荒漠土壤氧化亚氮排放及其驱动因素研究进展

A review of research progress on nitrous oxide emissions from desert soil and its driving factors

氧化亚氮(N_(2)O)具有寿命长、增温潜势高且对臭氧层破坏性大等特点,陆地生态系统是其产生的主要来源。温度升高、降水变化以及由此引起的土壤中多种生物过程的改变,会促进或抑制N_(2)O排放,进而对环境产生深远影响。基于此,本文回顾和总结了有关国内外荒漠区土壤N_(2)O排放的研究进展,分析了荒漠土壤N_(2)O的产生-排放过程及排放通量,并详细综述了环境因子、土壤生物和非生物因素对荒漠土壤N_(2)O排放的影响机制。结果表明:荒漠土壤N_(2)O排放由硝化作用和反硝化作用主导,且具有明显的季节特征,具体表现为生长季排放量高,非生长季排放量低甚至为负。在总结已有研究的基础上,展望了荒漠区土壤N_(2)O排放的研究方向及亟待解决的问题:(1)基于同位素示踪技术及分子生物学技术探究微生物及相关功能基因对荒漠土壤N_(2)O产生和消耗的影响;(2)探究不同时间尺度(日、月、季节以及年际)多因素交互作用下荒漠土壤N_(2)O排放规律;(3)完善荒漠生态系统N_(2)O排放模型,并评估其对环境变化的影响。

Nitrous oxide(N_(2)O)has the characteristics of long lifespan,high warming potential and great damage to the ozone layer.Terrestrial ecosystem is the main source of N_(2)O.Global climate change lead to the change of temperature,rainfall and biological process in desert ecosystem,which will promote or inhibit N_(2)O emissions and further influence of the environment.Therefore,this paper summarized the latest domestic and foreign researches on soil N_(2)O emission in desert regions.We analyzed the production process and emission flux of N_(2)O in desert soil,and further reviewed the effect of environmental factors and soil biological and abiotic factors on desert soil N_(2)O emission.The soil N_(2)O emission in desert ecosystems,dominated by nitrification and denitrification,has seasonal characteristics(high emissions in growing season and low emissions or absorb N_(2)O in nongrowing season).On the basis of the previous researches,some topics that need to be solved urgently in the research field about soil N_(2)O emission are prospected at the end of this paper.The ideas and pathways solve these problems as follows:firstly,isotope tracer method and molecular biological technique should be used to explore the effects of soil micro-organisms and its related functional genes on N_(2)O emissions and consumption in arid and semi-arid regions;secondly,investigate the patterns of N_(2)O emissions in desert soils under the interaction of multiple factors at different time scales(daily,monthly,seasonal and interannual);thirdly,refine the N_(2)O emission models in desert ecosystems and assess the impact of N_(2)O emission on environmental change.