Data from: The effects of archipelago spatial structure on island diversity and endemism: predictions from a spatially-structured neutral model

Islands are particularly suited to testing hypotheses about the ecological and evolutionary mechanisms underpinning community assembly. Yet the complex spatial arrangements of real island systems have received little attention from both empirical studies and theoretical models. Here, we investigate the extent to which the spatial structure of archipelagos affects species diversity and endemism. We start by proposing a new spatially-structured neutral model that explicitly considers archipelago structure, and then investigate its predictions under a diversity of scenarios. Our results suggest that considering the spatial structure of archipelagos is crucial to understanding their diversity and endemism, with structured island systems acting both as “museums” and “cradles” of biodiversity. These dynamics of diversification may change the traditionally expected pattern of decrease in species richness with distance from the mainland, even potentially leading to increasing patterns for taxa with high speciation rates in archipelagos off species-poor continental areas. Our results also predict that, within spatially-structured archipelagos, metapopulation dynamics and evolutionary processes can generate higher diversity on islands more centrally placed than at the periphery. We derive from our results a set of theoretical predictions, potentially testable with empirical data.

岛屿尤其适合用于检验支撑群落构建（community assembly）的生态与进化机制相关假说。然而，真实岛屿系统复杂的空间排布，却鲜有实证研究与理论模型予以关注。本研究旨在探究群岛（archipelagos）的空间结构对物种多样性与特有性（endemism）的影响程度。我们首先提出一种显式纳入群岛结构的新型空间结构化中性模型（spatially-structured neutral model），随后在多种情景下对该模型的预测结果展开分析。研究结果表明，纳入群岛的空间结构，对于理解其物种多样性与特有性至关重要；结构化的岛屿系统同时扮演着生物多样性的“博物馆”与“摇篮”双重角色。这类物种分化的动态过程，可能会改变学界传统上预期的“物种丰富度随与大陆的距离增加而降低”的格局；在物种贫乏的大陆周边的群岛中，对于物种形成速率较高的类群而言，甚至可能出现物种丰富度随距离增加而升高的格局。本研究结果还预测，在空间结构化的群岛中，集合种群动态（metapopulation dynamics）与进化过程，可使位于群岛中心位置的岛屿比边缘岛屿拥有更高的物种多样性。我们基于研究结果推导出一系列理论预测，这些预测可通过实证数据加以检验。