机构地区: 华南农业大学林学院
出 处: 《华南农业大学学报》 2006年第3期21-25,共5页
摘 要: 基于20个150m×150m的网格对东莞林科园进行土壤剖面取样,探讨其土壤水分的水平与垂直空间分布规律.研究结果表明:土壤水分的水平分布规律是除自然含水量为显著差异(P=0.0268)外,土壤容重(P=0.0003×10^-4)、最大持水量(P=0.0030)、田间持水量(P=0.0014)、毛管持水量(P=0.0019)和总孔隙度(P=0.0002×10^-4)均为极显著差异;垂直分布规律是土壤容重随土层深度的增加而增加,但异质性不显著(P=0.3812),最大持水量(P=0.0102)、田间持水量(P=0.0182)、毛管持水量(P=0.0822)和土壤总孔隙度(P=0.4136)随土层深度的增加而减少,但其中毛管持水量和土壤总孔隙度的差异不显著,土壤自然含水量表层0~20cm的较小,土层20-40cm的最小,土层40~60cm的最大,且各层次之间的自然含水量的异质性不显著(P=0.7558).对5个土壤水分指标进行主成分分析(PCA)表明,第一和第二主成分分别解释了68.56%、18.71%的变异,即土壤水分特征主要由最大持水量、田间持水量,毛管持水量和总孔隙度决定的. Soil moisture characteristics and horizontal and vertical distribution of them were explored based on samples collected from 20 profiles, using a grid system of 150 m × 150 m superimposed on the study area of Dongguan Forest Experimental park. The results of this study showed that horizontal gradient in moisture content was significant (P =0. 026 8) ,and in bulk density(P =0. 000 3 × 10 ^-4), maximum moisture capacity ( P = 0. 003 0 ), field capacity ( P = 0. 001 4 ), capillary moisture capacity ( P = 0. 001 9) and total porosity (P =0. 000 2 × 10^ -4) was highly significant between the 20 soil profiles. As for vertical distribution, maximum moisture capacity (P =0. 010 2), field capacity (P =0. 018 2), capillary moisture capacity (P =0. 082 2) and total soil porosity (P =0. 413 6) decreased with soil depth except the water content (P = 0. 755 8 ), but the bulk density ( P = 0. 381 2) increased with soil depth. The principal component analysis (PCA) was employed to characterize five soil moisture indexes. The results demonstrated that, the soil moisture was determined by the maximum moisture capacity, field capacity, capillary moisture capacity, and total soil porosity.
领 域: [农业科学]