The establishment of plantation forests typically results in a gradual depletion of soil fertility a phenomenon that may further impair the soil's water conservation function This study conducts a system atic analysis of the differences in soil water retention and hydraulic conductivity between Larix kaempferi plantation forests and adjacent natural secondary forests in the Xiaolongshan region of Gansu Province to assess the specific impacts of plantation forest establishment on soil water conservation capabilities Although the two forest types differ in soil particle composition both are characterized by silty clay loam soils with robust water retention properties However the soil of the Larix kaempferi plantation forests exhibits significantly lower organic matter content P<0 001 and a higher bulk density P<0 01 compared to that of the natural secondary forests These disparities in soil texture particularly in structural differences result in the plantation forests having considerably lower saturated water content P<0 001 non-capillary water holding capacity P<0 001 and saturated hydraulic conductivity than the natural secondary forests Considering the relative degradation of the water conservation function in the soil of Larix kaempferi plantation forests it is recommended that plantation forests no longer serving production functions should gradually undergo naturalization transformations through enhancing the accumulation of soil organic matter to progressively restore and enhance the soil's water conservation capabilities