厦门近岸海域无居民海岛植物区系和物种组成相似性

为摸清厦门近岸无居民海岛的主要植物群落类型, 于2017年10月调查了12个无居民海岛的植物组成, 共记录到维管束植物360种, 其中乔木78种, 小乔木或灌木109种, 藤本23种, 草本150种; 包含外来入侵植物49种, 其中恶性入侵种10种。植物区系分析表明, 厦门周边12个无居民海岛植物主要由泛热带分布种及其变型组成, 以热带、亚热带成分占主导地位, 符合其亚热带地理分布特点。总体上, 维管束植物物种相似性较高, 物种丰富度受海岛面积的影响较大, 与海岛面积存在显著的对数和幂函数关系。此外, 岸线长度、高程、周长/面积比等空间参数也对海岛物种丰富度产生一定的影响。岛屿间维管束植物物种相似性受生境多样性和岛屿边缘效应的影响, 仅吾屿可能存在小岛屿效应。

Flora and species composition similarity of the uninhabited islands in the nearshore Xiamen

To find out the main plant community types of uninhabited islands in the nearshore Xiamen, in mid-to-late October 2017, we recorded 360 vascular plant species, including 78 trees, 109 small trees or shrubs, 23 vines and 150 herbs. We also found 49 invasive alien species, 10 of which have been identified as the most serious invasive. Compositional analysis showed that vegetation in these 12 uninhabited islands were of tropical and sub-tropical types. Consistent with the subtropical geography of these islands, vegetation mainly consisted of pan-tropical species and its variants. Generally, the islands had similar species composition. Herbaceous plants dominated the flora of these islands. Power and logarithm functions best described the species-area relationships of island vascular plants. Area had the largest effect on species richness of these islands followed by other spatial parameters such as the ratio of shoreline length, elevation, and perimeter area. Habitat diversity and island edge affected similarity of vascular plant species among different islands. Except for Wuyu Isle, we did not find evidence for small island effects in these surveys.