The Successional Mode In Initial Stage Of Natural Vwgetation Community Restoration In Abandoned Quarry Site Of Sibao-shan

It is well known that there are too much difficulties to recover the damaged mountain body because of mining activities, and there are few researches and practices on the vegetation's recovery. In this paper, we take abandoned quarry site of Sibao-shan was taken as the research area. Based on the site conditions and other literatures, this abandoned quarry was classified into 5 types. Typical samples were selected in each site type. The community structures, including the species composition (number of species and height), vertical and horizontal structure, life form, together with its relative environmental factors, were investigated in initial stage of natural vegetation restoration since 2006. The succession series were identified based on the community quantitative classification and ordination, as well as historical records of plant community evolution. The comunity characters were sumerized for each succession stage. This study has great significance on the vegetation restoration and reconstruction. The main conclusions are as follows:1.The species components in initial stage of natural vegetation restoration on abandoned quarry site of Sibao-shanThe herbacrous species are rich in this area. There are 55 species belonging to 45 genera and 25 families. The compositae species is consist of 36% and Gramineae species is consist of 22%, 24 plant species belonging to 23 genera and 23 families made up 42% of the total hereb species.The species of shrub are relative rare. There are only 7 species belonging to 7 genera and 4 families. There are: Vitex negundo, Rhamnus parvifolia, Lespedeza bicolor, Caragana sinica, Ziziphus jujube and Ampelopsis japonica.Gramineae species are dorminant in the annual herb plant stage during succession process. As the process continues, the degree of advantages of Gramineae species gradually reduce and down to 16.3% in the shrub stage. The number of Compositae species appear an increasing and then a decreasing trend. The number of other genera and families gradually increased.2. The species diversities in initial stage during natural restoration on abandoned quarry of Sibao-shanThe species diversity increased continuously in the initial stage during natural restoration. Even though the site types formed in the same time, the species diversity indexes have great differences among communities because of the micro-site differences. The closed species diversity indexes may need different successional time.Improving site conditions can accelerate the succession process. The complexities of community succession and the sites play an important role in the vegetation restoration, based on local circumstances improving the hydrothermal conditions should be taken. The restoration practices should be carried out according to the site conditions and succession stages.3. The succession series in initial stage of natural community restoration on abandoned quarry of Sibao-shanAccording to the WINTWINS classification and DCA ordination, and integrating the history records of the vegetation, the succession series can be divided into 3 stages: annual herb stage, perennial herb stage and shrub stage.The succession originates the pioneer species, such as Setaria viridis, Eleusine indica, with the lapse of time, perennial herbs appear. Cleistogenes hancei is the dominant species in most communities. The native species such as species of Compositae, Allium ramosum, and Cynanchum chinensis are dominant ones in better sites. The annual herb stage would last from 1 to 5 years at different site conditions. After 5~10 years growing, most of the annual herb communities develop to perennial herb communities. Meanwhile, some laigh shrubs appear in the community. The dominant is V. negundo. Latter there were more shrub species coming into and became more common. It might need 40 years for the dominant shrub layer development since its first appearing. It is very difficult to forecast how long the community climax will last, because that the shrub layer still is very simple after 50 years development and no arbor species appear at present. Without artificial measures the succession of this area will last for a long time.