中文摘要：

以牛羊为主的反刍动物养殖是我国甲烷的首要排放源,其中又以牛的排放占主导。我国的养殖牛中,黄牛的数量最为庞大,占总存栏牛的56%。在以往有关反刍动物甲烷排放的研究中,着重点多在于排放因子的测定及依据测定结果估算国家尺度的排放源清单。但是,对于反刍动物种群特征及环境因子变化造成的动物甲烷排放在空间和季节的差异却较少关注。本研究收集了我国不同地区46个亚科黄牛的个体特性数据及其生态因子,结合IPCC的反刍动物甲烷排放估算方法,分析了我国2005年黄牛甲烷排放因子的空间差异及其季节变化特征。结果表明,总体上农区肠道发酵排放因子,除4-6月因役用强度大的原因,而排放略高于牧区外,其他月份均小于牧区,而农区粪便管理排放因子全年高于牧区。肠道发酵排放因子在夏季小于其他季节,其月均排放因子为4.48 kg/head/m,粪便管理排放因子则表现出相反的季节格局,夏季粪便管理月均排放因子为0.44 kg/head/m。在7个大的分区中,肠道发酵年排放因子最大、最小区域分别为黄土高原区71.0 kg/head/a和西南区55.2 kg/head/a;粪便管理年排放因子最大、最小区域分别为东南区5.4 kg/head/a和青藏区0.1 kg/head/a。

英文摘要：

Ruminant livestock accounts for the major proportion of methane emissions within the agricultural sector. In China, cattle dominates the livestock due to its huge population and large size in comparison to sheep.The latest studies have paid little attention to the spatial variations and seasonal changes of the livestock methane emission factors, though a lot of direct measurements and modeling estiamtions have been made to improve the quality of the national inventories. In this study, we analyzed the spatial variarions and seasonal changes of the methane emission factors of cattle by studing the spatio-temporal differences in the body weight for 46 cattle species, the feeding and diet, and the draft and milk production in different places of China are also discussed.The Tier 2 equations of IPCC（2006） were used to calculate the methane emission factors from both the enteric and the manure management emissions. The calculation showed that the enteric emission factor was general low in summer（4.48 kg head-1 month-1） and high in other seasons, while the emission from manure management was high in summer（0.44 kg head-1 month-1） and low in other seasons. Spatially, northwestern China has a higher enteric methane emission factor（71.0 kg head-1 year-1） than southwestern China（55.2 kg head-1 year-1）. The methane emission factor from manure management was low（0.1 kg head-1 year-1） in Tibetan plateau and high（5.4 kg head–1year–1） in southeastern China.