Floristic and Ecological Characteristics of the Community with Impatiens hainanensis in Exianling Limestone Moutain, Hainan

Floristic and ecological characteristics of the community with Impatiens hainanensis were studied based on community investigation in Exianling limestone moutain, Hainan．The result showed there were 83 vascular species, subspecies, and varieties belonging to 76 genera and 46 families in 8 plots with a total area of 800 m²．The dominant families were Orchidaceae(including 16 species), Polypodiaceae(5 species), and Euphorbiaceae(4 species). The distribution types of the genera in the community were mainly Pantropic(including 18 species) and Tropic Asia (India-Malasia) (15 species). The shrub layer(including 29 species) and herb layer(45 species) were the main component of the community. There were 9 species in the liana layer. The dominant species of shrub layer, herb layer, and liana layer were Euphorbia hainanensis, Eria rosea, and Dischidia chinensis, respectively. The life form in the community was dominated by nanophanerophytes(including 57 species)．The order of the frequency distribution class was A>B>D>C>E. The A-level frequency was dominant(including 41 species). The community characteristics between I. hainanensis and Eu. hainanensis were compared. Some preliminary suggestions were also put forward on how to effectively protect I. hainanensis.