内蒙古典型草原表层土壤有机碳储量差异及影响因素

The Differences and Influencing Factors of Topsoil Organic Carbon Storage in Typical Steppe of Inner Mongolia

在内蒙古锡林河流域典型草原设置119个样地,确定群系序列,应用单因素方差分析法和最小差异法来对比分析不同群系0～30cm土壤有机碳储量的差异,并分析了表层土壤有机碳储量和植被群系类型、物种多样性、功能多样性、群落权重均值、地上生物量的关系。结果显示:(1)通过Canoco 5.0软件对119个样方进行PCA排序,结果确定出5个群系:羊草、大针茅、克氏针茅、苔草+委陵菜、冷蒿+冰草群系;(2)5个群系表层土壤有机碳密度变化范围为1.84～2.74 kg/m^2,平均值为2.41±0.84 kg/m^2,其大小关系为:羊草群系>大针茅群系>克氏针茅群系>苔草+委陵菜群系>冷蒿+冰草群系,其中冷蒿+冰草群系显著低于其他群系;(3)典型草原表层土壤有机碳储量与植被群系类型、地上生物量及叶面积呈显著正相关,其中植被群系类型是最主要的影响因素。

In this study, 119 sample plots were set up in the typical steppe of Xilin River Basin, Inner Mongolia.On the basis of determining the sequences of formations, one-way analysis of variance and least significant difference were used to compare the significant difference of 0~30cm soil organic carbon storage between different sequences.The relationship between surface soil organic carbon storage and vegetation formation types, species diversity, functional diversity, community weighted mean and aboveground biomass were analyzed by using correlation analysis.The results showed that:(1) PCA sequencing was performed on 119 sample plots using Canoco 5.0 software.Based on the sequencing results, five sequences of formation were identified: Leymus chinensis, Stipa grandis, Stipa krylovii, Carex duriuscula + Potentilla chinensis, Artemisia frigida + Agropyron cristatum formation.(2) The range of soil organic carbon density in the five formations was 1.84~2.74kg/m^2, with an average of 2.41± 0.84 kg/m^2.The relationship of size is: Leymus chinensis>Stipa grandis>Stipa krylovii>Carex duriuscula +Potentilla chinensis>Artemisia frigida+Agropyron cristatum formation.Among them, Artemisia frigida + Agropyron cristatum was significantly lower than the other four vegetation types.(3) There was a significant positive correlation between surface soil organic carbon storage and vegetation formation types, aboveground biomass and leaf area in typical steppe.The formation type of vegetation is the most important factor.