School of Geography, Earth and Environmental Sciences, University of Birmingham, B15 2TT Birmingham, United Kingdom.
Birmingham Institute of Forest Research, University of Birmingham, B15 2TT Birmingham, United Kingdom.
Proc Natl Acad Sci U S A. 2019 Jun 18;116(25):12337-12342. doi: 10.1073/pnas.1818190116. Epub 2019 May 30.
The increase in species richness with island area (ISAR) is a well-established global pattern, commonly described by the power model, the parameters of which are hypothesized to vary with system isolation and to be indicative of ecological process regimes. We tested a structural equation model of ISAR parameter variation as a function of taxon, isolation, and archipelago configuration, using a globally distributed dataset of 151 ISARs encompassing a range of taxa and archipelago types. The resulting models revealed a negative relationship between ISAR intercept and slope as a function of archipelago species richness, in turn shaped by taxon differences and by the amount and disposition of archipelago area. These results suggest that local-scale (intra-archipelago) processes have a substantial role in determining ISAR form, obscuring the diversity patterns predicted by island theory as a function of archipelago isolation. These findings have implications for the use and interpretation of ISARs as a tool within biogeography, ecology, and conservation.
岛屿面积与物种丰富度（ISAR）的增加是一个既定的全球模式，通常用幂模型来描述，该模型的参数被假设随系统隔离而变化，并能指示生态过程的状态。我们利用一个全球性分布的数据集，其中包含 151 个 ISAR 数据集，涵盖了多种分类群和群岛类型，测试了 ISAR 参数变化与分类群、隔离度和群岛结构之间的结构方程模型。结果模型揭示了 ISAR 截距和斜率与群岛物种丰富度之间的负相关关系，这反过来又受到分类群差异以及群岛面积的数量和分布的影响。这些结果表明，局部尺度（群岛内）的过程在确定 ISAR 形态方面起着重要作用，从而掩盖了岛屿理论预测的多样性模式，这是由群岛隔离度决定的。这些发现对在生物地理学、生态学和保护生物学中使用和解释 ISAR 作为一种工具具有重要意义。
