RT info:eu-repo/semantics/article T1 Overview of habitat history in subtropical oceanic island summit ecosystems A1 Fernández-Palacios, José María A1 Otto, Rüdiger A1 Thébaud, Christophe A1 Price, Jonathan K1 Ecosistemas K1 Islas oceánicas subtropicales K1 Ecosystems K1 subtropical oceanic island AB Summit ecosystems of oceanic islands constitute one of the most ephemeral and isolatedecosystems existing, harboring specific features that confer on their biota an outstandingdistinctness. Summits are short-lived entities, being the last ecosystems to be constructedduring the growth of the new oceanic island, and the first to vanish due either to islandsubsidence, island erosion, or both. Whereas their geological emergence/disappearanceis controlled by the volcanic/erosion activity, Pleistocene glaciations in the past millionyears, by forcing the altitudinal shift of the timberline, have also likely created or destroyedsummit ecosystems, enabling the appearance of alpine ecosystems during glacialmaxima where they were not present in interglacial periods and vice versa.On the other hand, summit ecosystems constitute islands within islands, being moreisolated from climatically similar ecosystems than the coastlines of the islands containingthem. Thus summit biota, frequently displaying a high endemicity, may originate eitherthrough dispersal from other close summit ecosystems during peak periods, or from thecolonization of the summits and later evolution to the new conditions from mid-altitudespecies of the same island. Conversely, if peak periods are absent, the disappearance ofsummit ecosystems implies the extinction or extirpation of their constitutive species. Currentsummit species have likely occupied a much larger area during glacial periods. Thusthe summits may be classified as climatic refuges. This is especially the case if glacialperiods were associated with much drier conditions on oceanic islands as is the case oncontinents. PB Institute of Arctic and Alpine Research YR 2014 FD 2014 LK http://riull.ull.es/xmlui/handle/915/18114 UL http://riull.ull.es/xmlui/handle/915/18114 LA en DS Repositorio institucional de la Universidad de La Laguna RD 27-dic-2024