中文摘要：

通过对喀斯特地区乔木林、灌木林和草丛不同植被类型覆盖下的土面、石面、石缝、石沟、石洞、石槽和石坑7类小生境土壤样品分析测定,探讨了小生境土壤矿物组成及有机碳的空间异质性特征。结果表明：（1）不同植被类型下土壤矿物组成存在明显差异,即从草丛→灌木林→乔木林,小生境土壤中的石英、高岭石基本保持不变,但草丛土壤中的白云石矿物全部消失,灌木林、乔木林土壤中逐渐出现绿泥石;（2）随着植被正向演替,土壤有机碳含量显著增加,小生境土壤有机碳含量在不同植被类型条件下存在明显的异质性,表现为草丛〉乔木林〉灌木林。与此同时,以小生境土壤有机碳含量及变异系数为评价因子,分别对乔木林、灌木林及草丛中小生境有机碳进行聚类分析,结果显示,小生境微地貌特征是土壤有机碳含量及空间变异性的重要影响因子。对于土壤有机碳保护,草丛及灌木林区应以提高植被覆盖率为主;乔木林区则主要是保持现有良好的植被状况,减少人为干扰。

英文摘要：

The spatial heterogeneity of soil mineral composition and soil organic carbon（SOC）are determined through sampling at 7 kinds of micro-habitats,including soil surface,rocky surface,stone crevice,stone gully,stone cavern and stone groove as well as stone pit,under different vegetation cover,arbor and shrub and grass as well,in karst region.The results prove that,（1） The composition of soil mineral is diversity under different vegetation types.Quartz and kaolinite in the soil do not change under grass and shrub as well as arbor vegetation cover,dolomite in the soil in grassland disappears,and chlorite gradually appears in the shrub and arbor forest.（2）With the vegetation succession,the content of SOC significantly increases,and the content of micro-habitats SOC shows evident heterogeneity as follows： grassland arbor forest shrub land.Moreover,taking the content of SOC and the coefficient of variation at micro-habitats as evaluation factors,cluster analysis to the SOC under arbor forest and shrub as well as glass covers is done.The results show that the micro-topography is very important factor affecting the content of SOC and its spatial heterogeneity.To protect the SOC,the major work is improving vegetation covered ratio in grass and shrub vegetation cover areas,and keeping the good conditions of vegetation and decreasing human interference in the arbor vegetation cover areas.