WikiWorks at 13:09, 2 December 2007

2007-12-02T13:09:39Z

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'''Endemism''' is the [[ecological]] state of being unique to a place. Endemic species are not naturally found elsewhere. The place must be a discrete geographical unit, such as an island, [[Habitat (ecology)|habitat]] type, or other defined area or zone. For example, the orange-breasted [[sunbird]] (''Anthobaphes violacea'') is endemic to [[Fynbos]], meaning it is exclusively found in the Fynbos vegetation type of southwestern [[South Africa]].

An opposite notion is [[cosmopolitan distribution]].

Endemic types or species are especially likely to develop on islands due to their geographical isolation. This includes remote island groups, such as [[Endemism in the Hawaiian Islands|Hawaii]], the [[Galápagos Islands]] and [[Socotra]]. Endemism can also occur in biologically isolated areas such as the highlands of [[Ethiopia]], or large bodies of water like [[Lake Baikal]].

Endemics can easily become [[endangered]] or [[extinct species|extinct]] due to their restricted habitat and vulnerability to the actions of man, including the [[introduced species|introduction]] of new organisms. There were millions of both petrels and "cedars" (actually junipers) in [[Bermuda]] when it was settled at the start of the 17th century. By the end of the century, the petrels were thought to be extinct, and cedars were driven nearly to extinction. This was caused by centuries of shipbuilding as well as the introduction of a parasite. Both petrels and cedars are very rare today, as are other species endemic or native to Bermuda.

Endemic organisms are not the same as [[indigenous (ecology)|indigenous organisms]] — a species that is indigenous to somewhere may be native to other locations as well. An [[introduced species]], also known as a naturalized or exotic species, is an organism that is not indigenous to a given place or area.

==Ecoregions with high endemism==
According to the [[World Wildlife Fund]], the following [[ecoregions]] have the highest percentage of endemic plants:

* [[Fynbos]] ([[South Africa]])
* [[Hawaii dry forests]] ([[United States]])
* [[Hawaii tropical moist forests]] ([[United States]])
* [[Kwongan heathlands]] ([[Australia]])
* [[Madagascar dry deciduous forests]] ([[Madagascar]])
* [[Madagascar lowland forests]] ([[Madagascar]])
* [[New Caledonia dry forests]] ([[New Caledonia]])
* [[New Caledonia rain forests]] ([[New Caledonia]])
* [[Sierra Madre de Oaxaca pine-oak forests|Sierra Madre de Oaxaca]] and [[Sierra Madre del Sur pine-oak forests]] ([[Mexico]], [[Guatemala]])

==Threats to highly endemistic regions==

Some of the principal threats to these special ecosystems are:

* [[Global warming]]
* Large scale [[logging]] operations
* [[Slash-and-burn]] techniques sometimes a part of [[shifting cultivation]]

The above factors are secondary results of world [[overpopulation]].

== See also ==
* [[Floristic province]]

[[Category:Ecology]]
[[Category:Biodiversity]]
[[Category:Biogeography]]

Endemic (ecology) - Revision history

WikiWorks at 13:09, 2 December 2007