欧李林龄对不同坡面土壤水分特征的影响

Effect of Cerasus Humilis Stand Age on Soil Moisture Characteristics of Different Slopes

[目的]研究不同林龄欧李在生长季(4—9月)对坡面土壤水分动态及时间稳定性的影响,为欧李在黄土高原丘陵沟壑区小流域综合治理中的合理配置提供科学依据。[方法]基于对欧李不同坡度标准径流小区土壤水分长期定位观测,利用Origin Pro软件对土壤水分进行计算分析。[结果]①欧李栽植后,土壤储水量有所下降,但不明显,有逐渐恢复的态势,不同坡度土壤储水量差异不明显。②在生长季,5°和10°小区0—40 cm和100 cm以下土层土壤含水量较低,表现为弱变异,40—100 cm土层土壤储水量较高,表现为中等变异;15°小区0—100 cm土层土壤水分年际之间相差较大,120 cm以下土层的土壤含水量较高,均处于中等变异区间。③随着欧李林龄增加,不同坡度坡面土壤水分的时间稳定性逐步增强,其中15°小区最明显。[结论]结合欧李在坡面的生长状况,研究认为“欧李+水平阶”的坡面治理模式在黄土高原沟壑区10°以下坡面上配置有一定优势。

[Objective]The influence of different forest ages on the soil moisture dynamics and time stability of different slopes during the growing season(April-September)was determined in order to provide a scientific basis for the rational use of Cerasus humilis in the comprehensive management of small watersheds in hilly and gully areas of the Loess Plateau.[Methods]Based on long-term positioning observations of soil moisture in standard runoff plots with different slopes,the relevant parameters of soil moisture were calculated and analyzed using Origin Pro software.[Results]①Soil water storage decreased after tree planting,but the decrease was not significant.There was a gradual recovery trend,but differences in soil water storage on different slopes were not significant.②During the growing season,soil water contents in the 0—40 cm layer and below 100 cm in the 5°and 10°slope plots were low,and the coefficient of variation showed weak variation.Soil water storage in the 40—100 cm soil layer was high,and the coefficient of variation showed moderate variation.Soil water storage in the 0—100 cm layer for the 15°slope plot exhibited a large difference between the two study years.The soil water content below 120 cm was high and exhibited medium variation.③The temporal stability of soil water gradually increased with increases in the growth and age of Cerasus humilis,and were most obvious for the 15°slope plot.[Conclusion]The slope treatment model of“Cerasus humilis+level bench”has some advantages on slopes of less than 10°in hilly and gully areas of the Loess Plateau,depending on the growth status of Cerasus humilis.