By using the combined grid and line method in vegetation investigation

vegetation succession in the hill and gully area of western Shanxi Province was studied by a case study of Tuqiaogou small watershed in Fangshan County of Shanxi Province.Results showed that Chinese pine and silver chain(importance value:117.34 and 69.96

respectively)are predominant species of the tree layer in the area.Lespedeza

C.microphylla

and seabuckthorn(importance value:169.45

74.05

and 36.92

respectively)are predominant species of the shrub layer.The herblayer is made of composite and gramineous plants(importance value:126.18and 82.63

respectively).Analysis of comparison and clustering showed that community types are pine cluster and lespedeza cluster in Tuqiaogou small watershed.Vegetation succession list is from bare groud

grassplot

shrub

pioneer trees to co nifer.Succession direction of the whole watershed is toward the silver chain community

Chinese pine community

elmcommunity

arborvitae community

and elmsilver chain mixed community.