Deserts and xeric shrublands
Deserts and xeric shrublands also called xerófila are a biome characterized by, relating to, or requiring only a small amount of moisture, usually defined as less than 250 mm of annual precipitation. It is the largest terrestrial biome, covering 19% of the earth's land surface area. Evaporation usually exceeds rainfall in these regions. They may be further characterized as hiperxerófila (very dry) and hypoxerófila (less dry).
Character of the Biome
Deserts and xeric shrublands may have extraordinarily rich floras with very high alpha and beta diversity; reptile faunas may also be very diverse; local endemism may be quite pronounced in some regions.
Many species track seasonally variable and patchy resources and require large natural landscapes to persist; water sources and riparian habitats are critical for the persistence of many species.
Because biomass productivity is low, the litter layer is almost nonexistent and organic content of surface soil layers is very low. Finally, evaporation tends to concentrate salts at the soil surface.
Sensitivity to Disturbance
Highly sensitive to grazing, soil disturbance, burning, plowing, and other cover alteration; restoration potential can be very low and regeneration very slow; exotic species may be a serious problem.
The conversion of productive drylands to desert conditions is known as desertification, and can occur from a variety of causes. One factor is human intervention in imposing intensive agricultural tillage or overgrazing in areas which 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.
Desert and xeric shrublands ecoregions
Australasia Deserts and xeric shrublands
|Carnarvon xeric shrublands||Australia|
|Central Ranges xeric scrub||Australia|
|Great Sandy-Tanami Desert||Australia|
|Great Victoria Desert||Australia|
|Nullarbor Plain xeric shrublands||Australia|
|Tirari-Sturt's Stony Desert||Australia|
|Western Australian mulga shrublands||Australia|
Indomalaya Deserts and xeric shrublands
|Deccan thorn scrub forests||India, Sri Lanka|
|Indus Valley desert||India, Pakistan|
|Northwestern thorn scrub forests||India, Pakistan|
|Thar desert||India, Pakistan|
Nearctic Deserts and xeric shrublands
|Baja California desert||Mexico|
|Central Mexican matorral||Mexico|
|Chihuahuan desert||Mexico, United States|
|Colorado Plateau shrublands||United States|
|Great Basin shrub steppe||United States|
|Gulf of California xeric scrub||Mexico|
|Meseta Central matorral||Mexico|
|Mojave desert||United States|
|Okanagan (South) shrub steppe||Canada|
|Snake-Columbia shrub steppe||United States|
|Sonoran desert||Mexico, United States|
|Tamaulipan mezquital||Mexico, United States|
|Wyoming Basin shrub steppe||United States|
- Xeriscaping- gardening or landscaping in xeric environments
- Xerophytes- plants adapted to xeric environments
- Temperate grasslands, savannas, and shrublands
- Sagebrush steppe
- Merriam-Webster.com Merriam-Webster Dictionary definition of xeric
- Lockwood, M. Managing Protected Areas: A Global Guide. p. 199.
- C.Michael Hogan. 2009. Overgrazing. Encyclopedia of Earth. Sidney Draggan, topic ed.; Cutler J. Cleveland, ed., National council for Science and the Environment, Washington DC
- Deserts and xeric shrublands (World Wildlife Fund)[dead link]
- Index to Deserts & Xeric Shrublands at bioimages.vanderbilt.edu
- Xeric World Online Community focused on the study of Xeric Plant Species.