【作者】 朝鲁蒙；

【导师】 王进鑫；

【作者基本信息】 西北农林科技大学 ， 水土保持与荒漠化防治， 2007， 硕士

【摘要】 黄土高原植被稀少,各种自然灾害频繁,水土流失严重,生态环境脆弱。为了改善日益脆弱的生态环境,保护农业生产,进行了60多年的研究与综合治理工作,取得了巨大的成就。目前农林复合系统研究主要集中在单一的生态系统内部,即同一类型的土地利用方式下的水文生态参数变化规律。国内外的生态学者对森林、草原和农田等不同生态系统内的土壤水文生态效应进行了大量的研究,然而对于不同生态系统边界上的研究却很少。研究不同农林复合结构条件下,系统水文生态参数的变化规律,必将对该区人工植被恢复与建设起到极大的促进作用。本文以陕西省淳化县泥河沟流域为研究区,以几种典型的农林复合模式为研究对象,通过野外调查、实验观测与测定分析,对几种典型农林复合模式的土壤水分分布规律、土壤水分入渗规律及其边界影响域等进行了初步研究,以期为黄土高原复合农林业建设与相关研究提供理论依据。主要研究结论如下:(1)在撂荒地、乔木、灌木、果树、小麦等植被覆盖类型中,撂荒地的0-200cm平均土壤含水率最高,为17.56%,其次为刺槐、油松、苹果园等根系较深的植被覆盖类型,在15.22%—16.59%之间,冬小麦、灌木林等植被的平均土壤含水率为较低,分别为14.33%和12.99%。乔木林和苹果园由于植株根系较深,主要利用深层土壤水,因此深层土壤含水率较低;小麦地与之相反,主要利用浅层土壤水。农林复合可以提高地表覆盖度,形成适宜的根系分布结构,从而有助于减少土壤水分蒸发损失,提高土壤水分利用率。(2)浑水入渗明显降低土壤入渗速率,降低的幅度林地要大于果园、农田和荒草地。土壤水分入渗采用Kostiakov的幂函数型式来进行描述,可较好的表明不同植被覆盖方式下的土壤水分入渗曲线的变化程度。Kostiakov公式中的a值表示初始入渗速率,a值与地表枯枝落叶层厚度等因素有关,变化顺序是林地>农地>荒草地>果园,b值反映土壤入渗强度,由稳定入渗率跟初始入渗速率决定,变化顺序是林地>荒草地>农地>果园。(3)采用移动窗口法得出的几种农林复合模式的土壤水分影响域为:农—果复合界面土壤水分影响域最大值为农地8m,果园6m;刺槐—油松复合界面土壤水分影响域最大值油松林为6m,刺槐林为8m;苹果—荒草地复合界面土壤水分影响域最大值为果园6m,荒草地10m;荒草地—灌木复合边界土壤水分最大值为荒草地8m,灌木10m。农—果复合界面上浑水入渗影响域为农地6m,果园4m。刺槐—油松复合界面上浑水入渗的影响域为刺槐6m,油松4m。苹果—荒草地复合边界上浑水入渗的影响域为荒草地8m,果园6m。(4)通过对复合界面上的土壤水分与浑水入渗的影响域的分析,从土壤水分充分利用这一角度出发,可以确定复合界面上植被带的宽度:农—果复合界面上冬小麦田的宽度建议选择16m,苹果园的宽度建议选择12m;刺槐—油松复合界面上油松林宽度建议为12m,刺槐林宽度建议为16m。更多还原

【Abstract】 Rare plant makes frequent natural disasters, serious soil erosion and fragile ecological environment in the Loess Plateau. In order to improve ecological environment and agricultural production, our country scholars worded on this job for 60 years, and made great achievement. Currently, agroforestry system mainly concentrated in a single ecosystem, that is, the parameters of the hydro-ecological changes under the same types of land uses. There are many researches on hydro-ecological effect in different ecosystem, however, the research on boundary of different ecosystem is less. Studies on the law of hydro-ecological parameters under different agroforestry structure, which take a positive effect on artificial vegetation restoration and construction.The research conclusions are shown as follows:(1) In different vegetation cover, the average of soil moisture at depth of 0-200cm for fallow is 17.56%, which is the highest. And the arbor and apple orchard’s soil moisture is between 15.22%-16.59%. The soil moisture of winter wheat and shrub is the lowest; it is 14.33% and 12.99%. Because of the root of arbor and apple orchard go deep and mainly use the soil moisture in great depth, the soil moisture in great depth is lower; By the contrary, the winter white use shallow layer soil moisture.Agroforestry can improve the surface coverage, develop a reasonable Root distribution structure, reduce soil water evaporization, and increase using of soil water.(2) Muddy infiltration can reduce soil water infiltration rate, and reduce range of forest land is more than that of apple orchard, agricultural land and fallow land. The Kostiakov exponential functions descript clearly soil water infiltration. Value a represent initial infiltration rate, and it is related with the thicker of forest floor, Soil density、soil moisture. value a is most in forest, the second in agriculture land, the third in fallow and the least in apple orchard, respectively. Value b represent soil water infiltration intensity, and it is significantly related with stable infiltration rate and initial infiltration rate, size order of b in different land using is forest, fallow, agricultural land and apple orchard(3) Based on split-window techniques to analyze soil water distance of edge influence for different agroforestry pattern. The result is: The distance of edge influence to soil water content were 8m & 6m for winter wheat– apple tree compound boundary respectively, 6m & 8m for Chinese pine - Black locust compound boundary, 6m & 10m apple tree– grassland compound boundary,8m & 10 m grassland–shrubbery compound boundary. The distance of edge influence to muddy infiltration were 6m & 4m for winter wheat– apple tree compound boundary respectively, 4m & 6m for Chinese pine - Black locust compound boundary, 6m & 8m apple tree– grassland compound boundary.(4) We analyzed the distance of edge influence to soil water and muddy infiltration for different compound boundary, based on efficient use of soil water, can decide width of plants at compound boundary: we can decide 16m & 12m for winter wheat– apple tree compound boundary, 12m & 16m for Chinese pine - Black locust compound boundary.更多还原