三峡库区4种库岸边坡的植被根系固土效应研究

发布时间：2018-08-07 13:28

【摘要】：选择三峡库区无植被、草丛、灌丛及林木覆盖的4种边坡,测量了土壤表层(0—15cm)的抗冲和抗蚀增强值,并以10cm为单位分层获取了土壤表层(0—50cm)的根长密度、根系生物量、土壤含水量、田间持水量、抗剪强度等指标。结果表明:(1)灌丛边坡的抗冲与抗蚀增强值均最大,显著高于草丛和林木边坡;灌丛边坡的抗剪强度值较大,裸地在10—20cm的土层急骤增大,然后随土层深度逐渐减小,林地在最深层有着最大值。(2)3种有植被覆盖边坡的根系均集中在30cm的表层,根长密度随着土层深度而减小;草丛和灌丛的根生物量在各层间变化不明显,林木根生物量随土层加深而迅速减小;(3)裸地的土壤含水量随着土层深度而急剧增加,林木则呈相反趋势,草丛和灌丛的变化较为平缓;灌丛的田间持水量在各层间基本保持一致,草丛和林木随着土层的加深而降低,裸地的表层田间持水量较大;(4)灌丛边坡的土体最稳定,各指标在土壤各层间较为稳定,林木和草丛边坡也有一定的稳定性,无植被覆盖的边坡稳定性最差。
[Abstract]:Four kinds of slopes without vegetation, grass, shrub and forest cover were selected in the three Gorges Reservoir area. The erosion and erosion enhancement values of soil surface layer (0-15cm) were measured, and the root length density and root biomass of soil surface layer (0-50cm) were obtained by stratification of 10cm. Soil moisture content, field water holding capacity, shear strength and so on. The results are as follows: (1) the scour and erosion resistance of shrub slope is the largest, which is significantly higher than that of grass and forest slope, the shear strength of shrub slope is larger, the bare land increases rapidly in the soil layer of 10-20cm, and then decreases gradually with the depth of soil layer. (2) the root system of three kinds of vegetation covered slope is concentrated in the surface layer of 30cm, and the root length density decreases with the depth of soil layer, and the root biomass of grass bush and shrub is not obvious change among different layers. (3) the soil moisture content of bare land increased sharply with the depth of soil layer, but the forest tree showed the opposite trend, and the change of grass and shrub was relatively gentle. The field water holding capacity of shrub is basically the same among the layers, the grass and trees decrease with the deepening of soil layer, and the field water holding capacity of the surface layer of bare land is larger. (4) the soil mass of shrub slope is the most stable, and each index is more stable among the soil layers. Forest and grass slopes also have some stability, and the slope without vegetation cover is the worst.
【作者单位】：河南科技大学林学院;临沂大学山东省水土保持与环境保育重点实验室;西南大学三峡库区生态环境教育部重点实验室;
【基金】：国家自然科学基金(31500371;31370443) 河南科技大学博士科研基金(09001685)
【分类号】：S157

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