Data from: Pleistocene extinctions as drivers of biogeographical patterns on the easternmost Canary Islands

Subtropical islands are often viewed as refuges where Quaternary climatic shifts driving global episodes of extinction were buffered. Island biodiversity, however, may have been impacted by climatic fluctuations at local scales, particularly in spatially heterogeneous island systems. In this study, we generated a conceptual framework for predicting the potential impact of Pleistocene extinctions on the biogeographical pattern of the Canarian spermatophyte flora, with a focus on the easternmost Canarian islands (ECI). Then, we performed an exhaustive bibliographic revision (270 studies) to examine whether taxonomic, phylogenetic and phylogeographical data support our predictions. Although molecular information is limited for many lineages, the available data suggest that the majority of extant ECI plant taxa may be the result of relatively recent (<1 Ma) dispersal from surrounding insular and mainland areas. Different lines of evidence are compatible with the idea of a Pleistocene period of frequent lineage extirpation on ECI. Extinction may thus have provided new ecological opportunities for recent (re)colonization, with some cases of recent establishment mediated by facilitation. Considering background extinction on ECI, we describe five general patterns of colonization for Canarian plant lineages. In addition to factors related to island ontogeny and long‐distance dispersal, we suggest that Pleistocene extinctions may have significantly contributed to extant biogeographical patterns in the Canarian archipelago, such as the biased distribution ranges of island plants and the low endemic richness on ECI. This new scenario provides testable hypotheses for future studies dealing with the phylogeography, taxonomy and conservation of terrestrial biodiversity on the Canarian islands, and possibly, on other near‐shore islands.

亚热带岛屿常被视为避难所，可缓冲驱动全球灭绝事件的第四纪气候波动。然而，岛屿生物多样性或已受到局地尺度气候波动的影响，在空间异质性较高的岛屿系统中尤为显著。本研究构建了一套概念框架，用以预测更新世灭绝事件对加那利群岛种子植物区系（spermatophyte flora）生物地理格局的潜在影响，研究重点聚焦于加那利群岛最东端岛屿（ECI）。随后，我们开展了一项涵盖270项研究的全面文献综述，以检验分类学（taxonomic）、系统发育（phylogenetic）及系统地理学（phylogeography）数据是否支持本研究提出的预测。尽管多数演化支的分子数据仍较为有限，但现有数据表明，现存的绝大多数ECI植物类群或源自距今相对较近（<1百万年）的周边岛屿与大陆地区的扩散事件。
不同证据均支持ECI在更新世时期存在频繁演化支区域灭绝事件的观点。因此，灭绝事件或许为近期的（再）定殖提供了新的生态机遇，部分类群的近期定植正是通过促进作用实现的。
结合ECI的背景灭绝情况，我们总结了加那利群岛植物演化支的五种普遍定殖模式。除了与岛屿发育历程和长距离扩散相关的因素外，我们认为更新世灭绝事件或对加那利群岛现存的生物地理格局产生了显著影响，例如岛屿植物的分布范围偏倚以及ECI较低的特有物种丰富度。
这一新研究框架为未来针对加那利群岛乃至其他近岸岛屿陆地生物多样性的系统地理学、分类学及保护研究提供了可检验的假说。