中文摘要：

以黑河中游湿地为研究对象,分析木本、高草、低草3种湿地植被类型土壤有机碳的分布特征及影响因素,结果表明,土壤有机碳含量的大小依次为高草〉低草〉木本植被类型,0-20 cm的差异均达到显著水平（p〈0.05）。低草植被类型有机碳的空间变异最大,木本植被居中,高草植被最小。高草、低草和木本植被0-40 cm土壤有机碳密度分别为7.33、5.44和4.25 kg/m^2。高草、低草植被以表层土壤（0-10 cm）有机碳含量更高,分别占0-40 cm的32%,31%,木本植被以亚表层（10-20 cm）最高,占33%。土壤有机碳含量与土壤含水量、磷素呈显著正相关（p〈0.05）,与土壤质量、pH值呈显著负相关（p〈0.05）。

英文摘要：

Wetland ecosystem plays an important role in global carbon budget. However, the soil organic car-bon （SOC） storage of wetland has been studied poorly in arid region. The distribution of SOC and its influence factors at three types of wetland vegetation （high herb vegetation, lower herb vegetation and woody vegeta-tion） were analyzed in the middle reaches of the Heihe River. The results showed that the SOC contents at 0-10 cm, 10-20 cm and 20-40 cm depths were in the order of high herb wetland vegetation 〉 lower herb wetland vegetation 〉 woody wetland vegetation. The differences in organic carbon content among the three types of wetland vegetation were significant at 0-10 cm and 10-20 cm depths of soil. The coefficient of variation of SOC was greatest in the lower herb wetland vegetation, and was least in the high herb wetland vegetation and secondary in the woody wetland vegetation. There was significant difference in SOC content between 0-10 cm and 20-40 cm depths of soil in the high herb wetland vegetation, difference was not significant in other two vegetation types. In accord with the distribution of SOC content, the soil carbon density in 0-40 cm depth was 7.33 kg/m^2, 5.44 kg/m^2 and 4.25 kg/m^2 at high herb wetland vegetation, lower herb wetland vegetation and woody wetland vegetation, respectively. At high herb wetland vegetation and lower herb wetland vegetation, the SOC content decreased with soil depth and was more concentrated in the surface layer （0-10 cm） account-ing for 32% and 31% of the total in 0-40 cm depth. While organic carbon content at the woody wetland vegeta-tion was larger at the soil depth of 10-20 cm （accounting for 33% of the total in 0-40 cm depth）. The SOC con-tent was positively correlated with soil water content （/9〈0.01） and phosphorus （p〈0.05）, and negatively corre-lated with soil bulk density （p 〈 0.01） and pH （p〈0.05）. Moreover, SOC content in wetland vegetation had no obvious relationships with soil salinity and altitude. The differ