| 摘要: |
| 【目的】探明西藏尼洋河流域下游不同土地利用方式对土壤物理性质的影响，为该地区水土流失治理提供理论依据。【方法】在尼洋河下游河谷地带，采集天然林地、人工林地、河滩林地、农耕地、草地5种典型土地利用方式，选取每个样点0～15，15～30 cm土层样品，测定土壤体积质量，孔隙度（总孔隙度、毛管孔隙度、非毛管孔隙度），含水率（饱和含水率、毛管含水率），田间持水率，渗透性（初始渗透速率、稳定渗透速率、平均渗透速率），并对各指标的相互关系进行了分析。【结果】不同土地利用方式土壤体积质量、孔隙度、持水性能有明显差异，土壤体积质量表现为0～15 cm土层<15～30 cm土层,人工林地（1.51 g/cm3）>农耕地（1.40 g/cm3）>草地（1.16 g/cm3）>河滩林地（1.12 g/cm3）>天然林地（0.92 g/cm3）。天然林地土壤总孔隙度、毛管孔隙度、非毛管孔隙度均明显大于其他土地利用方式，且土壤体积质量与土壤总孔隙度呈显著负相关关系。天然林地饱和含水率、毛管含水率均极显著大于其余土地利用方式。除河滩林地外，其余土地利用方式下土壤饱和含水率、毛管含水率随土层深度增加呈减小趋势。土壤饱和含水率、毛管含水率、田间持水率与土壤体积质量呈显著性负相关关系，与总孔隙度呈显著正相关关系。各土地利用方式下土壤渗透性存在一定差异，但大多差异未达显著水平，具体表现为:天然林地>河滩林地>农耕地>人工林地>草地。除草地外，其余4种土地利用方式下渗透性均随土层深度增加而增强。【结论】不同土地利用方式对土壤物理性质影响有差异，其中天然林地土壤物理性质最优，人工林地较差，在进行土地利用时应减少人为干扰强度，避免对自然植被产生破坏。 |
| 关键词: 土地利用方式 土壤体积质量 土壤孔隙度 土壤持水性 渗透性 |
| DOI： |
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| 基金项目:国家自然科学基金项目(41461063) |
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| Differences in soil physical properties of 5 typical land use types in downstream of the Niyang River in Tibet |
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LIANG Bo,NIE Xiaogang,YANG Dongsheng,et al
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| Abstract: |
| 【Objective】This study focused on ascertaining the influences of land uses on soil physical properties to provide theoretical foundation for conservation of water and soil in downstream of the Niyang River Valley.【Method】Properties such as soil bulk density,porosity,moisture content,field capacity,and permeability of soil samples collected at different depths of 0-15 cm and 15-30 cm in natural woodland,artificial forest,valley forest,farming land and grass land,in downstream of the Niyang River Valley were determined and the relationships between them were analyzed.【Result】Soil volume-weights,porosities and field capacities of water varied significantly for different land uses.Soil volume weights in 0-15 cm were larger than that in 15-30 cm.Soil volume-weights in artificial forest,farming land,grass land,and valley forest were 1.51,1.40,1.16,1.12,and 0.92 g/cm3,respectively.The total porosity,capillary porosity,and non-capillary porosity in natural forest were generally larger than those in other land uses.The soil volume weight had negative correlation with porosity.The field capacities of soil water,saturated water content,and capillary moisture content had negative correlation with soil volume-weight, and positive correlation with total porosity.Saturated water content and capillary moisture content in natural forest were significantly larger than those in other land uses.Except for valley forest,saturated water content and capillary moisture content showed decreasing trends as the increase of soil depth.The permeability in different land uses showed insignificant differences,and it had a decreasing order of natural forest > valley forest > farm land > artificial forest > grass land.Except for grass land,the permeability in other land uses had positive correlation with depth of soil layer.【Conclusion】Different land uses had significant influences on soil physical properties.The soil physical properties were best in natural forest and worst in artificial forest.Therefore,human disturbance should be limited and destructions on natural vegetation should be avoided when using land. |
| Key words: the pattern of land use soil volume-weigh soil porosity soil water holding capacity permeability |
