中文摘要：

2013-07-09在申扎高寒草原与湿地生态系统观测试验站的半干旱高寒草原试验地,采用静态箱-气相色谱法对施加牦牛粪便、藏绵羊粪便和不施加粪便处理土壤的CH4排放特征进行了观测研究.结果表明,牦牛粪便斑块的CH4累积排放量为70.2 mg C/m2,显著高于藏绵羊粪便处理的-34.0 mg C/m2和对照处理的-69.0 mg C/m2,两者之间也有显著差异.牦牛粪便处理CH4的净排放主要是由于粪便施加后前期CH4的大量排放所致,藏绵羊粪便与对照处理之间的差异则主要归因于观测后期前者的CH4吸收量显著低于后者.牦牛粪便处理的CH4排放系数和干重排放指数分别是藏绵羊粪便处理的2.1倍和2.4倍.牦牛粪便斑块释放的绝大部分CH4主要来自于粪便本身,藏绵羊粪便斑块的较低含水量和较少有机碳施加量是致使其产甲烷潜力小于牦牛粪便斑块的主要原因.

英文摘要：

To investigate the effects of yak and Tibetan sheep dung on CH4 emissions from an alpine steppe soil in Northern Tibet, China, a field experiment was conducted, to measure CH4 fluxes from simulated yak and Tibetan sheep dung patches and the Control plot using closed chamber technique and gas chromatography during an observa- tion period from July to September in 2013, at Xainza Alpine Steppe and Wetland Ecosystem Observation Station. Cumulative CH4 emission from the yak dung treatment was 70.2 mg C/m2 , significantly higher than those from the treatments of Tibetan sheep dung （ -34.0 mg C/m2） and Control （ -69.0 mg C/m2）, and the values were also significantly different between the latter two treatments. The net release of CH, from yak dung patch was mainly caused by the massive methane emissions from earlier stage during the observation period, and the difference in CH, fluxes between the Control and Tibetan sheep dung treatments was probably due to the lower methane absorption by soil in the Tibetan sheep dung treatment from latter stage. CH4 emission factors and dry weight-release index for yak dung treatment were 2.1 and 2.4 times of those for Tibetan sheep dung treatment. It is likely that most of the CH4 from yak dung patch was derived from the CH4 released from the yak dung itself, and the lower water con- tent for Tibetan sheep dung and less organic carbon addition to the alpine steppe soil probably resulted in lower po- tential for CH4 production in Tibetan sheep dung treatment in comparison to yak dung treatment.