Middle East steppe

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Jordan (Photograph by Marco Pagliani/WWF MedPO)

Introduction

The most outstanding geographic features of this ecoregion are the stretches of the Tigris and Euphrates Rivers that pass through on their voyage from Turkey to the Persian Gulf. These rivers support wildlife, plants, agriculture and other human activities as they have for millenia in this area of the Fertile Crescent. Sage brush and other shrub and grass vegetation are found here, as well as riverine woodlands and wetland areas. In spite of many threats and an overall species decline, a remarkable diversity of bird species still depends on the region's water bodies and arid habitats. Globally vulnerable species such as the Arabian goitered gazelle, marbled teal and lesser kestrel, are still found here.

Location and General Description

caption WWF

This region consists mainly of open shrub steppe in Syria and northern Iraq. It arcs up from western Jordan and southwestern Syria through much of central Syria and into northern Iraq. Here, it crosses the upper reaches of the Euphrates and Tigris rivers and extends east and southwards along the foothills of the Zagros Mountains. Geological features are varied and include calcareous Mesozoic and Tertiary rocks and alluvial-colluvial soils in the Tigris-Euphrates valley. Boulder fields of black basalt characterize the southeastern portion of this region.

A marked continental climate prevails here, with high summer temperatures, relatively cold winters, and many nights of frost. The average annual rainfall is less than 250 millimeters (mm), and climatic conditions become progressively more arid to the east and south, where the shrub steppe blends into the Syrian desert. Average temperatures can range from 7 degrees Celcius (C) in January to 27 degrees C in July. In spring and autumn, the hot and dusty "khamsin" wind, blowing from the east and southeast, may cause temperatures to rise as high as 43-49 degrees C.

Vegetation is reflective of the Mesopotamian province of the Irano-Turanian region. Herbaceous and dwarf shrub sage brush (Artemisia herba-alba) communities tend to dominate in deeper, non-saline soils and often occur in association with grasses (Poa bulbosa) where disturbed by grazing. Hammada scoparia characterizes stony soils. Islands in the Euphrates River continue to support remnants of the native riverine woodland. Tamarix spp. and Populus euphratica are encountered near water and Phragmites spp. reeds grow in wetland areas. Scattered permanent and seasonal lakes and marshes, both freshwater and saline, are also found.

Biodiversity Features

caption Jordan (Photograph by Marco Pagliani/ WWF MedPO)

Large mammals can be found in areas where human settlements are less dense. Predators such as wolves (Canis lupus), Ruppell’s sand fox (Canis ruppelii), caracals (Felis caracal), jungle cats (Felis chaus), and wildcats (Felis silvestris) are still occasionally encountered. Arabian goitered gazelle (Gazella subgutturosa ssp. marica), classified as vulnerable by the IUCN, and badgers (Meles meles) can be found in more vegetated areas, and wild boar (Sus scrofa) can be found in reed thickets and semi-desert terrain.

 

The combination of arid steppe and riverine habitat allow this area to support a tremendous diversity of bird species that depend on both arid areas and wetlands. The houbara bustard (Chlamydotis undulata), great bustard (Otis tarda), and little bustard (Tetrax tetrax), are found in semi-desert areas; Otis tarda is listed as vulnerable by the IUCN Red List and the other two are included in the Lower Risk category. The lesser kestrel (Falco naumanni), also listed as vulnerable by the IUCN, may breed locally in steppe areas. The regionally threatened Eurasian griffon vulture (Gyps fulvus) and lanner falcon (Falco biarmicus) also occur. The Euphrates Valley is a major migration route for waterbirds, its oxbow lakes and riverine marshes providing a narrow corridor between the important wetlands of southern and central Turkey and the vast wetlands of Mesopotamia in Iraq. Greater flamingos (Phoenicopterus ruber) depend on its seasonal salt lakes, and the pygmy cormorant (Phalacrocorax pygmeus) and marbled teal (Marmaronetta angustirostris) are known to breed here; Marmaronetta angustirostris is considered vulnerable by the IUCN. The valley is also a very important migration route for terrestrial birds such as the turtle dove (Streptopelia turtur), which is said to gather in the hundreds of thousands on islands in the river in spring and autumn. The pin-tailed sandgrouse (Pterocles alchata) is common on the adjacent plains and visits the river in large numbers to drink.

Current Status

Much of the original vegetation in this region can now only be found in small pockets. Evidence suggests that a kind of steppe-forest with scattered trees and more extensive grasses may have once occupied much of this area, but centuries of grazing and fuel-wood collection have changed its ecological character. Large ungulates such as Gazella subgutturosa ssp. marica are rare due to hunting pressures and competition from domestic animals. Man-made reservoirs, while altering natural hydrological regimes, nevertheless serve as very important staging and wintering areas for migratory waterfowl.

Types and Severity of Threats

Thousands of years of human habitation have taken a severe toll on this region's flora and fauna. Agriculture has historically been concentrated in the ancient 'Fertile Crescent' which overlaps with much of this area, and drainage of wetlands and conversion of steppe to rainfed and irrigated farmland are ongoing problems. Many naturally occurring lakes are now much reduced in size and have been partly or wholly converted into fishponds. Export crops such as cotton, wheat, barley, rice, olives, millet, sugarbeet and tobacco are grown here, and the use of agrochemicals contributes to water pollution. Dam projects and irrigation schemes, most notably the huge Asad Dam on the Euphrates River, have permitted a major expansion in the area of arable land, and additional dams are planned or under way.

Phragmites spp. reedbeds are burned to encourage regrowth for livestock grazing, and riverine woodland is heavily exploited for firewood. Hunting of waterfowl and gamebirds such as bustards (Otididae spp.) is intense. While raptor populations are generally healthy, they are heavily persecuted for the taxidermy trade.

Extensive overgrazing of arid steppe regions by domestic livestock such as sheep, goats, donkeys and camels has contributed to the alteration and degradation of vegetation communities. Even the remotest areas are accessible to livestock when wells are constructed or water is transported in from other locations.

Phosphate mining and manufacturing also threatens fragile arid environments.

Justification of Ecoregion Delineation

This ecoregion was defined using a combination of two bioregional systems. The western and southern portions of the ecoregion are equivalent to the North Africa & Middle East non-tree steppes described by Guidotti. The eastern portion is based on the Mesopotamian steppes of Artmisietea herbae-albae mesopotamica as described by Zohary.

Additional information on this ecoregion

Further Reading

  • IUCN, 2001. IUCN 2000 red list of threatened species. IUCN, Gland, Switzerland. ISBN: 2831705657
  • Mares, M., editor. 1999. Encyclopedia of Deserts. University of Oklahoma Press, Norman, OK.
  • Orshan, G. 1986. The Deserts of the Middle East. Pages 1-28 in M. Evenari, I. Noy-Meir, and D. Goodall, editors. Ecosystems of the world 12B: hot deserts and arid shrublands. Elsevier Scientific Publishing Company, Amsterdam, The Netherlands. ISBN: 0806131462
  • Scott, D.A., editor. 1995. A directory of wetlands in the Middle East. IUCN, Gland, Switzerland and IWRB, Slimbridge, United Kingdom. ISBN: 2831702704
  • Zohary, M. 1973. Geobotanical Foundations of the Middle East, volumes 1, 2. Gustav Fischer Verlag, Stuttgart, Germany. ASIN B0006CB7Z4.

 

 

Disclaimer: This article is taken wholly from, or contains information that was originally published by, the World Wildlife Fund. Topic editors and authors for the Encyclopedia of Earth may have edited its content or added new information. The use of information from the World Wildlife Fund should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content.

 

 

 

 

Glossary

Citation

Fund, W. (2014). Middle East steppe. Retrieved from http://www.eoearth.org/view/article/154605

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