植物排放N2O和CH4的研究

N2O和CH4是2种重要的温室气体,但其排放源尚未得到充分鉴别.1990年和2006年先后报道植物能排放N2O和CH4,并日益受到广泛的关注.然而,迄今为止对植物排放这2种气体的研究均是分开单独进行的.该文以8种陆生草本植物为研究对象,首次同步考察了新鲜离体植物地上部排放N2O和CH4的通量.研究结果表明:8种植物均能排放这2种气体.其中,黑麦草(Lolium perenne)、抱茎苦荬菜(Ixendium sonchifolium)和菠菜(Spinacia oleracea)的CH4通量较高,分别为165.38、52.28和21.64 ngCH4.g-1dw·h-1;抱茎苦荬菜、蒙古蒿(Artemisia mongolica)、大豆(Glycine max)和菠菜的N2O通量较高,分别为7.19、6.92、5.44和4.05 ngN2O·g-1dw.h-1.研究结果不仅为植物本身既能排放N2O又能排放CH4在植物中可能具有普遍性提供了进一步的实验依据,而且为深入研究其机理找到了几种适宜的植物种(如抱茎苦荬菜、菠菜).

Investigation of N_2O and CH_4 Emissions from Plants

N2O and CH4 are two important greenhouse gases.However,their sources have not been well characterized.Plants are known to emit N2O and CH4,which has received widespread attention.We investigated N2O and CH4 emissions from fresh aboveground parts（branches and leaves） of 8 xerophytic herbaceous plants.All species could emit both N2O and CH4.Lolium perenne,Ixeridium sonchifolium and Spinacia oleracea showed high CH4 emission,with fluxes of 165.38,52.28 and 21.64 ngCH4？g–1dw？h–1,respectively.I.sonchifolium,Artemisia mongolica,Glycine max and S.ol-eracea emitted more N2O,with fluxes of 7.19,6.92,5.44 and 4.05 ngN2O？g–1dw？h–1,respectively.These results provide further evidence of the universality of plants emitting N2O and CH4 but also reveal suitable plant species（I.sonchifolium and S.oleracea） for further mechanistic studies.