桂西北喀斯特峰丛洼地坡面土地利用对土壤水分的影响

Effect of Land Use on Soil Moisture on hillslope in Karst Peak-Cluster Depression Areas of Northwest Guangxi

通过对桂西北喀斯特峰从洼地坡面不同立地类型和土地利用构型的土壤水分特征进行定位观测研究,分析了土壤水分的空间异质性及其与土地利用方式及结构之间的关系。结果表明,喀斯特峰从洼地坡面土壤水分随土层加深,均值升高,空间异质性(变异系数)却有所减小,土壤水分的均值和空间异质性随着时间(降雨)也表现出一定的变化规律;方差分析和多重比较表明,土地利用方式对土壤水分的空间异质性具有显著的影响,次生林和灌丛地土壤水分含量较高,经济林地各土层和观测时段土壤含水量都显著低于其他土地利用方式;通过分析研究区3种主要的土地利用结构对坡面土壤水分的影响,提出调整土地利用结构和布局能有效提高土壤含水量。

Based on fixed and consecutive measurements of soil moisture characteristics in peak-cluster depression areas of Karst mountainous region, the degree of spatial heterogeneity of soil moisture content and the spatio-temporal relationships between soil moisture and land use were analyzed. The results are as follows： With the increase of soil depth, the mean soil moisture content increased whilst the spatial heterogeneity exhibited an opposite pattern, and the temporal changes in the mean and the heterogeneity of soil moisture content were also obvious. The results of analysis of variance and multiple comparison showed that the effects of land use on soil moisture were statistically different, and secondary forest and natural shrub had higher water contents than economic forest lands. After the effect of three land use structures on soil moisture along hillslope were analyzed, activities accorded with ecological principal such as readjustment of land use structure were proved to be effective approaches in water conservation in the Karst region.