【摘要】 为探明未经干扰的热带雨林土壤N₂O与CO₂排放对氮沉降的响应，以西双版纳热带雨林为研究对象，设置了对照（CK）和氮添加处理（N）,在持续16个月的连续观测期内，利用静态箱-气相色谱法连续观测土壤N₂O与CO₂通量，同步测定土壤含水量、土壤5 cm温度、土壤铵态氮与硝态氮含量，模拟氮沉降对未经干扰过的热带雨林土壤的N₂O与CO₂排放的影响。结果显示：与CK处理相比，N处理使西双版纳热带雨林土壤N₂O累积排放量增加24.06%,CO₂累积排放量增加10.98%;氮添加带来的增排效应主要集中在氮添加后4个月的显著响应期内，后续非显著响应期内N₂O与CO₂的增排效应并不显著（t=0.98,P>0.05）;在全观测期中，土壤含水量、土壤5 cm温度与土壤N₂O、CO₂排放通量显著正相关（P<0.05）,但是显著响应期内只有CK处理的土壤CO₂排放与土壤5 cm温度显著相关（P<0.05）,其余均无显著相关关系（P>0.05）;氮添加带来的热带雨林土壤N₂O和CO₂的增温潜势（GWP）相当于该生态系统的碳汇能力的103%和104%。研究结果表明，一次氮添加增加了未经干扰的热带雨林土壤的N₂O与CO₂排放，并改变了土壤碳氮排放与环境因子的关系，对区域气候变化形成正反馈效应。更多还原

【Abstract】 In order to explore the response of soil N₂O and CO₂ emissions to nitrogen deposition in undisturbed tropical rain forest, this study took Xishuangbanna tropical rain forest as the research object, and set control（CK）and nitrogen addition treatment（N）.During the continuous observation period lasting 16 months, static opaque chamber and gas chromatography was used to continuously observe soil N₂O and CO₂ fluxes.Soil moisture content, soil temperature at 5 cm were detected synchronously, and contents of soil ammonium nitrogen and nitrate nitrogen contents were measured synchronously to simulate the effect of nitrogen deposition on the N₂O and CO₂ emissions of undisturbed tropical rainforest soil.The results are following: Compared with CK treatment, N treatment increased soil N₂O emission by 24.06% and CO₂ emission by 10.98%in Xishuangbanna tropical rain forest.The increase and emission effects of nitrogen addition were mainly concentrated in the significant response period of 4 months after nitrogen addition, while the increase and emission effects of N₂O and CO₂ were not significant in the non-significant response period（t=0.98,P>0.05）.In the whole observation period, soil water content and soil temperature at 5 cm were significantly positively correlated with soil N₂O and CO₂ emission flux（P<0.05）,but in the significant response period, only soil CO₂ emission under CK treatment was significantly correlated with soil temperature at 5 cm（P<0.05）,and the rest were not significantly correlated（P>0.05）.The warming potential（GWP）of soil N₂O and CO₂ in tropical rain forest caused by nitrogen addition is equivalent to 103% and 104% of the carbon sink capacity of the ecosystem.The results showed that one time single nitrogen addition increased the soil N₂O and CO₂ emissions in undisturbed tropical rainforest soil, and changed the relationship between soil carbon and nitrogen flux emissions and environmental factors, and feedbacked to regional climate change positively.更多还原