Madhuca hainanensis community species composition and interspecific association

【Objective】To explore the species composition and interspecific association of Madhuca hainanensis community, and provide scientific basis for the protection and utilization of M. hainanensis and other plant species in the community. 【Method】The M. hainanensis community in Jianfengling area of Hainan Tropical Rainforest National Park was taken as the research object, and the typical plot survey was carried out. The plant species name, diameter at breast height, height and crown width of the arborous layer, as well as plant species name, diameter at breast height（base diameter）, height and coverage of the shrub layer were recorded. Based on the analysis of the plant species composition of the community, methods such as the variance ratio method, χ² test and Spearman’s rank correlation test were used to analyze the interspecific association and stability of community structure. 【Result】Within the 0.92 ha plot, there were 7818woody plants in the M. hainanensis community, belonging to 60 families, 164 genera and 324 species, including 16 species of national key protected wild plants, 1 species of national first-class protected wild plants and 15 species of national second-class protected wild plants. The dominant families in the community were Fagaceae, Lauraceae, Theaceae, Symplocaceae and Myrtaceae, with no clear dominant species. There were 252 M. hainanensis, which were distributed across altitude ranging from 261 to1007 m. They were often found in the middle and upper slopes and ridges with sufficient light and relative drought environment. Among the top 20 species ranked by the important value in each forest layer, there were 876 main species, accounting for 46.55 % of the total plant number in the arborous layer. M. hainanensis had the highest importance value in the arborous layer（41.43%）. Gironniera subaequalis of the arborous layer had the highest importance value（34.65%）, and Ormosia semicastrata had the highest number of regeneration（237 plants）. The importance value of M. hainanensis ranked the eighth. The results of the overall association test of the main species in the M. hainanensis in Hainan showed that among the 190 species pairs formed by the main species in the arborous layer, 111species pairs showed positive association, accounting for 58.42 %. M. hainanensis showed a significantly positive correlation with Schima superba and Quercus neglecta（P＜0.05,the same below）, and a significantly negative correlation with Acronychia pedunculata. Among the 190 species pairs formed by the main species in the shrub layer, there were 184 positive associations, accounting for 96.84 %; M. hainanensis was significantly positively correlated with Ardisia quinquegona and significantly negatively correlated with Aidia oxyodonta. 【Conclusion】The structure of arborous layer and shrub layer community in the community of M. hainanensis in Jianfengling area of Hainan Tropical Rainforest National Park is relatively stable,with a rich variety of plant species and a concentrated distribution of national key protected wild plants within the community.