黄土陡坡人工植被下土壤表层的水文效应

Soil Surface Hydrological Effects of Artificial Vegetation on Loess Steep Slopes

[目的]探讨栽植坡度、坡向对绿化陡坡土壤表层水文效应的影响,为黄土陡坡植被恢复过程中水资源的有效利用提供科学依据。[方法]在干旱半干旱区选择46°~55°和56°~65°两个陡坡级的阴坡、半阴坡、阳坡、半阳坡4种坡向绿化8 a的乔灌木陡坡,测定0—40 cm土层的土壤基本性状、持水量和渗透性能,分析各土壤因子和地形因子的关系。[结果]①坡度和坡向立地因子之间交互作用对0—40 cm土层土壤容重、质量含水量、总孔隙度、最大持水量有显著影响(p<0.05),对0—20 cm土层土壤毛管孔隙度、毛管持水量有显著影响(p<0.05),其他因子影响均不显著(p>0.05)。②不同坡度间,最大持水量表现为:46°~55°>56°~65°陡坡;平均渗透速率则表现为:56°~65°>46°~55°陡坡;同时不同坡向间,最大持水量表现为:阳坡(522.42 t/hm^(2))>半阳坡(505.03 t/hm^(2))>阴坡(502.27 t/hm^(2))>半阴坡(496.15 t/hm^(2));土壤平均渗透速率表现为阳坡(0.79 mm/min)>半阳坡(0.59 mm/min)>阴坡(0.42 mm/min)>半阴坡(0.30 mm/min)。③双因素方差分析表明,坡度级和坡向的双因素交互作用对陡坡的水文特征影响最大。[结论]46°~55°陡坡的土壤基本性状优于56°~65°陡坡,而阳坡和半阳坡的水源涵养能力高于阴坡和半阴坡。

[Objective]The influences of slope inclination aspect on hydrological characteristics in the soil surface layer and on the greening steep slopes were studied in order to provide a basis for the effective use of water resources in the process of vegetation restoration on steep loess slopes.[Methods]We conducted a comprehensive study on two steep slopes with inclinations of 46°~55°and 56°~65°located in arid and semi-arid regions.These slopes were categorized into four slope orientations:shady slopes,semi-shady slopes,sunny slopes,and semi-sunny slopes.Arboriculture and shrubbery greening initiatives were implemented on these steep slopes over an 8-year period.We conducted extensive analyses on basic soil properties,water-holding capacity,and infiltration of the 0—40 cm soil layer.Furthermore,we explored the intricate relationship between various soil factors and terrain factors.[Results]①The interaction between slope classes and slope orientations stand factors had a significant effect(p<0.05)on soil bulk weight,mass water content,total porosity,and maximum water holding capacity in the 0—40 cm soil layer,and a significant effect(p<0.05)on soil gross tubular porosity and gross tubular water holding capacity in the 0—20 cm soil layer,However,these differences were not statistically significant(p>0.05)under alternative conditions.[HJ]②Maximum water-holding capacity was found to be higher for the 46°~55°steep slopes than for the 56°~65°steep slopes.Conversely,the average infiltration rate was higher for the 56°~65°steep slopes than for the 46°~55°steep slopes.Sunny slopes had the highest maximum water-holding capacity(522.42 t/hm^(2)),followed by semi-sunny slopes(505.03 t/hm^(2)),shady slopes(502.27 t/hm^(2)),and semi-shady slopes(496.15 t/hm^(2)).Similarly,the average soil infiltration rate was highest for sunny slopes(0.79 mm/min),followed by semi-sunny slopes(0.59 mm/min),shady slopes(0.42 mm/min),and semi-shady slopes(0.30 mm/min).③A two-factor analysis of variance revealed that the interaction between slope class and slope aspect had the most significant impact on the hydrological characteristics of steep slopes.[Conclusion]Basic soil properties were better for 46°~55°steep slopes than for 56°~65°steep slopes.Moreover,sunny and semi-sunny slope orientations exhibited greater water-holding capacities than shady and semi-shady slope orientations.