Scientists’ warning – The outstanding biodiversity of islands is in peril

作者：José María Fernández‐Palacios, Holger Kreft, Severin D. H. Irl, Sietze J. Norder, Claudine Ah‐Peng, Paulo A. V. Borges, Kevin C. Burns, Lea de Nascimento, Jean-Yves Meyer, Elba Montes, Donald R. Drake · 发表于：Global Ecology and Conservation · 年份：2021 · DOI：10.1016/j.gecco.2021.e01847 · 被引用次数：372 · 研究领域：Animal Ecology and Behavior Studies、Species Distribution and Climate Change、Plant and animal studies

Despite islands contributing only 6.7% of land surface area, they harbor ~20% of the Earth's biodiversity, but unfortunately also ~50% of the threatened species and 75% of the known extinctions since the European expansion around the globe. Due to their geological and geographic history and characteristics, islands act simultaneously as cradles of evolutionary diversity and museums of formerly widespread lineages-elements that permit islands to achieve an outstanding endemicity. Nevertheless, the majority of these endemic species are inherently vulnerable due to genetic and demographic factors linked with the way islands are colonized. Here, we stress the great variation of islands in their physical geography (area, isolation, altitude, latitude) and history (age, human colonization, human density). We provide examples of some of the most species rich and iconic insular radiations. Next, we analyze the natural vulnerability of the insular biota, linked to genetic and demographic factors as a result of founder events as well as the typically small population sizes of many island species. We note that, whereas evolution toward island syndromes (including size shifts, derived insular woodiness, altered dispersal ability, loss of defense traits, reduction in clutch size) might have improved the ability of species to thrive under natural conditions on islands, it has simultaneously made island biota disproportionately vulnerable to anthropogenic pressures such as habitat loss, ove...