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.
Read more about Sky Island: Origin of The Term, Characteristics
Famous quotes containing the words sky and/or island:
“Tried by a New England eye, or the more practical wisdom of modern times, they are the oracles of a race already in its dotage; but held up to the sky, which is the only impartial and incorruptible ordeal, they are of a piece with its depth and serenity, and I am assured that they will have a place and significance as long as there is a sky to test them by.”
—Henry David Thoreau (1817–1862)
“I suggested to them also the great desirability of a general knowledge on the Island of the English language. They are under an English speaking government and are a part of the territory of an English speaking nation.... While I appreciated the desirability of maintaining their grasp on the Spanish language, the beauty of that language and the richness of its literature, that as a practical matter for them it was quite necessary to have a good comprehension of English.”
—Calvin Coolidge (1872–1933)