采集青藏高原高寒草甸15种优势植物进行室内沙培实验,利用静态箱-气相色谱法测定其甲烷通量,以确定其对大气甲烷的源汇效应；对植物体实施横切、纵切处理,研究植物甲烷排放的机制.结果显示:8种植物为大气甲烷的源,多为草本植物,7种为大气甲烷的汇,多数灌木植物吸收甲烷；横切、纵切处理对于植物甲烷释放速率的影响显著(p＜0.05),释放甲烷的植物中5种植物纵切后甲烷释放速率增加,增幅10.9％～ 244.06％,6种植物横切后甲烷释放速率增加,增幅27.04％～37.44％,灌丛植物在横切、纵切处理后甲烷通量都呈降低的趋势；对植物纵切处理后甲烷释放速率显著高于未处理与横切处理后植物甲烷释放速率,推测是由于几种处理间对于植物维管束处的气腔破坏程度不同造成的；温度对于植物的甲烷行为影响显著(p＜0.05),随着温度的升高植物甲烷的源/汇效应均呈现增加趋势,甲烷源植物Q10=1.75,甲烷汇植物Q10 =1.44.%To determine the methane flux of dominant species of alpine meadow, we had done a indoor cultivation of 15 kinds of dominant species by using closed chamber - GC method from may to august in 2009, and did a comparative study on cross-section treatment and longitudinal treatment to find the effect factors of plants methane emission rate. The result shows that,8 species of them emitted methane ,the other 7 absorbed methane, 7 out of 11 herb species emitted methane and 3 out of 5 shrub species sborbed methane; Mehtane flux rate remarkably influenced by temperature (p < 0. 05 ) , Q10 of these methane emission plants was 1.75, then Q10 of the asorbtion plants was 1. 44; methane emission rate increased by 10. 9% -244. 06% after the cross-section treament, and plants methane emission rate increased by 27. 04% ～37. 44% to longitudinal treament,all the shrub species methane flux decline after cross-section and longitudinal treament. The methane emission rate to longitudinal treament was significantly higher than the other two treatments (p <0. 05).
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