喀斯特峰丛洼地次生林主要土壤矿质成分空间异质性研究

摘要

This study was carried out to examine the spatial heterogeneity of soil minerals (SiO2、Fe2O3、CaO、MgO、 Al2O3、MnO) in secondary forest in karst cluster-peak-depression region using methods of classical statistics and geostatistics. Eighty soil samples of 0cm-20 cm layer were taken on the 200 m ×40 m scale. The results showed that the differences of the six mineral compositions were large, and the contents of soil mineral compositions were in the order of SiO2> CaO> Al2O3> MgO> Fe2C>3>MnO, and the variance coefficients ranged from 37.8% to 54.6%. Gaussian model fitted best for MnO, and Spherical model fitted best for other mineral compositions. MgO had medium spatial autocorrelation, while the others were characterized by strong spatial autocorrelation. The Kriging contour map of CaO was similar with that of MgO. The Kriging contour maps of Fe2O3, Al2O3, and MnO were similar. Most of the high-value area of SiO2 appeared on upper slope and a small on the mid-low slope. The results indicated that topography, micro-physiognomy, precipitation, human disturbance, and especially vegetation were the most important factors affecting the spatial pattern of soil mineral composition. Increasing plant diversity and coverage would be of great importance for improvement of soil mineral composition, rational utilization, and ecological restoration and reconstruction.%应用经典统计学和地统计学方法研究了喀斯特峰丛洼地次生林地200 m×40m尺度下表层(0 cm -20 cm)土壤矿质成分(SiO2、Fe2O3 、CaO、MgO、Al2O3、MnO)的空间异质性.结果表明:研究区6种矿质成分含量的差异较大,SiO2＞CaO＞Al2O3＞MgO＞Fe2O3＞MnO,变异系数为37.8％-54.6％.SiO2、Fe2O3、CaO、Al2O3、MnO的半方差函数最佳拟合模型为球状模型,MsO的最佳拟合模型为高斯模型,除MgO呈中等空间自相关外,其他矿质成分空间自相关强烈.CaO和MgO及Fe2O3、Al2O3和MnO的Kriging等值线图相似,SiO2的高值区出现在坡顶和坡中下部.地形、微地貌、降雨、人为干扰特别是植被是土壤矿质成分空间异质性的主要影响因素,增加植物多样性和覆盖度对喀斯特土壤矿质成分的改善、合理利用和生态恢复重建具有重要的指导意义.