中国沿海主要岛屿植物区系的性质及其相互关系与分布格局

通过植物区系谱、多样性指数、主坐标排序及聚类分析等方法,研究了中国沿海主要岛屿(从渤海、黄海、东海及南海海域,选取不同纬度所在地的岛屿)的植物区系性质、相互关系及分布格局,为沿海岛屿的生态保护和生物多样性保育提供依据。结果表明:(1)中国沿海主要岛屿植物区系地理成分表现出纬向分异性,温带成分比例随着纬度降低呈递减趋势,而各种热带成分比例呈递增的分布格局,这与不同海岛所处位置气候的纬向地带性基本一致;(2)不同沿海岛屿植物区系的Shannon指数(1.887~2.197)和Simpson指数(0.780~0.865)均无显著差异,而区系间Pearson相关系数(0.199~0.997)则有明显的差异;(3)通过聚类分析和主坐标排序生成的树状图和最小生成树,可将22个岛屿划分为5个集合,揭示了沿海岛屿植物区系属的类似性和南北纬度分布格局。

Phytogeographical Patterns,Relationships and Characters of Coastal Islands in China

To provide the basis of ecology and biodiversity conservation in coastal islands,We conducted floristic spectrum,diversity index,principal coordinate analysis and cluster analysis to reveal distribution patterns and floristic relationships of coastal islands (chose from Bohai,Huanghai,Donghai and Naihai in different latitude area) in China.Results showed that:(1) with the decrease of latitude,a decreasing trend can be observed on the proportions of temperate elements at genus-level,while those of tropical elements showed contrary patterns,which may be strongly corelated with their different ecological characters and energy distribution;(2) Compared with other coastal islands,floristic Shannon index (1.887-2.197) and Simpson index (0.780-0.865) have no obvious difference.Pearson correlation is significant at the 0.01 level by correlation analysis,and the coefficients are between 0.199 and 0.997.(3) Two-dimentional scatter plot of PcoA and cluster dendrogram based on the floristic spectrum demonstrated floras of 22 coastal islands were divided into 5 groups,North-south latitude distribution pattern and similarity of the floristic of 22 coastal islands in China was revealed accordingly.