舟山群岛主要岛屿间种子植物区系的差异及其影响因素

Difference of spermatophyte flora among main islands of Zhoushan archipelago and its influencing factors.

为探究舟山群岛中的舟山岛、普陀山、中街山列岛、桃花岛、朱家尖、梅山岛、大榭岛、金塘岛、册子岛等9个主要岛屿间种子植物区系的差异及其影响因素,应用PC-ORD 4.0、SPSS 15.0软件对各岛屿区系相似性进行聚类和排序分析.结果表明:①该群岛的种子植物种类组成有一定的地理分化:舟山岛、金塘岛、梅山岛、大榭岛、册子岛的植物区系较为相近,可以归为一组,它们与整个浙江省的分布区类型也较为相似;桃花岛、朱家尖、普陀山、中街山列岛的植物区系可以归为另一组,该组具较明显的热带亲缘特征;②除了舟山岛,各岛的珍稀濒危植物的区系关系与种子植物大致一样;③种子植物种类组成受岛屿的海拔、离大陆远近和岛屿自身的海岸线长度影响较大,岛屿总面积、山地面积、平地面积、人口数量对植物区系也有一定的影响,但山地/平地面积对其影响甚微.

Difference of spermatophyte flora among the main islands of Zhoushan archipelago and its influencing factors were studied by clustering analysis and ordination analysis with PC-ORD 4. 0 and SPSS 15.0, and these islands include mainly Zhoushan island, Putuo island, Zhongjieshan archipelago, Taohua island, Zhujiajian island, Meishan island, Daxie island, Jintang island, and Cezi island. The results were as follows, （i） there was a geographical differentiation in species composition of spermatophyte. Zhoushan island, Jintang island, Meishan island, Daxie island and Cezi island as a group had comparatively high similarity, their areal types were also similar to that of Zhejiang. The other group included Taohua island, Zhujiajian island, Putuo island and Zhongjieshan archipelago with obviously characteristic of tropical elements. （ii） The relationships of rare and endangered plants flora among these islands, except for those in Zhoushan island, were similar to those of spermatophyte flora. （ iii ）The species composition of spermatophyte in these nine islands were mainly effected by the altitude, distance from adjacent continent and coastline length. The area size, mountainous area, flatland area and total population also played a role in their flora, but the proportion of mountainous area to flatland area had little effect on it.