关键词: 祁连山, 人工林, 立地条件, 土壤水分入渗, 土壤性质

Abstract:

To reveal the differences in soil water infiltration characteristics and driving mechanisms under various sites of plantation in the Qilian Mountains， five sample plots were selected， namely Biandukou （BDK）， Dachaigou North （DCGB）， Dachaigou South （DCGN）， Shibalipu （SBLP）， and Dahuangshan （DHS）. Meanwhile， field investigations and laboratory ring-infiltrometer experiments were conducted， coupled with comprehensive analyses of soil physicochemical properties. Furthermore， three infiltration models were employed to simulate and evaluate the applicability for each plot. The results demonstrated that： （1） The soil infiltration rates across all plots followed a consistent pattern： an initial rapid decay， followed by a fluctuating decrease， and final stabilization. The stable infiltration rates ranked as DHS （5.16 mm·min^-1） > SBLP （2.4 mm·min^-1） >DCGN （2.18 mm·min^-1）> BDK （1.63 mm·min^-1）> DCGB （1.24 mm·min^-1）. The total cumulative infiltration at DHS was 3.6 times that of DCGB. （2） Soil bulk density， total porosity， soil organic carbon， and sand content were identified as the core driving factors influencing infiltration performance （P<0.01）. Stand structure （stand age， planting density） and site characteristics （land use history， disturbance intensity） jointly regulated the spatial pattern of infiltration by changing the connectivity of soil pores. （3） Compared with the Philip and Horton model， the Kostiakov model had the highest simulation accuracy for soil water infiltration across all plots （R²≥0.89）， and was more suitable for describing the soil water infiltration characteristics in the study area. The study aims to provide a theoretical foundation and practical guidance for the scientific planning of “water-based afforestation” and the optimization of eco-hydrological functions for plantations in the Qilian Mountains.

Key words: Qilian Mountains, plantation, stand conditions, soil water infiltration, soil properties