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.

岛屿是检验支撑群落构建的生态与进化机制相关假说的理想体系。然而，真实岛屿系统的复杂空间格局，却未受到实证研究与理论模型的足够重视。本研究旨在探究群岛空间结构对物种多样性与特有性的影响程度。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，随后针对多种情景探究该模型的预测结果。研究结果显示，考量群岛空间结构对于理解其物种多样性与特有性至关重要，结构化岛屿系统同时兼具生物多样性"博物馆"与"摇篮"的双重角色。这类多样化动态可能会打破学界传统认知中"物种丰富度随距大陆距离增加而降低"的预期模式，甚至在物种贫乏大陆周边的群岛中，促使高物种形成速率类群的物种丰富度呈现上升趋势。本研究同时预测，在空间结构化的群岛中，集合种群动态与进化过程可使中心位置岛屿的物种多样性高于边缘岛屿。基于上述结果，我们推导得到一系列可通过实证数据检验的理论预测。