Study On The Trees Species Selection And Configurating Model For Soil And Water Conservation Forest In Hunan Province

It is one of the importance and difficulty points of the discipline of soil and water conservation to study on the trees species selection and configuration model for soil and water conservation forest. The soil erosion of the whole province area is 40393km2 in Hunan province. Soil erosion control is one of the primary task of ecological security construction in Hunan, but the complicated natural conditions presents great challenge in the trees Species selection and configuration model for soil and water conservation forestIt was studied on the interspecific association of dominant populations of main community types for natural secondary forest in Hunan. The relationships were researched between plant populations, plant community and its environment in the natural secondary forest. The distributions of main plant populations and its community along environmental gradient factors were definite, main types of secondary forest were divided into. The dynamic law of 12 dominant populations including masson pine and Taiwan Pine was studied with analysis of population ecology. The populations static life table were established. the succession rule of natural secondary forest in Hunan was put forward, which provide basic theory for the trees species selection and configuration model of regional soil and water conservation forest.Through analysis and investigation on soil and water loss area in Hunan, the ecological adaptation limit values to soil thickness of 19 tree species were obtained. The further research on the relationship of DBH growth of these tree species and the soil thickness with correlation Analysis, it was found that the soil thickness (especially the epipedon A+B) is the dominant factor to effect the growth of these tree species. And the eco-adapted types of 19 tree species were divided with Fuzzy Cluster Analysis.The soil and water conservation forest investigated were divided into 27 types with duplicate naming of parent materials+soil+stand, further they were divided into 7 combination groups according to the characteristics of their stands and forest soil. Water stable index permeability coefficient five regression equations about amount of soil erosion at 3 different levels of rainfall intensity had been established. They were determined 7 high yield soil and water conservation forest types and 13 soil and water conservation forest with strong anti-erodibility.11 water conservation forest models were arranged in 3 geology type areas of Shale, Granite and limestone, fixed position observation site was established there. The surface runoff and sediment production at all soil and water conservation forest models were decreased significantly different compared with the control. the results showed that terracing of sloping fields could increase the protective function of water conservation forest, especially in the initial stages of soil and water conservation forest planted.This study was expected to apply the practical technology for building soil and water conservation forest in Hunan, to contribute to the objectives of controlling the land degradation and ecological environment deterioration, reducing the sediment into the Four-water and the Dongting Lake.