concentration in precipitation produced the largest effect on N2O emissions.