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| {{short description|Habitat type defined by the World Wide Fund for Nature}} | |||
| {{redirect|Xeric|the comic book grant foundation|Xeric Foundation}} | {{redirect|Xeric|the comic book grant foundation|Xeric Foundation}} | ||
| ], Algeria]] | |||
| ] | |||
| '''Deserts and xeric shrublands''' are a ] defined by the ].<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> ]s and xeric (] {{lang|grc|ξηρός}} {{translit|grc|xērós}} 'dry') ]s form the largest terrestrial biome, covering 19% of ]'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 ], are hot year-round, but others, such as East Asia's ], become quite cold during the winter.<ref name=wwf/> | |||
| ''']s and xeric shrublands''' is a ] characterized by, relating to, or requiring only a small amount of moisture.<ref> Merriam-Webster Dictionary definition of xeric</ref> | |||
| Temperature extremes are a characteristic of most deserts. High daytime temperatures give way to cold nights because there is no insulation provided by ] and cloud cover. The diversity of climatic conditions, though quite harsh, supports a rich array of habitats. Many of these habitats are ] 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/> | |||
| ==Definition and occurrence== | |||
| Deserts and xeric shrublands receive an annual average rainfall of ten inches or less, and have an ] or hyperarid climate, characterized by a strong moisture deficit, where annual potential loss of moisture from ] well exceeds the moisture received as rainfall. Deserts and xeric shrublands occur in ], ], and ] climate regions. | |||
| Desert ]s tend to be sandy or rocky, and low in organic materials. ] or ] soils are common. | |||
| ]s and ]s in deserts and xeric shrublands are adapted to low moisture conditions. Hyperarid regions are mostly devoid of vegetation and animal life, and include rocky deserts and ]s. Vegetation in arid climate regions can include sparse ]s, ]s, and ]s. Plants adapted to arid climates are called ]s, and include ]s, ]s, ], and ]s. Animals, including ]s, ]s, ]s, ]s and ]s, are frequently ] to avoid moisture loss. | |||
| ] have adapted to xeric microclimates within volcanic craters, trapping and channeling dew and protecting leaves with reflective hairs.]] | |||
| == |
== Degradation == | ||
| ⚫ | The conversion of productive ] to desert conditions |
||
| ===Desertification=== | |||
| ⚫ | ==See also== | ||
| {{Main article|Desertification}} | |||
| *] | |||
| ] 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 ] to desert conditions, known as ], can occur from a variety of causes. One is human intervention, including intensive agricultural tillage or ]<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 ] or the ] (which drives ] and ]s) also affect the pattern of deserts on Earth. | ||
| *] | |||
| ⚫ | * |
||
| ⚫ | * |
||
| ⚫ | * |
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| *] | |||
| === Woody plant encroachment === | |||
| ⚫ | |||
| {{Main article|Woody plant encroachment}} | |||
| {{Afrotropic deserts and xeric shrublands}} | |||
| {{Australasia deserts and xeric shrublands}} | |||
| {{Indomalaya deserts and xeric shrublands}} | |||
| {{Nearctic deserts and xeric shrublands}} | |||
| {{Neotropic deserts and xeric shrublands}} | |||
| {{Paleartic deserts and xeric shrublands}} | |||
| Xeric shrublands can experience woody plant encroachment, which is the thickening of bushes and shrubs at the expense of grasses.<ref>{{Cite journal|last1=Eldridge|first1=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|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 can also be a consequence of ]. As a result, the shrublands' core ] are affected, including its biodiversity, productivity, and groundwater recharge.<ref>{{Citation|last1=Archer|first1=Steven R.|title=Woody Plant Encroachment: Causes and Consequences|date=2017|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|last2=Andersen|first2=Erik M.|last3=Predick|first3=Katharine I.|last4=Schwinning|first4=Susanne|last5=Steidl|first5=Robert J.|last6=Woods|first6=Steven R.|series=Springer Series on Environmental Management |s2cid=133015720 |doi-access=free}}</ref> Woody plant encroachment can be an expression of land degradation.<ref>{{Cite journal|last1=Schlesinger|first1=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|pmid=17800060 |bibcode=1990Sci...247.1043S |s2cid=33033125 |issn=0036-8075}}</ref> | |||
| ⚫ | {{Biomes}} | ||
| ==Ecoregions== | |||
| {{see also|List of desert and xeric shrubland ecoregions}} | |||
| The World Wide Fund for Nature highlights a number of desert ]s that have a high degree of ] and ]:<ref name=wwf/> | |||
| * The ] 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 ] and ] are the richest deserts in the ].<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|pmid=34261239 }}</ref> | |||
| * The ] of Australia are a regional center for endemism.<ref name=wwf/> | |||
| * The ] and ] of Mexico are unusual desert communities dominated by giant ].<ref name=wwf/> | |||
| * ] | |||
| ⚫ | * ] | ||
| ⚫ | ==See also== | ||
| {{div col}} | |||
| * {{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}} | ||
| * ] — gardening or landscaping in xeric environments | |||
| * ]s — animals adapted to xeric environments | |||
| * ]s — plants adapted to xeric environments | |||
| {{div col end}} | |||
| ==References== | ==References== | ||
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| ==External links== | ==External links== | ||
| {{commons}} | |||
| * | |||
| * | * | ||
| * Online |
* Online community focused on the study of xeric plant species | ||
| * | |||
| ⚫ | {{Palearctic desert and xeric shrubland ecoregions}} | ||
| ⚫ | {{Biomes}} | ||
| {{Biodiversity of South Africa|ecoreg}} | |||
| ] | ] | ||
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Latest revision as of 21:32, 15 November 2024
Habitat type defined by the World Wide Fund for Nature "Xeric" redirects here. For the comic book grant foundation, see Xeric Foundation.
Deserts and xeric shrublands are a biome defined by the World Wide Fund for Nature. Deserts and xeric (Ancient Greek ξηρός xērós 'dry') shrublands form the largest terrestrial biome, covering 19% of Earth's land surface area. Ecoregions in this habitat type vary greatly in the amount of annual rainfall they receive, usually less than 250 millimetres (10 in) 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, are hot year-round, but others, such as East Asia's Gobi Desert, become quite cold during the winter.
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. 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.
Degradation
Desertification
Main article: Desertification
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 in areas that cannot support such exploitation. Climatic shifts such as global warming or the Milankovitch cycle (which drives glacials and interglacials) also affect the pattern of deserts on Earth.
Woody plant encroachment
Main article: Woody plant encroachmentXeric shrublands can experience woody plant encroachment, which is the thickening of bushes and shrubs at the expense of grasses. This process is often caused by unsustainable land management practices, such as overgrazing and fire suppression, but can also be a consequence of climate change. As a result, the shrublands' core ecosystem services are affected, including its biodiversity, productivity, and groundwater recharge. Woody plant encroachment can be an expression of land degradation.
Ecoregions
See also: List of desert and xeric shrubland ecoregionsThe World Wide Fund for Nature highlights a number of desert ecoregions that have a high degree of biodiversity and endemism:
- The Nama Karoo of Namibia has the world's richest desert fauna.
- The Chihuahuan desert and Central Mexican matorral are the richest deserts in the Neotropics.
- The Carnarvon xeric shrublands of Australia are a regional center for endemism.
- The Sonoran and Baja deserts of Mexico are unusual desert communities dominated by giant columnar cacti.
- Madagascar spiny forests
- Atacama Desert
See also
- Hydric soil – soil typePages displaying wikidata descriptions as a fallback
- Mesic – Habitat with a moderate supply of moisture
- Rain shadow – Leeward side of a mountain range
- Sagebrush steppe – Grassland ecosystem
- Shrub-steppe – Arid grasslandPages displaying short descriptions of redirect targets
- Temperate grasslands, savannas, and shrublands – Terrestrial biome
- Xeriscaping — gardening or landscaping in xeric environments
- Xerocoles — animals adapted to xeric environments
- Xerophytes — plants adapted to xeric environments
References
- ^
This article incorporates text available under the CC BY-SA 3.0 license. World Wide Fund for Nature. "Deserts and Xeric Shrubland Ecoregions". Archived from the original on 2012-04-25. Retrieved 2019-05-29.
- Lockwood, M. Managing Protected Areas: A Global Guide. p. 199.
- "Nama Karoo". WWF. Retrieved 2018-12-19.
- Hogan, C. Michael (2009). "Overgrazing". In Draggan, Sidney; Cleveland, Cutler J. (eds.). Encyclopedia of Earth. Washington, D.C.: National Council for Science and the Environment.
- Eldridge, David J.; Bowker, Matthew A.; Maestre, Fernando T.; Roger, Erin; Reynolds, James F.; Whitford, Walter G. (July 2011). "Impacts of shrub encroachment on ecosystem structure and functioning: towards a global synthesis: Synthesizing shrub encroachment effects". Ecology Letters. 14 (7): 709–722. doi:10.1111/j.1461-0248.2011.01630.x. PMC 3563963. PMID 21592276.
- Archer, Steven R.; Andersen, Erik M.; Predick, Katharine I.; Schwinning, Susanne; Steidl, Robert J.; Woods, Steven R. (2017), Briske, David D. (ed.), "Woody Plant Encroachment: Causes and Consequences", Rangeland Systems, Springer Series on Environmental Management, Cham: Springer International Publishing, pp. 25–84, doi:10.1007/978-3-319-46709-2_2, ISBN 978-3-319-46707-8, S2CID 133015720
- Schlesinger, William H.; Reynolds, James F.; Cunningham, Gary L.; Huenneke, Laura F.; Jarrell, Wesley M.; Virginia, Ross A.; Whitford, Walter G. (1990-03-02). "Biological Feedbacks in Global Desertification". Science. 247 (4946): 1043–1048. Bibcode:1990Sci...247.1043S. doi:10.1126/science.247.4946.1043. ISSN 0036-8075. PMID 17800060. S2CID 33033125.
- Cowling, RM; Hilton-Taylor, C (1994). "Patterns of plant diversity and endemism in southern Africa: An overview". In Huntley, BJ (ed.). Botanical diversity in southern Africa. Pretoria, South Africa: National Botanical Institute. pp. 31–52.
- Hernandez, HM; Barcenas, RT (1995). "Endangered cacti in the Chihuahuan Desert: I. Distribution patterns". Conservation Biology. 9 (5): 1176–1188. doi:10.1046/j.1523-1739.1995.9051169.x-i1. PMID 34261239.
External links
- Index to Deserts & Xeric Shrublands at bioimages.vanderbilt.edu
- Xeric World Online community focused on the study of xeric plant species
- Desert Plants: List, Names and Adaptations
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