Context Although there have been methodological advances in the analysis of biodiversity and landscape properties, most studies in landscape ecology primarily explore whether certain landscape properties, such as island area and isolation, have universal effects on species-centric measures. Objectives We assessed how landscape variables drive species richness, phylogenetic diversity (PD), and phylogenetic community structure. Moreover, we explored the dominant processes structuring plant community assembly, including phylogenetic community structure. Methods We used plant data from 235 uninhabited islands in the western and southern seas, South Korea. Species richness, Faith’s PD, and standardized effect size of mean pairwise phylogenetic distance (SES.MPD) were quantified for three plant groups, all, woody, and herbaceous plants for each island. Island area, distance from mainland, habitat heterogeneity, and structural connectivity were also calculated to examine the relationships between indices of plant diversity and community structure. Results The relative importance of landscape variables differed among indices of diversity and community structure as well as among plant groups. Island area and distance from mainland were the main drivers of species richness and PD across plant groups, whereas distance from mainland significantly affected community structure measured by SES.MPD. We found that the community structure in islands farther from mainland showed phylogenetic clustering patterns driven by niche-based deterministic processes across the three plant groups. Conclusions We found that community structure analysis provides more information related to ecological processes and assembly mechanisms than diversity indices alone. Therefore, we recommend that community structure analysis with plant diversity should be implemented as an additional measure of biodiversity for landscape ecology and for conservation planning in island ecosystems.

中文翻译：

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韩国无人岛景观变量对植物多样性和系统发育群落结构的相对重要性

背景 尽管在分析生物多样性和景观特性方面取得了方法上的进步，但大多数景观生态学研究主要探索某些景观特性，如岛屿面积和隔离，是否对以物种为中心的措施具有普遍影响。目标我们评估了景观变量如何驱动物种丰富度、系统发育多样性 (PD) 和系统发育群落结构。此外，我们探索了构建植物群落组装的主要过程，包括系统发育群落结构。方法 我们使用来自韩国西部和南部海域 235 个无人居住岛屿的植物数据。物种丰富度、Faith's PD 和平均成对系统发育距离 (SES.MPD) 的标准化效应大小被量化为三个植物组，每个岛屿的所有植物、木本植物和草本植物。还计算了岛屿面积、与大陆的距离、栖息地异质性和结构连通性，以检查植物多样性指数与群落结构之间的关系。结果景观变量的相对重要性在多样性指数和群落结构以及植物群之间存在差异。岛屿面积和距大陆的距离是植物群中物种丰富度和 PD 的主要驱动因素，而距大陆的距离显着影响 SES.MPD 测量的群落结构。我们发现远离大陆的岛屿中的群落结构显示出由三个植物群中基于生态位的确定性过程驱动的系统发育聚类模式。结论我们发现群落结构分析比单独的多样性指数提供了更多与生态过程和组装机制相关的信息。因此，我们建议将植物多样性的群落结构分析作为景观生态学和岛屿生态系统保护规划的生物多样性的附加措施。