Alai-Western Tian Shan steppe

Content Cover Image

Aktash, Karzhantau Gorge, Uzbekistan (Photograph by A. Kliouchnik)

Introduction

The climatic conditions of this ecoregion allow for unique types of ephemeroidal herbaceous vegetation and for the conservation of relic species and plant communities on foothill plains in Western Tien Shan and Alai, and in arid mountain areas. Flora of the region is highly diverse (more than 2000 species) and includes many endemics. This region is characterized by a rich diversity of flora and the high level of endemism. The fauna or the region is also very diverse with a number of endemic and rare mammals, birds, and reptiles and amphibians. Extensive agricultural development and population-related pressures continue to have a significant negative influence on biodiversity and biological integrity of the region.

Location and General Description

caption WWF

This ecoregion includes the vast foothill plains in western Tien Shan and Alai as well as two mountain massives – Kara Tau, Nura Tau and the Fergana Valley. Most of the area is covered by raised foothill plains and disjunct loess foothills. Arid and sub-arid mountains are situated in the north (Kara Tau) and central part (Nura Tau) of the ecoregion. The average annual precipitation is 300-600 millimeters (mm) with the maximum falling in August. The average annual temperature is 11o - 13o Celcius (C). The temperature range in January is -2 to 12oC and in July 22 to 28oC. Both the precipitation and temperature variations correspond to the area’s altitude. Slates, chalkstones, limestones, granites and porphyries form these mountains.

The flora is varied, very rich (more than 2000 species) and includes many endemics. For example, the flora of Kara Tau includes 1700 species, of which 153 are endemics. Nura Tau flora includes 1200 species, 377 of which aren’t found in Kara Tau. The lower areas of the foothill plains are occupied by a low herbaceous and herbaceous-ephemeroid vegetation called savannoides. Ephemeroids such as Poa bulbosa, Carex pachystilis and species such as Artemisia cina, A. serotina, Phlomis salicifolia, and Cousinia syrdariensis are characteristic. As the hypsometric level increases, high ephemeroid grasses such as Elytrigia trichophora, Hordeum bulbosum begin to dominate the plant communities. In low areas of the western Tien Shan region, the colorful tall herbs Ferula karatavica, Alcea nudiflora, and Eremurus regelii are important. The tall umbellates - Prangos pubularia, Ferula tenuisecta appear higher in loess foothills. In the Alai region, Phlomis phapsoides, Eremostachys eriocalyx, and Psorolea drupacea grow among tall herbs.

The vegetation of Kara Tau is represented by communities on stone soils that include such endemics as Lepidolopha karatavica, Rhaphidophyton regelii, Scorzonera tau-sagyz and pulvinates such as Cousinia mindshelkensis. The steppes are characterized by northern-steppe elements (Festuca valesiaca, Stipa kirghisorum) and the presence of local endemics (Stipa karatavica). The brushwoods, with participation of different species Cerasus, Rhamnus, Spiraea, and Cotoneaster are varied. Pears, almonds, hawthorns, pistachios (e.g., Pyrus regelii, Crataegus pontica, Amygdalus petunnikovii, and Pistacia vera), "iron tree" (Celtis caucasica) grows in gorges.

Low and tall herb savannoides vegetation is widely represented in the Nura Tau mountains. The petrophytic brushwoods with almonds (e.g., Amygdalus spinosissima), maple woods with Acer pubescens, pistachio communities with Pistacea vera and fragments of open woodlands with Juniperus seravshanica are typical here.

Biodiversity Features

The diversity of vertebrates in the low and middle mountain turfgrass steppes includes representative species from steppe, desert, and mountain areas. Along with fox (Vulpes vulpes) and corsac (Vulpes corsac), one can find long-eared hedgehog (Hemiechinus auritus), tolai hare (Lepus tolai), jackal (Canis aureus), badger (Meles meles), many rodent species such as ground squirrels (Spermophilus spp.), gerbils (Meriones spp.), and jerboas (Allactaga spp.). Also common are the yellow ground squirrel (Spermophilus fulvus), numerous species of voles (Microtus spp.) and bats (Chiroptera spp.). Among birds, the typical representatives include larks (Alaudidae), pipits (Anthus; including the field pipit, Anthus campestris), wheatears (Oenanthe), buntings (Emberiza), Eastern stock dove (Columba eversmanni), turtle dove (Streptopelia turtur), roller (Coracias garrulus), hoopoe (Upupa epops), corn bunting (Miliaria calandra), black-foreheaded shrike (Lanius minor), golden and green bee-eaters (Merops apiaster, M. superciliosus), and sandgrouse (Pterocles orientalis). Birds of prey include kestrel (Falco tinnunculus), Montagu's harrier (Circus pygargus), and steppe eagle (Aquila rapax). The bustard (Tetrax tetrax) and stone curlew (Burhinus oedicnemus) are still found in some areas. The ibisbill (Ibidorhyncha struthersii) is considered very rare.

caption Tian Shan mountains, Turkmenistan (Photograph by Olga Pereladova)

The complex of desert reptiles is represented by the Central Asian tortoise (Agrionemys horsfieldi), lizards such as agamids (Trapelas, Phrynocephalus), gekkos (Alsophylax, Cyrtopodion, Teratoscincus), sand lizards (Eremias), skinks (Ablepharus, Eumeces, Mabuya), and common snakes such as sand boas (Eryx miliaris), colubrids (Coluber, Spalerosophis, Elaphe), sand snakes (Psammophis), echis (Echis multisquamatus) and gyurza (Vipera lebetina).

The ecosystems of the steppe and semi-desert foothills and the low mountain belt include such rare ungulates as goitered gazelle (Gazella subgutturosa), Kizylkum wild sheep (O. a. severtzovi) which inhabits Nuratau and Aktau, and Karatau wild sheep (O. a. nigrimontana) in the Karatau range. Also found is a rare bat, (Tadarida teniotis) which inhabits caves and crevices. Among the rare carnivores are hyena (Hyaena hyaena), marbled polecat (Vormela peregusna), and Pallas’ cat (Otocolobus manul). Rare birds include saker falcon (Falco cherrug), Barbary falcon (Falco pelegrinoides), and short-toed eagle (Circaetus gallicus). Notable reptiles include the chalcid skink (Chalcides ocellatus), gray monitor (Varanus griseus), snakes (Oligodon taeniolatus, Lycodon striatus, Coluber spinalis), and the Central Asian cobra (Naja oxiana).

The neighboring upper slopes of the West Tian Shan mountains are inhabited by roe deer (Cervidae Capreolus), and wild boar (Sus scrofa), and brown bear (Ursus arctos isabellinus) can sometimes be encountered.

Current Status

There are numerous protected areas in Western Tian Shan and one in Nuratau. The three zapovedniks of the West Tian Shan have all been nominated as World Heritage sites. The unique vegetation cover of the Kara Tau mountains requires full protection and classification as a reserve as soon as possible.

Fergana valley is an area with extensive agricultural utilization and one of the highest population densities in Central Asia. Development of ecologically-friendly agriculture as an alternative to cotton mono-culture would be an important step in ecoregion conservation.

Types and Severity of Threats

This mosaic of ecosystems which occupies the foothills is characterized by intensive agricultural activity. Almost all areas suitable for field crops are plowed, and the grazing pressure on pastures is very high. Cotton cultivation in the foothill territories and Fergana Valley is particularly intense.

Desertification threatens the steppe zone of the lower mountain belt due to overgrazing and the subsequent degradation of vegetation. The middle mountain belt is continuously degraded because of forest cutting. This has accelerated recently due to economic problems. Due to extensive hay harvesting and overgrazing, floral diversity in most of the high mountain meadows is decreasing, while noxious and weed plant species become more common. Destruction of natural habitats leads to the extinction of many common species. Throughout the ecoregion, the diversity and density of ungulates, predators and birds of prey have been seriously affected by poaching and improperly managed hunting tourism.

Justification of Ecoregion Delineation

This ecoregion includes the piedmont and low mountains of the Alai-Turkistan and West Tian Shan regions. The Ferghana valley is also included since, without irrigation, it would revert to its original steppe vegetation.

Additional information on this ecoregion

Further Reading

  • Syroechkovskii, E.E. 1990. Zapovedniks of central Asia and Kazakhstan. In Sokolov, V.E., editor. Zapovedniki of the USSR, Volume 6., Moscow.
  • Kamelin, R.V. 1990. Flora of the Syrdaryan Karatau. Materials to the floristic zonation of Central Asia. (Flora Syrdaryinskogo Karatau), Leningrad.
  • Kamelin, R.V., and E.P.Korshunova. 1990. Zapovednik Nurata. Pages 233-246 in V.E. Sokolov, editor. Zapovedniki of the USSR, Volume 6., Moscow.
  • Ladygina, G.M., and N.P. Litvinova. 1990. Obzornoe kartographirovanie rastitelnosti gor Srednei Azii ejegodnik Geobotanicheskoe kartographirovanie.
  • Kovshar, A.F., and A.A. Ivaschenko. 1990. Zapovednik Aksu-Dzhebagly. Pages 80-101 in V. E. Sokolov, editor. Zapovedniki of the USSR, Volume 6., Moscow.
  • Pereladova, O., V. Krever, and M. Williams. 1998. Biodiversity conservation in Central Asia. Moscow.
  • Rachkovskaya, E.I. 1995. Kazakhstan semi-deserts and melkosopochnik. Vegetation Map of Kasakhstan and Middle Asia. Scale 1:2 500 000. Komarov Botanic Institute, Russian Academy of Sciences, Sankt Peterburg.
  • Sokolov, V.E., and V.S. Skulkin. 1990. Zapovednik Chatkal. Pages 292-303 in V.E. Sokolov, editor. Zapovedniki of the USSR, Volume 6., Moscow.
  • Sokolov, V.E., Y.N. Chichikin, and A.A. Tishkov. 1990. Zapovednik Sary-Chelek. Pages 351 –362 in V.E. Sokolov, editor. Zapovedniki of the USSR, Volume 6., Moscow.

 

 

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.

 

 

 

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Citation

Fund, W. (2014). Alai-Western Tian Shan steppe. Retrieved from http://www.eoearth.org/view/article/149939

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