系统发育多样性与系统发育结构在岛屿植物群落保护中的意义——以蜈支洲岛为例

Significance of Phylogenetic Diversity and Phylogenetic Structure in Conservation of Island Plant Communites:A Case of Wuzhizhou Island

摘要:

为探讨系统发育多样性和系统发育结构在岛屿植物群落保护决策制定中的作用，以海南三亚蜈支洲岛被子植物群系为例，分析物种丰富度和系统发育多样性的相关性。结果表明，蜈支洲岛植被可分为10种群系类型，22个样方的物种丰富度与系统发育多样性呈显著正相关，但系统发育多样性与物种丰富度对植物多样性保护优先顺序的指示有差异。森林群系的物种丰富度和系统发育多样性普遍高于灌木和草本群系，4个森林群系样方表现为系统发育结构发散，3个森林群系样方表现为系统发育结构聚集。灌木群系中露兜树（Pandanus tectorius）灌丛和草海桐（Scaevola sericea）灌丛系统发育多样性较高，草本群系中厚藤（Vitex trifolia）灌草丛系统发育多样性较高，灌木和草本群系大多倾向于系统发育结构聚集。距海或人类活动区较近的群系可能受环境过滤的作用，而远离海和人类活动区的群系主要受竞争排斥作用影响。因此，在岛屿植物多样性保护策略制定中应当综合考虑物种和系统发育维度，以及环境、演替阶段及用岛方式等因素的影响。

Abstract:

In order to understand the effects of phylogenetic diversity and phylogenetic structure on decisionmaking of island plant diversity conservation, the relationship among species richness, phylogenetic diversity and phylogenetic structure in angiosperm communities in Wuzhizhou Island, Hainan, China were studied. The results showed that there were 10 formations of vegetation in Wuzhizhou Island. Species richness was positively correlated with phylogenetic diversity in 22 plots, but the order of conservation priority indicated by phylogenetic diversity and species richness were not completely consistent. Species richness and phylogenetic diversity of forest communities were greater than those of shrub and herb communities. Four plots are phylogenetically overdispersed and three are phylogenetically clustered in forest communities. Pandanus tectorius bushland showed the highest phylogenetic diversity in shrub communities, while did Scaevola sericea bushland in herb communities. Shrub and herb communities were mostly phylogenetically clustered. Communities near to the sea or to the anthropic zones were likely to be structured by habitat filtering, which far from the sea and the anthropic zones were likely to be structured by competitive exclusion. Therefore, species and phylogenetic demensionality, together with environmental factors, succession stages and island exploitation modes, should be considered in conservation of island plant diversity.