【摘要】 额尔齐斯河河源区土壤碳、氮含量的空间分异对水源涵养区的水土保持和生态系统稳定性具有重要意义。以额尔齐斯河河源区生态系中3种典型植被类型(山地针叶林、温带草原和温带荒漠)下的土壤为研究对象，采用单因素方差分析比较不同植被类型下土壤碳、氮组分含量的差异，并通过冗余分析方法探讨土壤碳、氮元素的主要环境影响因素。结果表明:1)山地针叶林下土壤稳定性碳、氮含量最高，显著高于温带草原与温带荒漠土壤(P<0.05)。2)随海拔升高不稳定碳、氮含量由小到大依次为呈温带荒漠、温带草原、山地针叶林。3)不同植被类型下，土壤碳、氮的分布受环境因子影响存在差异，土壤含水率(SMC)、土壤盐分(SS)、植被覆盖率(FVC)和叶面积指数(LAI)为主要影响因子;其中SMC对温带草原的影响最大; SS对山地针叶林的影响最大。4)相同植被类型下，中纬度河源区的土壤碳、氮含量高于非河源区;低纬度河源区的土壤碳、氮含量高于中纬度地区。额尔齐斯河河源区土壤碳、氮含量受不同植被类型的显著影响，p H、SMC和SS为影响不同植被群落土壤碳、氮含量的主要环境因子。更多还原

【Abstract】 The spatial differences in soil carbon and nitrogen content in the source area are key to the water and soil conservation and ecosystem stability of the water source conservation area. Focusing on the source area of the Irtysh River ecosystem,we studied the carbon and nitrogen components of soils under three different vegetation types: Temperate desert,temperate meadows,as well as Mountain coniferous forests. Using redundancy analysis,we revealed the main environmental factors influencing soil carbon and nitrogen. The findings are as follows: 1) Mountain coniferous forests have the highest stable soil carbon and nitrogen content,which is significantly higher than that of temperate meadows and temperate deserts( P < 0. 05). 2) With increasing altitude,the unstable carbon and nitrogen content shows a descending gradient of temperate desert,temperate meadows and mountain coniferous forest. 3) Vegetation type is the main driver of soil carbon and nitrogen distribution,with soil moisture content( SMC),soil temperature( ST),fractional vegetation cover( FVC),and leaf area index( LAI) being the primary influencing factors. Among these,pH has the highest impact on soil carbon and nitrogen in temperate deserts,SMC is the highest impact factor for temperate meadows,and soil salinity( SS) is the highest impact factor for Mountain coniferous forests. 4) In the mid-latitude source area,soil carbon and nitrogen content under the same vegetation type is higher than in non-source areas,and in low-latitude source areas,it is higher than in mid-latitude regions. Overall,these results indicate that soil carbon and nitrogen content in the Irtysh River source area are influenced by different vegetation types,with pH,SMC,and SS being the main factors affecting soil carbon and nitrogen content across different vegetation communities.更多还原