Abstract: We examined the impacts of shrub community roots on soil antiscourability in alpine gorge area in Jiajin Mountains of Sichuan Province. The Ward cluster analysis method was employed to divide communities into different types. Field sampling and undisturbed soil erosion experiment were conducted to analyze the root distribution characteristics of different community types and their effects on soil erosion resistance. The results showed that shrub communities in Jiajin Mountains could be divided into four types, with root length density and root surface area density following the order ofQuercus semicarpifolia+Salix wallichianaFragaria vesca community (type Ⅳ) > Rhododendron vernicosumLigularia fischeri community (type Ⅰ) >R. tatsienense+Cotoneaster subadpressusPteridium aquilinumvar. latiusculumcommunity (type Ⅱ) >Q. semicarpifolia+C. subadpressusP. aquilinumvar. latiusculum community (type Ⅲ); (2) Each community was dominated by roots of <1 mm diameter, while community type Ⅳ had the highest root biomass; (3) Results of the undisturbed soil erosion test showed that soil sand content in each community type decreased over time and then tended to be gentle, while the soil antiscourability coefficient was fluctuatingly increased with erosion time. The soil of type Ⅳ had stronger antiscourability; (4) Results of correlation analysis showed that roots of 0.5-1 mm diameter, total root weight density and total root volume were the main factors influencing soil anti-scourability of shrubs in Jiajin Mountains. Our results provide a basis for studies of soil erosion pattern of shrub community in the alpine gorge area.

Key words: soil anti-scourability, shrub community, root system, Ward clustering, alpine gorge.