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以空间代替时间的方法,在同一小流域选择华北落叶松+灌木复层林和稀植乔木天然灌丛作为调整后的目标林分,并以与此相邻的华北落叶松单层人工纯林和天然灌丛作对照,分析两种现有林分经过调整后对其土壤水分物理性质及水文功能的影响。结果表明:(1)与对照样地相比,华北落叶松+灌木复层林0-100cm土壤各层次的土壤容重降低5.52%~12.07%,土壤孔隙度提高4.82%~38.45%;而稀植乔木天然灌丛0-60cm剖面的容重降低10.09%~18.10%,土壤孔隙度提高5.02%~74.33%。(2)稀植乔木天然灌丛的土壤最大持水量、田间持水量和毛管持水量在0-60cm土层上分别比对照样地提高32.00%,26.31%,23.49%;而华北落叶松+灌木复层林与单层纯林相比,各指标分别提高38.45%,1.22%,0.17%;土壤蓄水性能表现为华北落叶松+灌木复层林(3 063t/hm2)>华北落叶松人工单层纯林(2 590t/hm2),稀植乔木天然灌丛(3 287t/hm2)>天然灌丛(2 937t/hm2)。(3)除10-20cm土层外,稀植乔木天然灌丛各层的土壤稳渗速率均与对照样地呈显著性差异(P<0.05);华北落叶松人工纯林经过改造后,不同土层的稳渗速率分别提高50.86%,14.90%,6.25%和34%。(4)各种林分类型的土壤稳渗速率与其孔隙度呈极显著地正线性关系(P<0.01)。以上结果说明,通过采取稀植乔木和单层纯林复层改造等措施可以明显地改善天然灌丛和华北落叶松人工单层纯林的土壤生态水文功能。
Taking space instead of time as the target, the Larix principis-rupprechtii single-layer artificial pure forests and Larix principis-rupprechtii canopy can be selected as the target forest in the same small watershed. Natural shrubs as a control, analysis of two existing stand after adjustment of its physical properties of soil moisture and hydrological functions. The results showed that: (1) Compared with the control plots, the bulk density of soil layers at 0-100 cm layer in Larix principis-rupprechtii + shrub-clad forest decreased 5.52% ~ 12.07% and the soil porosity increased by 4.82% ~ 38.45% The bulk density of 0-60cm section in natural shrubs decreased by 10.09% ~ 18.10% and the soil porosity increased by 5.02% ~ 74.33%. (2) The maximum soil water holding capacity, field water holding capacity and capillary holding capacity of natural shrubs with sparsely planted trees increased by 32.00%, 26.31% and 23.49% respectively over the 0-60cm soil layer, while those of Larix principis-rupprechtii Compared with the single-layer pure forest, the index of the single-layer pure forest increased by 38.45%, 1.22% and 0.17% respectively. The soil water storage performance was Larix principis-rupprechtii + shrubbery (3 063t / hm2)> Larix principis- (2 590 t / hm2), thinning of natural shrubs (3 287 t / hm2)> natural shrubs (2 937 t / hm2). (3) The soil infiltration rates of all layers except the 10-20cm soil layer were significantly different from those of the control plots (P <0.05). After transformation, the artificial pure forest of Larix principis-rupprechtii The soil infiltration rate increased by 50.86%, 14.90%, 6.25% and 34% respectively. (4) There was a significant positive linear correlation between the soil infiltration rate and the porosity of various forest types (P <0.01). The above results show that soil ecological and hydrological functions of natural shrub and Larix principis-rupprechtii canopy can be significantly improved by adopting such measures as replanting of thinning-planting tree and single-layer pure forest.