The Services Function Of Biodiversity And Its Value Evaluation Of Rubber Forest In Hainan Island

The types of vegetation, the laws of succession and the changes of the biodiversity were studied by investigating the species diversity of rubber forest in time series. The biodiversities of various communities were compared. The ecological service function of biodiversity in maintaining the land fertility was also studied and discussed. The main results as follow:The succession of undergrowth, the type of vegetation and the biodiversity changed with the age of rubber forest. The main drives of succession include canopy density of rubber forest, management, climate, soil condition and the biological properties of vegetation.The biodiversity in rubber forest was different with the rainfall, the soil fertility, the age of the rubber forest and the human activities. The more plentiful the rainfall was, the more abundant the biodiversity was. The biodiversity showed declining trend with the increase of rubber forest's age. There were remarkable positive correlation between the index of biodiversity and the soil fertility.The biodiversity of the rubber forest was lower than the natural forest ecosystem's. In the past fifty years, the average amount of species in per unit area declined rapidly in Hainan Island. Till today, the average amount of species in the rubber forest per unit area only has ten kinds, which declined 80.4percent than that in 1955.With the decline of the biodiversity and its ability of maintaining the soil fertility declined, which finally result in the decline of soil fertility in rubber forest.The models of rubber forest's age and biodiversity index, biodiversity index and the soil fertility were established. The values of the ecological service function in maintaining soil fertility were evaluated by using the models.The evaluated results showed that the total value of rubber forest's biodiversity in maintaining the soil fertility in Hainan was 1.189xl010 Yuan per a year, the mean value was 2.6812x104 Yuan hm-2.a-1 and the total value of its biodiversity in maintaining the soil fertility was 8.0434xl05 Yuan hm-2 during the life cycle of rubber forest(30yaers).