木论喀斯特自然保护区表层土壤矿物质的空间异质性

摘要

为了探明喀斯特峰丛洼地土壤矿物质的分布规律,为喀斯特地区植被恢复和生态重建提供参考,该研究基于动态监测样地(200 m×100 m)的网格取样分析,采用经典统计学和地统计学方法研究了喀斯特木论自然保护区典型峰丛洼地表层(0～20 cm)土壤矿物质(SiO2、Fe2O3、CaO、MgO、Al2O3、MnO)的空间异质性.结果表明,研究区土壤6种矿物质含量的差异及变异系数均较大,SiO2和Al2O3占了土壤矿物质总量的89.53％.不同矿物质具有不同的空间结构和最佳拟合模型,SiO2和MnO呈中等空间自相关,变程长,空间连续性较好,Fe2O3、A12O3、CaO、MgO的空间自相关强烈,变程较短.CaO和MgO的Kriging等值线图相似,SiO2反之,Fe2O3和Al2O3呈相似分布,MnO的分布均匀.地形、微地貌、降雨、人为干扰特别是植被是土壤矿物质空间异质性的主要影响因素,增加植物多样性和覆盖度能有效改善和合理利用喀斯特土壤矿物质资源.%In order to explore the distribution pattern of the main soil mineral components in karst cluster-peak depression area and to guide vegetation restoration and ecological reconstruction in the area, the spatial heterogeneity of mineral components (SiO2, Fe2O3, CaO, MgO, A12O3, and MnO) in surface soil (0-20cm) in Mulun National Nature Reserve was studied by the methods of classical statistics and geostatistics. The soil samples were collected with grid method based on a dynamic monitoring plot (200 m × 100 m) in Mulun National Nature Reserve karst cluster-peak depression area. The results showed that the content differences of the six mineral components were large, and the sum of SiO2 and A12O3 accounted for 89.53% of the total six mineral components. The variance coefficients of all the six mineral compositions were large. The spatial patterns of the six mineral components were quite different from each other, and fit to different models of mineral components. Both SiO2 and MnO had medium spatial autocorrelation with long range and well spatial continuum. Fe2O3, A12O3, CaO, and MgO were characterized by strong spatial autocorrelation with short ranges. The Kriging contour maps indicated that the distribution pattern of CaO and MgO were similar, but opposite to that of SiO2. And the distribution pattern of Fe2O3 was similar with that of A12O3, while MnO was in a relative homogeneous distribution status. The results indicated that topography, micro-physiognomy, precipitation, the history of human disturbance, and especially vegetation were the most important factors that affecting the spatial patterns of soil mineral components in karst cluster-peak depression region. Therefore, increasing plant diversity and vegetation coverage would be of great importance for effective improvement and rational utilization of soil mineral resources.