Abstract:A pilot study of hydrological effects of litters layer and soil layer was carried out in three different vegetation types (Pinus tabulaeformis plantation, Larix gmelinii plantation and Robinia pseudoacacia natural secondary forests) in Dahuofang Watershed. The hydrological functions of litters layer and soil layer were quantitatively determined by immersion method and cutting-ring method. The results showed that:(1) The litter volume of three different vegetation types was about 23.20~39.11 t/hm2, which followed the order of R. pseudoacacia natural secondary forests > P. tabulaeformis plantation > L. gmelinii plantation, and the volume of semi-decomposed litter was higher than that of undecomposed litter in broad-leaved forest, while the opposite trend was observed in coniferous forest. (2) The maximum water-holding capacity and modified interception amount was 50.24~109.19 t/hm2 and 41.70~90.71 t/hm2, respectively, both of them followed the order of R. pseudoacacia natural secondary forests > P. tabulaeformis plantation > L. gmelinii plantation. (3) Semi-decomposed litter could be saturated in 8 hours and undecomposed litter reached saturation in 10 hours, the water-holding capacity had logarithmic relationship with soaking time (R2>0.91), the absorption rate changed the most within the first 1 hour of soaking, and it obviously slowed down after 4 hours, and there was a power function relationship between water absorption rate and soaking time (R2>0.93). (4) The average soil bulk density of the three vegetation types ranged from 1.10 g/cm3 to 1.25 g/cm3, total porosity was about 27.96%~30.19%. The soil effective water-holding capacity was about 21.11~29.39 t/hm2, which followed the order of R. pseudoacacia natural secondary forests > P. tabulaeformis plantation > L. gmelinii plantation. A significant power function relation between infiltration rate and infiltration fitting time was found (R2>0.90). Considering the hydrological effects of litters layer and soil layer of three different vegetation types, the water conservation function of R. pseudoacacia natural secondary forests was stronger than that of the other vegetation types, which suggested that more attention should be paid to protect and restore the natural secondary forests in the Dahuofang watershed in order to improve water conservation function of forest.