The effects of under-forest economic activities (UFE) on soil water repellency, soil hydraulic properties and preferential flow pathways of karst forest soils are not fully understood. To investigate these effects, the soil physical-chemical properties including soil penetration resistance, surface shear strength and soil water repellency, as well as saturated hydraulic conductivity (K_s) and soil water retention curves (SWRCs) at depths of 0–20, 20–40, and 40–60 cm were compared between undisturbed soils affected by human trampling on forest trails formed by UFE. Disk tension infiltrometers and dye tracing experiments were also conducted to quantify the effects of UFE on the field hydraulic properties and preferential flow pathways from the center of forest trails (CF), the edge of forest trails (EF), and undisturbed forestlands (FL). Our results showed that the forest trails formed by under-forest economic activities enhanced water repellency to various degrees. The K_s of CF (37.03 mm h⁻¹) was significantly lower than that of FL (115.29 mm h⁻¹). The SWRC slopes were steeper for the CF and the EF compared to the FL in the 0–20 cm, 20–40 cm and 40–60 cm intervals, and significant differences in van Genuchten model parameters (α, n, m, θ_r, and θ_s) in the 0–20 cm layer confirm that SWRCs were largely influenced by forest trail. In addition, the averaged preferential flow fraction (PF-fr) was significantly higher for CF and EF compared to FL, while the dye coverage (DC) and uniform infiltration depths (UniFr) were significantly lower. These results indicated that preferential flow is largely enhanced by the UFE. This study provides a field-based case study illustrating the negative effects of UFE on land development and degradation.

林下经济活动（UFE）对喀斯特森林土壤拒水性、土壤水力特性和优先流路径的影响尚不完全清楚。为了研究这些影响，土壤理化性质包括土壤渗透阻力、表面剪切强度和土壤憎水性，以及0-20、20 深度的饱和导水率 ( K _s ) 和土壤保水曲线 ( SWRCs ) –40 厘米和 40-60 厘米对 UFE 形成的森林步道上受人类践踏影响的原状土壤进行了比较。还进行了圆盘张力渗透计和染料示踪实验，以量化 UFE 对现场水力特性和从森林小径中心 (CF)、森林小径边缘 (EF) 和未受干扰林地 (FL) 的优先流动路径的影响。我们的研究结果表明，林下经济活动形成的林间小径不同程度地增强了防水性。CF的K s ₍ 37.03 mm h ^-1 )显着低于FL的K s (115.29 mm h ^-1 )。在 0-20 cm、20-40 cm 和 40-60 cm 区间内，CF 和 EF的 SWRC斜率比 FL 更陡，并且 van Genuchten 模型参数（α、n、m、θ _r）存在显着差异。和θ _s）在 0-20 cm 层证实SWRC在很大程度上受到森林步道的影响。此外，与 FL 相比，CF 和 EF 的平均优先流分数 ( PF-fr ) 显着更高，而染料覆盖度 ( DC ) 和均匀渗透深度 ( UniFr ) 显着较低。这些结果表明 UFE 在很大程度上增强了优先流。本研究提供了基于实地的案例研究，说明了 UFE 对土地开发和退化的负面影响。