【摘要】 [目的 ]研究喀斯特白云岩区典型植被类型土壤水分的空间变化及分布规律,为石漠化地区植被快速恢复和生态重建提供科学依据。[方法 ]以贵州省普定县喀斯特白云岩草地、灌丛、人工林和天然次生林4种不同植被类型土壤为研究对象,于2019年11月利用网格法分0～10 cm和10～20 cm土层进行土壤取样并分析,利用经典统计学和地统计学方法分析土壤水分含量及其空间变异特征。[结果 ](1)除草地和人工林之间差异不显著外,不同植被类型间土壤水分含量呈极显著差异(p <0.01),土壤水分含量从高到低依次为:天然次生林>草地>人工林>灌丛,最大值(40.22%)是最小值(18.59%)的2.16倍,变异系数为5.34%～29.42%。(2)草地和灌丛浅层土壤水分半变异函数的最优模型为高斯模型,深层土壤为指数模型,人工林和天然次生林均为指数模型,草地变程最小(4.24 m),而人工林变程最大(16.48 m),灌丛基台值最大(14.42),天然次生林块金值最大(1.27)。(3)土壤水分含量最高值均发生于样地内上半部,深层土壤水分含量高于浅层土壤,且同种植被类型在0～20 cm土层有相似的空间分布格局。(4)土壤水分含量与土壤总孔隙度成正相关,与土壤密度成负相关,植被类型也在一定程度上影响土壤水分含量,但并非随植被的正向演替而增加。[结论 ]不同植被类型土壤水分空间结构明显,有强烈的空间自相关性,4种植被类型中天然次生林土壤水分含量最高,草地土壤水分连续性最差,人工林土壤水分连续性最好,同种植被类型在0～20 cm土层水分分布相似。在相同气象条件下,植被类型、坡位、土壤密度和孔隙度可能是影响土壤水分含量分布的重要因子。更多还原

【Abstract】 [Objective] To investigate the spatial variation and distribution of soil moisture with typical vegetation types in Karst dolomite area in order to provide data for rapid vegetation restoration and ecological reconstruction.[Method] Considering soil of karst dolomitic grassland, shrub, plantation and natural secondary forest in Puding County of Guizhou Province as research object, soil samples were collected in two layers(0-10 cm and 10-20 cm) by using grid method in November 2019 to determine the soil bulk density, porosity and water content. The soil moisture content and spatial variation characteristics were analyzed by using classical statistics and geostatistics.[Result](1) Significant differences were found in soil moisture content among different vegetation types(p < 0.01),but there was no significant difference between grassland and plantation. The soil moisture content decreased in the order as followed: natural secondary forest > grassland > plantation > shrub. The maximum(40.22%) was 2.16 times of the minimum(18.59%) and the coefficient of variation ranged from 5.34% to 29.42%.(2) The optimal model of semi-variogram of soil moisture in shallow layer of grassland and shrub was Gaussian model, while the others were exponential models. The range of grassland was the smallest(4.24 m), while the range of plantation was the largest(16.48 m); the sill value of shrub was the largest(14.42), and the nugget value of natural secondary forest was the largest(1.27).(3) The highest soil moisture content occurred on the uphill slope in all plots, and the shallow soil moisture content was higher than the deep one. Furthermore, the same vegetation type had similar spatial distribution pattern in the vertical direction.(4) The soil moisture content was positively correlated with total soil porosity while negatively correlated with soil bulk density. Vegetation type also affected soil moisture content to a certain extent, but not with the positive succession of vegetation. [Conclusion] The spatial structure of soil moisture among different vegetation types is obvious, and there has a strong spatial autocorrelation. The soil moisture content of the natural secondary forest is the highest among the four types; the soil moisture continuity is the worst in grassland and the best in the plantation; the distribution of soil moisture in the same vegetation type is similar in the vertical direction. In the same weather conditions, the vegetation type, slope, soil bulk density and porosity might be the important factors affecting the distribution of soil moisture content.更多还原