Close-to-nature Concept For Restoration And Management Of Tropical Secondary Forest On Hainan Island

Due to the daily degradation of environment and the related ecological problem, ecological issues are now being paid more and more attention. Forestry as an important ecological sector now is shifting its task from timber production to multi-purpose forestry. On Hainan Island, the tropical secondary forest consisting of large parts of the forest is significant to the ecological and economical development on Hainan Island. However, the tropical secondary forest here is in poor condition which is an urgent issue for the forestry sector on Hainan Island. Supported by the National Natural Science Foundation of China (30671679) and the National Key Technology R&D Program in the 11th Five year Plan of China (2006BAD03A04-03), the research was conducted to study the sturcutre and dynamics of tropical nature forest in different secussion stages in order to find the possible restoration approach for the degraded secondary forest.In this study, two types of secondary forest of different successiong stage and primary forest were selected to conduct the comparision study in terms of horizontal structure, vertical structure, species structure, regeneration status, forest dynamics as well as soil proprety. The result show regarding to horizontal structure, vertical structure and species structure, the two secondary forest show no significant difference while primary forest is significant different from the two secondary forests. In terms of forest dynamics, the rate of growth of SF1 is larger than that of SF2 indicating the high growth rate in the early succession stage. For the soil property, there was almost no significant difference between SF1 and PF, while significant difference was observer between SF1 and SF2 as well as PF.According to the theory of close to nature forestry and the current condition of the different secondary forests, two different forest development types were made. For SF1, the objectives of the forest development types are protective function and timber production. The dominate tree species in the future stands are Lithocarpus corneus, Syzygium cumini and Castanopsis hainanensis. The target diameter of Lithocarpus corneus is 50cm and the felling age is more than 50; the final felling age of Syzygium cumini is more than 50 with the target diameter 45-50cm; the target diameter of Castanopsis hainanensis is 50-70cm with final felling age more than 50; For the older secondary forest, the main aims of the forest development type is also timber production and protective function. In the future stand, the dominate tree species are Cinnamomum porrectum, Syzygium cumini, Phoebe zhennan, Liquidambar formosana. Cinnamomum porrectum has the target diameter of 40 with felling age more than 50; the final felling age of Syzygium cumini is more than 50 and its target diameter is 70-80cm, the target diameter of Phoebe zhennan is 60-70 cm with final felling age of more than 60. The target diameter of Liquidambar formosana is 45 cm with final felling age more than 20.