Study on the community of Melastoma penicillatum in Mount Exianling, Hainan Island, China

The species composition, floral components, and characteristics of the Melastoma penicillatum Naud. community in Mount Exianling of Hainan Island were studied. A total of 37 vascular species were recorded, belonging to 33 genera and 26 families in plots with an area of 200 m². Species could be divided into seven distribution types and one subtype at the generic level, with the floristic elements mainly exhibiting tropical Asia (India-Malaysia) and pantropical distribution, which accounted for 31.03% and 24.14% of the total number of genera (excluding cosmopolitan genera), respectively. At the species level, pantropical distribution accounted for 25% of the total number of species (excluding cosmopolitan species). The shrub layer (24 species) and herb layer (9 species) were the main components of the community, with M. penicillatum Naud. dominant in the shrub layer and Blechnum orientale L.dominant in the herb layer. Only three species were distributed in the liana layer. The main life form distribution was mesophanerophyte, accounting for 40.54%. Community frequency was divided into five grades (A: 1%-20%, B: 21%-40%, C: 41%-60%, D: 61%-80%, E: 81%-100%), and followed the pattern A > B > D > C=E. The M. penicillatum Naud. community exhibited fewer plant species, sparser distribution, and more distinct layers in comparison to the Impatiens hainanensis Y. L. Chen and Euphorbia hainanensis Croizat. communities.