东山岛植被资源和物种多样性特征

调查１００块样地共１ｈｍ＾２并野外植被填困，岛上含维管植物８４科１６０属１８４种，植物区系为热带，亚热带分布成分占部属数８５．７％，对岛上１６个群落中的植物种数和个体数作了物种丰富度指数Ｄ１、多样性指数Ｄ２、优势度指数Ｄ３、均匀度Ｊ等统计，其中相思树群落上述指数依次为８．１２４、１２．５０２、２．８７８和７１．９３％；马尾松群落为８．６７６、１８．４６８、３．３５４、８３．１３％，黑松群落为８．４

Feature of species diversity and vegetational resources in Dongshan lsland

Based on field survey of 100 plots totalling l hm2 and the abundent data materials ac-quired, 184 species of vascular plants belonging to 16o genera and 84 families are idenfied inthe Dongshan Island. Analysis of floristic geographical elements indicates that the percent-age of tropical and pan-tropical elements makes up 85. 7% of the total number of genera. Itshows that the flora in the island is in consistant with the south-subtropical oceanic climate.Based on the indexes of species richness (D1 ),diversity index (D2),dominance (D3) and even-ness index (J ) in the 16 communities, the indexes are 8. 124, 12. 502, 2. 878 and 71. 93 % forAcaia cofusa, 8. 464, 11. 290, 2. 732 and 67- 61 % for Pinus thunbergii, and 8. 676, 18. 468,3. 354, 83. 13% for P. massoniana. It indlcates that these three group are most stable in theisland. The 4 indexes of arbor fluctuatc between 0.185~ 2.012 (D1); 1. 017~ 2. 628 (D2) ;0.078 ~ 1.006(D3); 11. 25% ~96. 39% (J) and of shrub between 1.083~4.468 (D1); 2.014~ 16.28 (D2); 1. 006~ 2. 687 (D3); 57. 49 % ~96. 01 %. It shows that the shrub possess moreabundant species and higher diversity and the flora in the island belongs to Fujian-Guangdong coastal mound-plain subtropical rain forest.