Vegetation Natural Restoration Process And Difficult Degrees In Karst Dolomite Area Of Middle Of Guizhou

Vegetation restoration of Karst dolomite area is one of the key problem of sustainable development in Southwest China. Many theories of ecology and soil science were used to discusse rules of different Karst dolomite vegetation restoration area in middle of Guizhou according these sides:community characteristics, soil physical and chemical properties, soil moisture dynamics. Then, vegetation succession stages were classified, and vegetation restoration difficulties were evaluated through statistics theories and methods. At the last, several vegetation restoration measures were put forward. The main conclusions showed that:(1) Soil thickness of research area was between4-20cm, rock fragment content was between5%-90%, and bare rock ratio was rang from4%to49%. It showed that soil thickness and rock fragment were relatively higher, however bare rock ratio was relatively lower. Soil thickness and rock fragment were main limitative factors of vegetation natural restoration.(2) Soil nutrient contents had a positive relationship with vegetation natural restoration difficult degrees. Consequently, vegetation natural restoration difficult degrees were effected by these factors.Soil nutrients should be inceased efficiently through keeping litter as much as possible.(3) During the monitoring period from July to December, the highest soil water content was forest/forest and shrub (30.32%) in July, and the lowest was grass land (17.63%) in September. The result showed soil water capacity of forest/forest and shrub was biggest. From July to October, average soil water content in research area were high, and variation rang was biggest.(4) Four vegetation natural restoration stages were classified by cluster analysis and PCA statistics way in30sample plots, such as:grass/grss+spase shrubbery, shrubbery, shrub, secondary forest/forest and shrub. According to the main limit factors, vegetation natural restoration difficulties in Karst dolomite area of middle of Guizhou were evaluated. Degrees were easy, middle difficult, rather difficult and extremely difficulty.(5) There were proper corresponding relationships between vegetation natural restoration difficulty and vegetation restoration. It showed that the relationship of vegetation-enviroment were effected and limited by each other. Several polts’ restoration grades were higher or lower than their difficulty degrees. It showed that natural vegetation restoration had greater potential or limit to develop to higher success grade in reaserch area.(6) Based on the evaluation of vegetation restoration difficulty, several restoration strategies were put forward correspondently to accelerating vegetation restoration process in research area.