Sky island
Sky islands are
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 physical distance from the other mountain ranges, resulting in a habitat island, such as a forest surrounded by desert.
Some sky islands serve as
Etymology
Herpetologist Edward H. Taylor presented the concept of "Islands" on the Mexican Plateau in 1940 at the 8th American Scientific Congress in Washington, D. C. His abstract on the topic was published in 1942.[2]
The sky island concept was later applied in 1943 when Natt N. Dodge, in an article in Arizona Highways magazine, referred to the Chiricahua Mountains in southeastern Arizona as a "mountain island in a desert sea".[3]
In about the same era, the term was used to refer to high alpine, unglaciated, ancient topographic landform surfaces on the crest of the
The term was popularized by nature writer Weldon Heald, a resident of southeastern Arizona. In his 1967 book, Sky Island, he demonstrated the concept by describing a drive from the town of
Around the same time, the idea of mountains as islands of habitat took hold with scientists and has been used by such popular writers as
Characteristics
The
Some more northerly examples are the
Some montane species apparently evolved within their current range, adapting to their local environment, such as the Mount Lyell shrew.[10] However, it has also been noted that some isolated mountain ecosystems have a tendency to lose species over time, perhaps because small, insularized populations are vulnerable to the forces of extinction, and the isolation of the habitat reduces the possibility of colonization by new species.[6] Furthermore, some species, such as the grizzly bear, require a range of habitats. These bears historically made use of the forests and meadows found in the Madrean sky islands, as well as lower-elevation habitats such as riparian zones. (Grizzlies were extirpated from the region in the 20th century.)[11] Seasonal movements between highland and lowland habitats can be a kind of migration, such as that undertaken by the mountain quail of the Great Basin mountains. These birds live in high elevations when free of snow, and instead of migrating south for the winter, they migrate down.[12]
Confusing the matter somewhat is the potential for an archipelago of sky islands or even the valleys between them to act not only as a barrier to biological dispersal, but also as a path for migration. Examples of birds and mammals making use of the Madrean archipelago to extend their ranges northward are the elegant trogon and white-nosed coati.[13]
List by terrestrial realms
This section needs additional citations for verification. (October 2016) |
Afrotropical realm
- Cal Madow
- Cameroonian Highlands forests
- Ethiopian Highlands
- Highlands of southern Africa
- Green Mountain of Ascension Island
- Guinea Highlands
- Mount Cameroon and Bioko montane forests
- Mount Kilimanjaro
- Mount Gorongosa
- Rwenzori Mountains
Australasian realm
- Mount Wilhelm
- Mount Taranaki
- Waitakere Ranges
Indomalayan realm
- Mount Jerai
- Fansipan
- Jade Mountain
- Mount Kinabalu
- Nat Ma Taung
- Central Highlands (Vietnam)
- Titiwangsa Mountains
- Western Ghats
Nearctic realm
- Animas Mountains
- Black Range
- Capitan Mountains
- Chisos Mountains
- Colorado Plateau's San Francisco Peaks
- Chuska Mountains
- Great Basin montane forests
- Davis Mountains[14]
- Guadalupe Mountains
- San Jacinto Mountains
- Madrean sky islands
- Manzano Mountains
- Mogollon Mountains
- Oscura Mountains
- Olympic Mountains
- Peloncillo Mountains
- Quartz Mountains
- Sacramento Mountains
- San Augustin Mountains
- Sandia Mountains
- Spring Mountains
- Mount Taylor Volcano
- Wichita Mountains
Neotropical realm
- Baja California
- Sierra de la Laguna
- Sierra de Juarez
- Sierra San Pedro Mártir
- Cordillera of Central America
- Tepuis
- Serra do Mar
- Hispaniolan mountain ranges
- Sierra de Tamaulipas
- Venezuelan Coastal Range
Palearctic realm
See also
- Altitudinal zonation
- Life zone
- Holdridge life zones
- Inselberg or monadnock
- List of life zones by region
- Refugium (population biology)
- Table (landform)
- Tepui
References
- PMID 26338531.
- ^ Taylor, Edward Harrison. 1942. "Island" faunas on the Mexican Plateau. Proceedings of the 8th American Scientific Congress 3: 503-504.
- ^ Dodge, Natt (March 1943). "Monument in the Mountain". Arizona Highways. 19 (3). Phoenix, Arizona: Arizona Highway Department: 20–28.
- ^ Howell, John Thomas (May 1947). "Mono Mesa - Sierra Sky Island". Sierra Club Bulletin. 32 (5). San Francisco, California: Sierra Club: 15–18.
- Van Nostrand. pp. 114–126.
- ^ ISBN 978-0-684-82712-4.
- ISBN 978-0-374-10914-1.
- ^ Warshall, Peter (19 September 1994). "The Madrean Sky Island Archipelago: A Planetary Overview". Biodiversity and Management of the Madrean Archipelago. The Sky Islands of Southwestern United States and Northwestern Mexico. Fort Collins, Colorado: United States Forest Service.
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(help) - ^ McLaughlin, Steven P. (19 September 1994), An Overview of the Flora of the Sky Islands, Southeastern Arizona: Diversity, Affinities, and Insularity, Biodiversity and Management of the Madrean Archipelago. The Sky Islands of Southwestern United States and Northwestern Mexico, Fort Collins, Colorado: United States Forest Service
- ISBN 978-1-56098-845-8.
- ISBN 978-0-8061-1930-4.
- ^ "Mountain Quail fact sheet" (PDF). Nevada Department of Wildlife. Archived from the original (PDF) on 16 September 2012. Retrieved 8 May 2011.
- ISBN 978-0-88240-434-9.
- ^ "Davis Mountains Preserve | The Nature Conservancy". www.nature.org.