Abstract: To understand the restoration status of vegetation on steep slopes above 35°, with the application of RS and GIS tools, 100 plots with different aspects on steep slopes of Caijiachuan watershed in Jixian County of Shanxi Province were selected. On the basis of division of site types, vegetation coverage, community restoration degree (RD) and restoration speed (RS) in different habitats of steep slope were analyzed by using the method of spatial sequence instead of time succession. The results showed that steep slopes could be divided into 3 groups of site types according to different slopes, i.e. group Ⅰ (35°-45°), group Ⅱ (45°-55°) and group Ⅲ(>55°). Coverage and biomass of groups Ⅰ and Ⅱ were obviously different from group Ⅲ(P<0.05). According to community RD and vegetation succession, recovery process was divided into early, middle and late stages. There were highest RS but lowest RD in the early stage; the moderate RD and RS in the middle stage; the slowest RS and the highest RD in the late stage. The natural restoration strategy was different for the three site types, and the RD was the highest in the early stage for both groups Ⅰ and Ⅱ, while the RD was the highest in late stage for group Ⅲ. The RD reached up to 0.8 for both groups Ⅰ and Ⅱ; for group Ⅲ, the maximum RD was only 0.5, and the effect of natural vegetation restoration was not obvious.

Key words: reclamation time, desert oasis., reclamation background, soil organic carbon storage, evolution characteristics