亚热带森林土壤是重要的N2O气体排放源，而土壤N2O气体的排放对地球环境十分敏感。海拔梯度变化能引起土壤温度、水分分布的差异，进一步影响森林土壤N2O的气体排放通量和途径的差异。为了明确海拔梯度对亚热带森林土壤N2O气体排放机制的影响，本项目以滇中地区哀牢山亚热带森林不同海拔梯度（1000-2600m）的土壤为研究对象。利用气相色谱对森林土壤N2O气体排放通量进行测定，利用稳定同位素技术对森林土壤N2O气体排放途径进行研究；同时，利用分子生物学技术（荧光定量PCR，变形梯度凝胶电泳，高通量测序）对参与N2O气体排放途径的相关土壤微生物丰度和群落结构进行分析。探讨亚热带森林土壤N2O气体排放通量、排放途径、微生物以及土壤环境之间的相互关系，旨在揭示不同海拔梯中的亚热带森林土壤N2O气体排放机制，为发挥亚热带森林生态系统在减缓全球气候变化过程中的重要作用提供科学依据。

Subtropical forest soil is an important source of N2O emissions, and N2O gas emissions from soil are very sensitive to the global environment. Changes of altitude can cause the difference in soil temperature and moisture distribution, it also can affect soil emissions of N2O fluxes and pathways. In order to evaluate the effect of different altitudes on the mechanism of N2O fluxes and pathways in subtropical forest soils, we focus on the subtropical forest soils in Ailao mountain of Yunnan province at different altitudes (from 1000 to 2600 m). Simultaneously, N2O fluxes from subtropical forest soils are measured using gas chromatography methods and the pathways of N2O emissions are analyzed by isotopic methods. In addition, We analyze the abundance and diversity of microbes involved in N2O emissions and pathways in subtropical forest soils using molecular biology techniques (fluorescence quantitative PCR, denaturing gradient gel electrophoresis, high-throughput sequencing). Then, the interaction and relationship among in N2O fluxes and pathways, abundance and diversity of microbes as well as soil environment are discussed. The aim of the project is to reveal the mechanism of N2O emission from subtropical forest soils under different altitudes and to provide a scientific basis for mitigating global climate change process in subtropical forest ecosystems.