农田土壤主要温室气体(CO_2、CH_4、N_2O)的源/汇强度及其温室效应研究进展

Research advances on source/sink intensities and greenhouse effects of CO_2,CH_4 and N_2O in agricultural soils

气候变化是当今全球面临的重大挑战,人类社会生产生活引起的温室气体排放是全球气候变暖的主要原因。大气中CO2、CH4和N2O是最重要的温室气体,对温室效应的贡献率占了近80%。据估计,大气中每年有5%～20%的CO2、15%～30%的CH4、80%～90%的N2O来源于土壤,而农田土壤是温室气体的重要排放源。本文重点阐述了农田土壤温室气体产生、排放或吸收机理及其影响因素,指出土地利用方式和农业生产力水平等人为控制因素通过影响土壤和作物生长条件来影响农田土壤温室气体产生与排放或吸收。所以,我们可以从人类活动对农田生态系统的影响着手,通过改善农业生产方式和作物生长条件来探索温室气体减排措施,达到固碳/氮增汇的目的。对国内外关于农田温室气体排放的源/汇强度及其综合温室效应评估的最新研究进展进行了综述,指出正确估算与评价农田土壤温室气体的源/汇强度及其对大气中主要温室气体浓度变化的贡献,有助于为温室气体减排以及减少气候变化预测的不确定性提供理论依据。

Climate change is an increasing global challenge.Greenhouse gas emission via anthropogenic processes is the main cause of global warming.CO2,CH4 and N2O are the main greenhouse gases,accounting for ≈80% of greenhouse effect.It is esti-mated that each year,5%～20% of CO2,15%～30% of CH4 and 80%～90% of N2O in air are emitted from soils.Agricultural soils are the main sources of greenhouse gas emission.This work expatiated the mechanisms and affecting factors of greenhouse gas forma-tion,emission and absorption in agricultural soils.And the contribution of farmland ecosystem to greenhouse effects was discussed.It was indicated that anthropogenic factors such as land use and agricultural activity influenced greenhouse gas formation,emission and absorption in agricultural soils.Because anthropogenic processes affected agricultural ecosystems,greenhouse gas emission re-ductions for stabilized carbon and nitrogen were possible through improved agricultural cultivation and production systems.This study summarized the latest research advances in source/sink intensities of greenhouse gas emissions from farmlands and how that contributes to greenhouse effect.The study suggested that accurate estimation of source/sink intensities of greenhouse gases and ap-propriate assessments of greenhouse gas effects were the theoretical basis for reducing greenhouse gas emissions and uncertainties in predicting climate change.