The Preliminary Research On Managemental Countermeasure Of The Rocky Desertification Region In Yongzhou City Of Hunan Province

Yongzhou City is located in Southwest of Hunan Province and belongs to subtropical monsoon climate. Yongzhou City is one of exemplary representatives on rocky desertification regions in Hunan Province. During the time of2010-2012, vegetation forms were investigated carefully on rocky desertification regions in Yongzhou City by author. The results are composed by3parts which are detailed analysis and investigation. They are composition of plant species, vegetation forms and plant coenotypes, as well as reproducing tree species and growing patterns.There are513vascular plant species on rocky desertification regions including127families and330genera. Among them, there are14species of pteridophyte including11families and12genera, as well as499species of seed-bearing plants including116families and308genera. In the seed-bearing plants, there are4species of gymnospermae including3families and4genera, as well as there are495species of angiosperm including113families and314genera.There are2vegetable forms on the rocky desertification regions in Yongzhou City. That is to say mingled forest of evergreen and broadleaved leaves and broadleaved deciduous forest. Among the mingled forest of evergreen and broadleaved leaves, there are5plant coenotypes. They mean that Cyclobalanopsis gracilis mingled forest of broadleaved deciduous, Osmanthus fragrans mingled forest of broadleaved deciduous, Quercus oxyphylla mingled forest of broadleaved deciduous, Castanopsis jucunda mingled forest of broadleaved deciduous and Cyclobalanopsis glauca mingled forest of broadleaved deciduous. Among the broadleaved deciduous forest, there ate9plant coenotypes. They mean that Quercus chenii forest, Quercus variabilis forest, Quercus acutissima and Quercus aliena forest, Gleditsia sinensis and Lagerstroemia caudata forest, Cladrastis platycarpa forest, Carya hunanensis forest, Pistacia chinensis forest, Cornus wilsoniana and Ulmus parvifolia forest, Cornus wilsoniana forest.Combined with present situation of the rocky desertification regions and selection principles of trees in Yongzhou City, some tree species are considered according to provenance, seed, grow seedlings difficulty. Climate tree species are suitable to growing on the rocky desertification regions and climate vegetation are recovered. They are evergreen tree species and deciduous tree species. Evergreen tree species include Cyclobalanopsis oxyodon and Cyclobalanopsis gracilis. Deciduous tree species include Quercus variabilis, Quercus acutissima, Cladrastis platycarpa, Pistacia chinensis, Swida wilsoniana, Celtis sinensis, Pteroceltis tatarinowii and other species. Ecological forests are growing. Timber forests and other trees of economic value are not managed. But in the foot of Moutain, some fruit trees are suitable to manage. Seal and ban forest is a major measure on the rocky desertification in Yongzhou City. Some climate tree species should be managed in the serious regions and area of lacking mother tree. Vegetational recoveration of limestone is a long-term and slow process. As well as vegetation are protected seriously.