Sky Island

Sky Island

Sky islands are mountains that are isolated by surrounding lowlands of a dramatically different environment, a situation which, in combination with the altitudinal zonation of ecosystems, has significant implications for natural habitats. Endemism, vertical migration, and relict populations are some of the natural phenomena to be found on sky islands.

The complex dynamics of species richness on sky islands draws attention from the discipline of biogeography, and likewise the biodiversity is of concern to conservation biology. One of the key elements of a sky island is separation by sheer physical distance from the other mountain ranges, resulting in a habitat island, such as a forest surrounded by desert.

Some sky islands serve as refugia for boreal species stranded by warming climates since the last ice age. In other cases, localized populations of plants and animals tend towards speciation, the same process that happens on oceanic islands such as the Galápagos Islands.