Sky island - Definition and Overview

For the fantasy novel by L. Frank Baum, see Sky Island.

Sky islands are mountains in ranges isolated by valleys in which other ecosystems are located. As a result, the mountain ecosystems are isolated from each other, and species can develop in parallel, as on island groups such as the Galapagos.

The best known examples of sky islands is an area at the northern end of the Sierra Madre Occidental, including parts of New Mexico, Arizona, Chihuahua and Sonora, on the United States-Mexico border.

Other sky islands can be found in the Great Basin, Venezuela, and in Africa. Some Asian examples include Mt. Victoria (3050 m) in central Myanmar, Fan Si Pan (3140 m) in northernmost Vietnam, and the mountains of central Taiwan; these mountains all hold isolated outposts of Palearctic flora in the otherwise tropical Indomalayan flora region.

External links

• Sky Island Alliance homepage (http://www.skyislandalliance.org/)
• USGS page on Southwestern sky islands (http://biology.usgs.gov/s+t/frame/r119.htm)