Speaker

Patrick Weigelt (Universität Göttingen, Germany)

Abstract

Islands are renowned as evolutionary laboratories and host many species that are not found elsewhere. 31% of all vascular plant species are native to islands, and 21% are island endemics. Island endemics are nonrandomly distributed within the tree of life, with 17 families and 1,702 genera being entirely endemic to islands. Islands are also of great conservation concern, with many of their endemic species currently threatened or extinct. Among all assessed island endemic species, 51% are threatened, and 55% of all documented global plant extinctions have occurred on islands. In addition, island assemblages are highly altered due to the introduction of alien species, with extreme cases where alien species numbers exceed numbers of native species. Anthropogenic changes to island floras do not only threaten biodiversity but also compromise island biogeographic research. Prominent island biogeographic patterns like the island species area relationship, island syndromes or disharmony as well as diversification and extinction dynamics may be obscured by anthropogenic change. Urgent measures including habitat restoration, invasive species removal and ex situ programs are needed to protect the uniqueness of the world’s island floras.