Taking four types of water conservation forests at the Hunhe River source as the research object

the morphological characteristics and change regularity of soil preferential flow in different water conservation forests were studied by field dyeing tracer and indoor physicochemical analysis

to reveal the formation mechanism and influencing factors of preferential flow in the process of protection and management of water conservation forest. The results showed that the infiltration depth of the soil preferential flow ranged from 30 cm to 38 cm in the four plots

and its depth was closely related to root length density. The dyeing area ratios of soil preferential flows in 0 -10 cm soil layer were 82.41%

75.44%

91.03% and 79.82%

respectively

and the dyeing area ratio of soil preferential flow decreased with the increasing of soil depth

and the dyeing area ratio of upper soil was significantly larger than that of the lower soil in the four plots. The dyeing area ratio of soil preferential flow was significantly or positively correlated with soil bulk density

total porosity

organic matter and total root length density

which all affected the occurrence degree of preferential flow

and got the multi-function relationship between the soil preferential flow dyeing area ratio and the influence index. According to the score and weight of each principal component

the comprehensive scores of soil priority flow characteristics of water conservation forests were mixed forest land (3.134) > larch forest (1.660) > cutting area (-1.946) > Korean pine forest (-2.847). The results could provide scientific basis for further study on ecological hydrological process and vegetation construction of water conservation forest at Hunhe River source.