Description
Location and General Description
The southern deserts stretch from the eastern Caspian coast (to the west) to the middle current of Syr Darya (to the east) and to the foothills of the Central Asian mountains. The southern deserts include the Caspian coastal plains, the southern part of Ustyurt Plateau, Krasnovodsk Plateau, Kara Kum sandy deserts, and the southern part of Kyzyl Kum sandy desert (Rachkovskaya 1995). The climate of the Southern deserts has some indications of a transition to subtropical system. The characteristic feature is the considerable heat supply generated by the average annual temperature (~16º C) which is considerably higher than in the northern deserts. The pattern of precipitation is typical of the Mediterranean region. Annual precipitation of this ecoregion is 125-70 mm with most falling during winter, spring and partly fall. Rains almost never occur in the middle of summer, causing a prolonged summer pause in biotic activity. Winters are mild with the average temperature in January being –1 to 5º C. In the southern deserts a prolonged snow cover rarely occurs. Shorter duration snows are possible from the middle of December to the end of February.
Sands occupy large areas in the Southern Deserts. Two great Asian deserts, the Kara Kum and Kyzyl Kum, are located here. In addition to the denuded, arid plateau (Ustyurt) and low alluvial and delta-alluvial plains of Amu Darya, the Tedzhen, Murghab, and Zeravshan rivers are located here. There are some low mountains (760-920 m) on Paleozoic rocks in Kysyl Kum. The elevated, inclined foothill plains are typically in the south while low solonchak plains occupy the Caspian coast and depressions.
The southern deserts are distinguished from the northern deserts by changes in the structure of dominant plant species and an increase in the diversity of ephemeroids and ephemers. This difference is connected to a mild winter and early spring in the Southern Deserts. The green aspect of ephemers (Bromus spp., Malcolmia spp., Koelpinia spp., Amberboa spp.) and ephemeroids (Eremurus spp., Rheum spp., Tulipa spp., Gagea spp.) dominates in March and April. By the end of May these plants finish their annual growth. The summer is a time of a long drought.
The community structure of desert vegetation is closely associated with edaphic conditions. White saxaul (Haloxylon persicum) and black saxaul (Haloxylon aphyllum) occupy large areas on the sands. Saxaul is a high shrub (3-10 m). There are many endemic species found in sand the regions typical of the Southern Deserts (e.g., Salsola richteri, S. subaphylla, Ephedra strobilacea Ferula foetida). Sandy acacia (Ammodendron conollyi) grows on barkhans (sand-hills). In this region a diversity of shrub species such as Calligonum leucocladum, C. eriopodum, and C. setosum is great.
White salsola (Salsola arbuscula) and sagebrushe communities with a number of endemic species (Artemisia kemrudica, A. diffusa, A. dimoana, A. arenicola, Mausolea eriocarpa) are widespread on thin sandy soils and loamy sands. The presence of original desert types that are dominated by the endemic Astragalus vilosissimus and shrub bindweed (Convolvulus hammada) are characteristic for the east part of region. The perennial saltworts (Salsola gemmascens, S. orientalis) dominate on clay soils. Halophytic, succulent semishrubs such as Halostachys caspica, Halocnemum strobilaceum, Suaeda microphylla, and Salsola dendroides, grow on solonchaks.
Biodiversity Features
The fauna of deserts is characterized by a high degree of endemism. Especially rich is the fauna of sandy deserts. Among insects, the characteristic groups include grasshoppers, darkling beetles, scarabaeid beetles, butterflies, termites, and ants. The reptiles are numerous in deserts, and the majority of species inhabiting these ecosystems are autochthonous and belong to the core of the Central Asian herpetofauna
The most common desert mammals are the long-eared hedgehog (Erinaceus auritus), long-quilled hedgehog (Piracohinus hypomelas), and tolai hare (Lepus tolai). A variety of rodents such as gerbils (Rhombomys spp., Meriones spp.), and more than ten species of jerboas (Allactaga, Dipus, Paradipus, Eremodipus, Stylodipus) also live here. The characteristic components of desert ecosystems are such rare and disappearing mammal species as the honey badger (Mellivora capensis), sand lynx (Felis caracal), sand cat (Felis margarita), onager (Equus hemionus), goitered gazelle (Gazella subgutturosa), and marbled polecat (Vormela peregusna).
Endemics include the desert dormouse (Selevinia betpakdalensis), comb-toed jerboa (Paradipus ctenodactylus), three-toed and five-toed dwarf jerboas (Salpingotus heptneri, S. pallidus). Also endemic are several mammalian genera, such as Diplomesodon, Spermophilopsis, Pyderethmus, Allactodipus, Eremodipus and many others. Rare cats include Pallas’ cat (Otocolobus manul), cheetah (Acinonyx jubatus) which is extinct from the ecoregion, and the small sand cat which is restricted to dune areas with saxaul tree.
The common birds are larks (Calandrella spp., Galerida spp.), wheatears (Oenanthe isabellina, O. deserti), desert warbler (Sylvia nana), desert lark (Ammomanes deserti), desert raven (Corvus ruficollis), saksaul jay (Podoces panderi), desert shrike (Lanius excubitor), and desert sparrow (Paser simplex). Larger birds of the ecoregion include the houbara bustard (Chlamydotis undulata), black-bellied and pin-tailed sandgrouse (Pterocles alcata, P. orientalis), cream-colored courser (Cursorius cursor), golden eagle (Aquila chrysaetus), short-toed eagle (Circaetus gallicus), steppe eagle (Aquila rapax), Egyptian vulture (Neophron percnopterus), and saker falcon (Falco cherrug). Pander’s ground jay or saxaul jay (Podoces panderi) is a rare and unusual member of the crow family. The Asian desert sparrow (Passer zarudnyi) is also rare.
Reptiles and amphibians include: Khentau toad agama (Phrynocephalus rossikowi), Molchanov's toad agama (P. moltschanovi), Strauch's toad agama (P. strauchi), spotted toad agama (P. maculatus), Sogdian toad agama (P. sogdianus), Said-Aliev's toad agama (P. helioscopus saidalievi); gekkos (Alsophylax pipiens, A. laevis), Rustamov's skink gekko (Teratoscincus scincus rustamovi), Chernov's snake-lizard (Ophiomorus chernovi), Ferghana sand lizard (Eremias scripta pherganensis), black-eyed lizard (Eremias nigrocellata), gray monitor (Varanus griseus), Afghan lytorhynch (Lytorhynchus ridgewayi), and the cobra (Naja naja oxiana).
Current Status
Nature Reserves Description Country
Year Established Area in hectares
Tigrovaya Balka, Vahsh, Piandj river valleys Tajikistan 1938.
49,793
Amu Darya Reserve Amudaria river valleys, middle reaches Turkmenistan
1982 48,506 ha,
Kyzylkum Reserve Amudaria river valleys middle reaches Uzbekistan
1971 10,141ha
Repetek Reserve,
Sandy deserts Turkmenistan
1928. 34,600 ha,
Flora and fauna of the sand deserts are particularly vulnerable to human disturbance. Species associated with saksaul are disappearing rapidly, as saksaul forests are illegally cut for heating and cooking needs. Fortunately, serious reforestation measures are taking place in Turkmenistan (e.g., forest planting, gas provisions for heating and cooking to minimize fuelwood extraction, etc.).
Repetek has been a UNESCO biosphere reserve since 1978 and encompasses 34,600 hectares. Shakhsenem, Kelif, Zauaboiski, and Sarakamysh serve as wildlife refuges. Unfortunately, the current social and economic difficulties in Turkmenistan and Uzbekistan have caused a sharp decrease in funding for nature reserves, making proper function difficult. Other protected areas included in the table combine the conservation of fragments of southern deserts with riparian forests. There are few protected areas that support self-sustainable development of desert ecosystems.
Types and Severity of Threats
The main anthropogenic threats are agriculture, especially irrigated cotton production, hunting and poaching, and the overuse of woody plants for firewood and silk production. Overgrazing of livestock occurs in non-irrigated areas. Unregulated construction of roads threatens especially fragile desert ecosystems.
Saksaul and other trees and shrubs are cut extensively for fuel wood. In the last five to seven years, the area covered by saksaul has decreased by half, leaving the topsoil prone to erosion. The reduction of native species has encouraged the spread of desert moss (Tortula desertorum), which provides no nutritional value for wildlife and prevents the re-seeding of higher forms of native plants.
Some forms of wildlife, particularly reptiles, are collected and exported to zoos or collectors. The capture of venomous snakes has dramatically reduced the numbers of rare species such as the Central Asian cobra (Naja naja oxiana) and sand echis (Echis carinatus) as well as many common species.
Justification of Ecoregion Delineation
These deserts are located in southwestern Central Asia and encompass the majority of Turkmenistan and central Uzbekistan. They are distinguished from the northern deserts in that they are warmer with more seasonal rainfall which encourages the growth of ephemerals. Plant species have a much stronger Irano-Turanian character (Suslov 1961) than the deserts to the north. Sand acacia communities with their accompanying biological richness are much more abundant in the southern deserts. The area of this ecoregion includes the southern deserts of the Usturt and Mangishlak, Karakum and Kyzylkum (Pereladova et al. 1998).
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Prepared by:K. Rachkovskaja, O. Pereladova
Reviewed by: In process