土壤温室气体产生与排放影响因素研究进展

土壤是温室气体(如CO2、CH4和N2O)产生的重要源,土壤温室气体主要来自于微生物呼吸,植物根呼吸和土壤动物呼吸。土壤温室气体排放机制及其影响因素是研究全球碳氮循环的重要组成部分。研究表明,影响土壤呼吸的因素很多,土壤理化性质如温度、含水量、有机质含量、pH值、氧化还原电位(Eh)、土壤质地等因素都可以直接影响土壤微生物量及其生理生化过程,从而影响温室气体排放。其中,土壤温度,湿度、有机质含量是关键性因素。此外,地域气候、土地利用以及土地覆盖变化也可以通过改变土壤理化性质及呼吸底物来影响温室气体排放。文章重点论述了土壤温室气体排放机制,排放影响因素以及排放的日变化和季节变化规律。认为今后的研究方向应该是土壤微环境碳氮循环机制,土壤呼吸模型在尺度上的推延,以及注重中国陆地与近海生态系统碳固定及减少碳排放的对策和应用技术研究,特别在人工林碳固定及农业固碳减排方面加大研究力度等。

Mechanism of greenhouse gases fluxes from soil and its controlling factors: A review

Soil is a major source of greenhouse gases (GHG), such as carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), which are mainly resulted from root respiration, microbial respiration and soil fauna respiration. Study on the mechanism of GHG generation and influencing factors is one of the major concerns on global carbon and nitrogen cycle. A number of factors, including soil temperature, soil water content (SWC), soil organic matter (SOM), pH, Soil redox potential (Eh), soil texture, etc. contribute a lot to GHG fluxes by influencing soil microbial biomass, physiological and biochemical processes. Among these, soil temperature, SWC and SOM are identified as the main parameters in relation to soil GHG emission. Furthermore, local climate situation, soil management, land-use changes and vegetation cover also play a role in GHG emission by affecting microbial activity and substrate quality. The review highlights recent work on the mechanism of GHG fluxes, key factors, diurnal and seasonal variation. We suggest that future research should focus on dynamics of GHG fluxes within micro-environment, efflux modeling and its scaling-up, carbon sequestration and carbon mitigation in terrestrial ecosystem and coastal ecosystem, especially for plantation and farmland in China.