Location and General Description
The ecoregion stretches from the Ural River and the border of the Caspian lowland up to east border of the Kazakh melkosopochnik. It includes the Lower Ural plateau and the northern part of the Turan lowland (near the Aral Sea). Also included is the southern part of the Turgay plateau which consists of plains and hills that are characteristic of melkosopochnik.
The climate is dry with a mean annual precipitation of 160 – 240 mm. The mean annual daily temperature is ~10oC. The contrast between summers and winters is extreme. The summers are hot while the winters are long, cold and severe. The average temperature in January is –13o to -16oC whereas in July the range is 21o to 24oC. The sharp fluctuation of climatic conditions is typical.
The relief of this ecoregion is highly variable. There are plateaus formed from chalk and Tertiary deposits, vast areas of melkosopochnik on a Paleozoic base, and alluvial plains. Soils are usually either light brown soils or desert brown soils. Varying degrees of salinity create a mosaic of plant communities.
Bunch grasses such as kovylok (Stipa lessingiana), tyrsik (Stipa sareptana), and tipchak (Festuca valesiaca) dominate in the desert steppes. Sagebrushes (Artemisia lerchena, A. lessingiana – to the west and Artemisia gracilescens, A. sublessingiana – to the east) constitute a significant portion of the plant communities. Forbs are not common and are mostly xerophytes (e.g., Pyrethrum achilaefolium, Linosyris tatarica, L. villosa) (Karamysheva & Rachkovskaya 1973). Large areas on the alluvial saline plains are characterized by halophytic plant communities including Artemisia pauciflora, A. schrenkiana, A. nitrosa and perennial saltwort (Atriplex cana, Anabasis salsa, and Camphorosma monspeliaca).
The processes of desert pedogenesis are distinctly expressed in the southern part of the ecoregion. Highly saline solonez soils are dominant. Different types of sagebrush deserts (Artemisia terrae albae semiarida, A. sublessingiana) with characteristic grasses (Stipa sareptana, Stipa kirghisorum, and endemic Stipa richterana) can be found throughout the region. The distinctive feature of melkosopochnik vegetation is the abundance of shrubs (Caragana balchashensis, C. frutex, Spiraea hypericifolia). Artemisia arenaria and Agropyron fragile predominate on small sandy massifs (Rachkovskaya 1995). There are numerous rare plant species in the semidesert area of Kazakhstan (e.g., Artemisia lessingiana, Stipa richterana, Ferula feruloides, and Brachanthemum kasakorum).
Among the characteristic birds of the ecoregion are buntings (Emberizidae), especially red-headed bunting (Emberiza bruniceps), larks (Alaudidae), wheatears (Oenanthe), pipits (Anthus spp.), black-belleied sand grouse (Pterocles orientalis), and steppe eagle (Aquila rapax). Rare birds of the ecoregion are demoiselle crane (Anthropoides virgo), common crane (Grus grus), steppe eagle (Aquila rapax), Pallas’s sandgrouse (Syrrhaptes paradoxus), golden eagle (Aquila chrysactor), peregrine falcon (Falco peregrinus), saker falcon (Falco cherrug) and others.
Species included in the Red Data Book of Kazakhstan (1996) include Kazakhstan argali (Ovis ammon colium), Pallas’s cat (Otocolobus manul), and marbled polecat (Vormela peregusna). Numerous herds of saiga antelope (Saiga tatarica) still exist in the semi-desert areas. Previously there were millions of animals migrating to the steppe areas of the north during the summer and to the semi-deserts in the south during the winter. These populations still exist though their numbers have decreased significantly. Huge populations of saiga antelope, which lived in Kazakhstan (mainly Kalmikia), Uzbekistan, and Turkmenistan, are now fragmented; the semi-desert population of Kazakhstan is newly isolated. Groups of goitered gazelle (Gazella subgutturosa) inhabit the southern areas of the ecoregion but have never established population densities as high as the saiga.
Large predators are still numerous indicating the diversity of fauna is still healthy. Wolf (Canis lupus) populations are still high with foxes (Vulpes vulpes) and badgers (Meles meles) also common.
Kazakhstan semi-deserts are historic areas for the Przewalskii horse (Equus przewalskii), which has not been sighted in the wild since 1968 (Macdonald 1999). The large semi-desert areas are not cultivated thereby maintaining suitable habitat for later reintroduction of this highly endangered species.
There are no strictly protected areas in the ecoregion. Some refuges do not adequately conserve constituent ecosystems. Within the last 10 years there has been an significant decrease in the number of domestic livestock all over Kazakhstan (about 10% of the previous number). As a result, ecosystems have a good chance for rehabilitation. This decrease in the number of the livestock has alternately increased wolf predation on saiga and large rodents.
Types and Severity of Threats
In the semi-desert, where the overall quality of pasture lands is good, overgrazing takes place around the wintering sites of settlements and along the herd routes.
The main cause for the significant decrease in the saiga population was overhunting early in the 20th century. Thousands of males were killed in the open field, and bodies were left in place. Poaching was primarily to collect the horns, which made their way into the illegal market of supplying the practice of Traditional Chinese Medicine. Lower population densities and high prices for gas (needed to follow animals by motorbikes) ultimately made this type of poaching less profitable. The poaching that takes place now (for all ungulate species) is mainly for meat that is needed by the local people, especially in winter.
Justification of Ecoregion Delineation
Forming a belt across central Kazakhstan, this ecoregion represents the transition between steppe and true desert. The boundaries encompass the northern semi-deserts of the Central Kazakhstan and northern Aral regions (Pereladova et al 1998).
Karamysheva, Z.V. and E.I. Rachkovskaya. 1973. Botanical geography of the steppe part of central Kazakhstan, (Botanicheskaya geografiya stepnoi chasti tsentralnogo Kazakhstana). Leningrad.
Macdonald, D., editor. 1999. The encyclopedia of mammals. Barnes and Noble Books, New York.
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, Saint Petersburg.
The Red Data Book of Kazakhstan. "Konzhyk", Almata, 1996.
Prepared by: K. Rachkovskaja, O. Pereladova
Reviewed by: In process