Deserts and xeric shrublands

2022-03-27T05:45:05Z

2601:243:1980:2810:5DBD:83CC:3E08:5BA2: robot: Creating new article from Special:WantedPages

{{short description|Habitat type defined by the World Wide Fund for Nature}}
{{redirect|Xeric|the comic book grant foundation|Xeric Foundation}}
[[File:Biome_map_13.svg|thumb|right|250px|Extent of deserts and xeric shrublands]]
'''Deserts and xeric shrublands''' are a [[biome]] defined by the [[World Wide Fund for Nature]].<ref name=wwf>{{CC-notice|bysa3}} {{cite web|archive-url=https://web.archive.org/web/20120425205057/http://wwf.panda.org/about_our_earth/ecoregions/about/habitat_types/selecting_terrestrial_ecoregions/habitat13.cfm|archive-date=2012-04-25|url=http://wwf.panda.org:80/about_our_earth/ecoregions/about/habitat_types/selecting_terrestrial_ecoregions/habitat13.cfm|title=Deserts and Xeric Shrubland Ecoregions|author=World Wide Fund for Nature|access-date=2019-05-29|url-status=live}}</ref> Deserts and xeric (ancient Greek xērós, “dry") shrublands form the largest terrestrial biome, covering 19% of [[Earth]]'s land surface area.<ref>{{cite book|last=Lockwood|first=M.|title=Managing Protected Areas: A Global Guide|page=199}}</ref> Ecoregions in this habitat type vary greatly in the amount of annual rainfall they receive, usually less than {{convert|10|in|mm|order=flip}} annually except in the margins. Generally evaporation exceeds rainfall in these ecoregions. Temperature variability is also diverse in these lands. Many deserts, such as the [[Sahara desert|Sahara]], are hot year-round, but others, such as East Asia's [[Gobi desert|Gobi]], become quite cold in winter.<ref name=wwf/>

Temperature extremes are a characteristic of most deserts. High daytime temperatures give way to cold nights because there is no insulation provided by [[humidity]] and cloud cover. The diversity of climatic conditions, though quite harsh, supports a rich array of habitats. Many of these habitats are [[ephemeral]] in nature, reflecting the paucity and seasonality of available water.<ref name=wwf/> Woody-stemmed shrubs and plants characterize vegetation in these regions. Above all, these plants have evolved to minimize water loss. Animal biodiversity is equally well adapted and quite diverse.<ref name=wwf/>

== Degradation ==

===Desertification===
{{Main article|Desertification}}
[[File:Sengi-landscape Nama Karoo.tif|thumb|right|The [[Nama Karoo]] in South Africa is a xeric shrubland that receives between {{convert|100|and|500|mm|in|0}} of rain a year.<ref>{{cite web|url=https://www.worldwildlife.org/ecoregions/at1314|title=Nama Karoo|publisher=WWF|access-date=2018-12-19}}</ref>]]
The conversion of productive [[drylands]] to desert conditions, known as [[desertification]], can occur from a variety of causes. One is human intervention, including intensive agricultural tillage or [[overgrazing]]<ref>{{cite encyclopedia|first=C. Michael|last=Hogan|year=2009|url=https://editors.eol.org/eoearth/wiki/Overgrazing|title=Overgrazing|encyclopedia=Encyclopedia of Earth|editor-first1=Sidney|editor-last1=Draggan|editor-first2=Cutler J.|editor-last2=Cleveland|publisher=National council for Science and the Environment|location=Washington, D.C.}}</ref> in areas that cannot support such exploitation. Climatic shifts such as [[global warming]] or the [[Milankovitch cycle]] (which drives [[Glacial period|glacials]] and [[interglacial]]s) also affect the pattern of deserts on Earth.

=== Woody plant encroachment ===
{{Main article|Woody plant encroachment}}

Xeric shrublands can experience woody plant encroachment, which is the thickening of bushes and shrubs at the expense of grasses.<ref>{{Cite journal|last=Eldridge|first=David J.|last2=Bowker|first2=Matthew A.|last3=Maestre|first3=Fernando T.|last4=Roger|first4=Erin|last5=Reynolds|first5=James F.|last6=Whitford|first6=Walter G.|date=July 2011|title=Impacts of shrub encroachment on ecosystem structure and functioning: towards a global synthesis: Synthesizing shrub encroachment effects|url=https://onlinelibrary.wiley.com/doi/10.1111/j.1461-0248.2011.01630.x|journal=Ecology Letters|language=en|volume=14|issue=7|pages=709–722|doi=10.1111/j.1461-0248.2011.01630.x|pmc=3563963|pmid=21592276}}</ref> This process is often caused by unsustainable land management practices, such as overgrazing and fire suppression, but also a consequence of climate change. As a result, core [[ecosystem services]] of the shrublands are affected, including its biodiversity, productivity and groundwater recharge.<ref>{{Citation|last=Archer|first=Steven R.|title=Woody Plant Encroachment: Causes and Consequences|date=2017|url=http://link.springer.com/10.1007/978-3-319-46709-2_2|work=Rangeland Systems|pages=25–84|editor-last=Briske|editor-first=David D.|place=Cham|publisher=Springer International Publishing|language=en|doi=10.1007/978-3-319-46709-2_2|isbn=978-3-319-46707-8|access-date=2021-12-10|last2=Andersen|first2=Erik M.|last3=Predick|first3=Katharine I.|last4=Schwinning|first4=Susanne|last5=Steidl|first5=Robert J.|last6=Woods|first6=Steven R.}}</ref> Woody plant encroachment can be an expression of land degradation.<ref>{{Cite journal|last=Schlesinger|first=William H.|last2=Reynolds|first2=James F.|last3=Cunningham|first3=Gary L.|last4=Huenneke|first4=Laura F.|last5=Jarrell|first5=Wesley M.|last6=Virginia|first6=Ross A.|last7=Whitford|first7=Walter G.|date=1990-03-02|title=Biological Feedbacks in Global Desertification|url=https://www.science.org/doi/10.1126/science.247.4946.1043|journal=Science|language=en|volume=247|issue=4946|pages=1043–1048|doi=10.1126/science.247.4946.1043|issn=0036-8075}}</ref>
==Ecoregions==
{{see also|List of desert and xeric shrubland ecoregions}}

The World Wide Fund for Nature highlights a number of desert [[ecoregion]]s that have a high degree of [[biodiversity]] and [[endemism]]:<ref name=wwf/>
* The [[Nama Karoo]] of Namibia has the world's richest desert fauna.<ref>{{cite book|last1=Cowling|first1=RM|first2=C|last2=Hilton-Taylor|year=1994|chapter=Patterns of plant diversity and endemism in southern Africa: An overview|pages=31–52|editor-first=BJ|editor-last=Huntley|title=Botanical diversity in southern Africa|publisher=National Botanical Institute|location=Pretoria, South Africa}}</ref>
* The [[Chihuahuan desert]] and [[Central Mexican matorral]] are the richest deserts in the [[Neotropics]].<ref>{{cite journal|last1=Hernandez|first1=HM|first2=RT|last2= Barcenas|year=1995|title=Endangered cacti in the Chihuahuan Desert: I. Distribution patterns|journal=Conservation Biology|volume=9|issue=5|pages=1176–1188|doi=10.1046/j.1523-1739.1995.9051169.x-i1}}</ref>
* The [[Carnarvon xeric shrublands]] of Australia are a regional center for endemism.<ref name=wwf/>
* The [[Sonoran Desert|Sonoran]] and [[Baja California Desert|Baja deserts]] of Mexico are unusual desert communities dominated by giant [[columnar cactus|columnar cacti]].<ref name=wwf/>
* [[Madagascar spiny forests]]
* [[Atacama Desert]]

==See also==
{{div col}}
* {{annotated link|Desert}}
* {{annotated link|Hydric soil}}
* {{annotated link|Mesic habitat|Mesic}}
* {{annotated link|Rain shadow}}
* {{annotated link|Sagebrush steppe}}
* {{annotated link|Shrub-steppe}}
* {{annotated link|Temperate grasslands, savannas, and shrublands}}
* [[Xeriscaping]] — gardening or landscaping in xeric environments
* [[Xerocole]]s — animals adapted to xeric environments
* [[Xerophyte]]s — plants adapted to xeric environments
{{div col end}}

==References==
{{Reflist}}

==External links==
* [https://web.archive.org/web/20120905010259/http://www.cas.vanderbilt.edu/bioimages/ecoframe-list.htm Index to Deserts & Xeric Shrublands at bioimages.vanderbilt.edu]
* [https://web.archive.org/web/20090129105807/http://www.xericworld.com/forums/ Xeric World] Online community focused on the study of xeric plant species

{{Paleartic deserts and xeric shrublands}}
{{Biomes}}
{{Biodiversity of South Africa|ecoreg}}

[[Category:Deserts and xeric shrublands| ]]
[[Category:Terrestrial biomes]]
[[Category:Flora of the California desert regions]]
[[Category:North American desert flora| ]]

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Deserts and xeric shrublands