Abstract:
Objective To reveal the succession of vegetation in Neilingding Island, and provide a scientific basis for protection of Artocarpus hypargyreus, a rare and endangered species endemic to China.
Method Method in community ecology was used to survey the sample plots of A. hypargyreus community in Neilingding Island, Guangdong. The community composition and structure, characteristics of geographical components and species diversity were analyzed, and were compared to those of other three plant communities in tropic or mid-subtropical regions.
Result A total of 73 species of vascular plants belonging to 61 genera of 40 families were discovered in the A. hypargyreus community.Among them, 4 species of pteridophyta belong to 4 genera of 6 families, and 69 species of seed plants belong to 57 genera of 36 families. Tropical genera (98.18%) occupied a foremost position in this community which shows a transitional property that range from south subtropical to tropical regions. The stratification of the community was obvious: the dominant populations in the arborous layer mainly were Pterospermum heterophyllum, A. hypargyreus, Litsea monopetala and Machilus chekiangensis, with the important values of 43.86, 31.64, 12.75 and 10.39 respectively, the dominant population in the shrub layer mainly were Microcos paniculata and Psychotria rubra, and the lianas were abundant among the layers. The dominant populations in this community had clustering distribution pattern, and were characterized by stumpage of level Ⅱ (DBH < 2.5 cm) and level Ⅲ (2.5 cm≤DBH < 7.5 cm), indicating that they belonged to the increasing population except the A. hypargyreus population was declining. In this community, Simpson diversity index (E) was 0.95, Shannon-Wiener diversity index (H) was 3.27, and Pielou evenness index (EH) was 0.84.
Conclusion The A. hypargyreus community in Neilingding Island is a south subtropical evergreen broad-leaved forest at the middle stage of succession.