Influences Of Soil Environmental Factors In Bandoned Lands To Vegetation Restoration In Hilly And Gully Regions On The Loess Plateau

The dynamic of community diversity in different succession stages in the experimental area of Yan'an region was studied by using the methods of spatial-sere substituting for time-sere. The soil water, soil nutrients and bulk density of 31 sampling sites were measured. The coupling relationship between vegetation restoring succession and variety of physical and chemical property of soil was analyzed utilizing the data from year 2004 to 2005. The effect of different artificial interference measures on vegetation restoration was contrasted and analysed. The main conclusions are as follows:1. The value of niche breadth of species in early succession stage are greater than that of species in later stage and dominant species are greater than companion species.The sere was renewed through the analysis of community similarity, which could offer vegetation restoring a new theory.2. Soil bulk density decreased with the vegetation restoration, particularly that of topsoil.The vegetation restoring could enhance soil organic matter, especially that of topsoil. The organic matter distribution of soil section shows a obvious law: 0-20cm>20-40cm>40-60cm. Total N, available N and available P were correlative to soil organic matter in form of positive linear. But the change of total P as the vegetation restoration was not unobvious.Soil water content of typical herb community was the highest, shrub community was the lowest and compound layer forest was in the middle.3. According to PCA, the main influencing factors to vegetation types and succession are N , soil waterand active phosphorus. As there are relative obvious difference in different succession stage, the leading factors that influence communities structure and dynamics are different. With a review of past studies, full nitrogen is the...