Abstract:

To study the soil volume fractal dimension of 3 types at Shixiakou reservoir， Qingshuihe county， Inner Mongolia， the soils of Pinus tabuliformis， Larix gmelinii and Caragana korshinskii ×Hippophae rhamnoides were as materials， and the grassland was as control. The ring knife was used for multi-point sampling， and the soil physical and chemical properties and soil volume fractal dimension were measured. The single ring soil column method was used to observe the soil water infiltration， and the linear regression analysis was carried out between the soil volume fractal dimension and the infiltration characteristics. The results showed that different plantations in the study area could significantly improve soil nutrients， retain soil fine particles， reduce soil volume fractal dimension and improve water infiltration capacity. The soil volume fractal dimension showed grassland （2.30）， Caragana korshinskii × Hippophae rhamnoides （2.28） > Larix gmelinii （2.24）> Pinus tabulaeformis （2.18）. The initial infiltration rate， steady infiltration rate and 1 h cumulative infiltration were as follows： Pinus tabulaeformis （11.0 mm·min^-1， 1.2 mm·min^-1，116 mm） > Larix gmelinii （8.5 mm·min^-1， 0.9 mm·min^-1， 80 mm） > Caragana korshinskii × Hippophae rhamnoides mixed forest （6.2 mm·min^-1， 0.8 mm·min^-1， 62 mm） > grassland （4.7 mm·min^-1， 0.45 mm·min^-1， 51 mm）. Vegetation retained protect soil fine particles by weakening natural erosion such as surface runoff and wind erosion， so as to improve the uniformity of pore structure and texture， and then improve the infiltration capacity. In the study area， soil fractal dimension could characterize soil infiltration capacity， and Pinus tabulaeformis forest had strong water conservation capacity at Shixiakou reservoir.

Key words: Shixiakou reservoir, plantation, soil volume fractal dimension, infiltration rate

摘要：

为研究内蒙古清水河县石峡口水库3种典型人工林表层土壤体积分形维数及其与入渗特征的关系，以研究区油松、落叶松、柠条×沙棘混交林土壤为研究对象，草地土壤为对照，采用环刀进行多点取样并测定土壤理化性质及土壤体积分形维数，单环土柱法观测土壤水分入渗，并将土壤体积分形维数与入渗特征进行线性回归分析。结果表明，研究区不同人工林具有显著改善土壤养分、保留土壤细颗粒、降低土壤体积分形维数、提高水分入渗能力的作用，其中土壤体积分形维数表现为草地（2.30）和柠条×沙棘混交林（2.28）>落叶松（2.24）>油松（2.18）；初渗速率、稳渗速率、1 h累计入渗量均表现为油松（11.0 mm·min^-1，1.2 mm·min^-1，116 mm）>落叶松（8.5 mm·min^-1，0.9 mm·min^-1，80 mm）>柠条×沙棘混交林（6.2 mm·min^-1，0.8 mm·min^-1，62 mm）>草地（4.7 mm·min^-1，0.45 mm·min^-1，51 mm）。植被通过自身特征减弱地表径流和风蚀等自然侵蚀来保护土壤细颗粒，提高孔隙结构和质地均匀程度，进而改善入渗能力。在该研究区，土壤体积分形维数可以表征土壤入渗能力，油松林对于石峡口水库的水源涵养能力强。

关键词: 石峡口水库, 人工林, 土壤体积分形维数, 入渗率