Desert types
The following types of deserts comprise landscape features of the cold winter deserts as Irano-Turanian (I) as well as Kazakh-Dzungarian semi-deserts and desert types (II):
Sandy deserts
Sandy deserts host the highest biodiversity in temperate deserts. In spring, after the maxima in precipitation, deserts become green and blossoming for a few weeks. It is inwrought by a diverse pattern of ephemeris (up to 150 species). Later they wither from drought stress and increasing mean daily temperatures and xerophytes and psammophytes dominate the landscapes, among others many species of scrubs of the genera Calligonum, Ammodendron or Aristida.
One of the special features of sandy deserts is extensive sites of saxaul shrubs (Haloxylon aphyllum and Haloxylon persicum), which are usually roughly to tamarisk or with Salsola-species, for instance, Carex physodes. Saxaul covers a variety of shrubs with a strong root system fixed in the sands, which can reach up to 8 m in a height and in exceptional cases even more. According to the Soviet classification, Saxaul stocks belong to woods.
Here and there strong winds cause large dunes and sandy ridges of up to 90 m height but on average they reach heights of 10-15 m.
Loess deserts
Loamy deserts are mainly distributed along the margins of the colline belt along the Central Asian high mountains Tian Shan and Pamir, in particular at the western exposed foothills. Through aeolic transport of predominantly western wind directions, sediments of periglacial, in parts alluvial genesis have been relocalized to the mountain foothills and accumulate there. The majority of the loamy particles are silt, very thin sized between 0.01 and 0.06 millimeters. Typical species are for instance Poa bulbosa, Iris songarica, Carex pachystylis and others.
Clay deserts
Because of the main soil components clay and silt, Clay deserts are characterized by extremely hard topsoil layers. Vast areas are polygonally burst in rigid plates. Clay deserts occur at several sites within the temperate deserts also abruptly within predominantly sandy deserts, like Karakum. Clay deserts are poor in terms of plant species. Occurring species are for example Salsola gemmascens, Gamanthus gamocarpus, Ephedra strobilacea, and others. They usually occupy fragments, pockets, and small depressions. Within takyrs, characterized by temporarily occurring high water tables, algae may grow as well as occasionally mosses.
Stone deserts
Stone deserts are large-scale landscapes with remaining clastic material and rocks as a result of mechanic erosion processes. Fine-grained sediments like sand, silt, or clay got deflated and are missing at large scale. Stony desert areas are almost free from vegetation. They appear in larger connected areas in the western part of Turkmenistan, in Balkan province until the Caspian Sea, and surround the shallow lake of Garabogaz.
Gypseous deserts
Large areas of the Ustyurt Plateau at the border triangle of Kazakhstan, Turkmenistan, and Uzbekistan are gypseous deserts. The Ustyurt Plateau is an elevated Plateau whose margins are delineated by up to 150 m steep cliffs surrounded by vast flat plains. At the plateau, there are elevations like Besshory, up to 556 m above sea level as well as depressions as low as -132 m, thus much lower than the average sea level. Often patches of gypseous deserts appear within other desert forms. That’s why it is difficult to draw a distinct distribution map. Common plant species in gypseous deserts are Anabasis salsa, Salsola spp., Artemisia terra-albae, and others. In general gypseous deserts are very diverse in terms of species. An unfavorable feature of gypseous deserts is its very low productivity of fodder plants and following a very low carrying capacity as pastures.
Salt deserts (Solonchaks)
Salt deserts have distinct halomorphic soils with in parts high ground water tables and temporarily appearance of salt lakes. They are found particularly adjacent to the shore line of Caspian Sea, along ancient waterformed depressions or at the northern and nowadays eastern shore of Aral Sea, as well as along the major river courses of Central Asia, the Amu-Darya and the Syr-Darya. The soil composition depends mostly on salt content and the respective ground water tables. Only salt tolerant plant species – so called halophytes – survive at these sites, like Salicornia, Halocnemum, Suaeda and others.
Riparian forest within temperate deserts
An azonal peculiarity in temperate deserts of Central Asia are large inland watercourses, most of all Amu Darya and the Syr Darya but not to forget also Ili, Zarafshan, Murgab, and others. These so-called Tugai forests represent important migration stopovers and watering sources for ungulates but also for migratory birds. At the same time, they are periodically inundated and therefore accumulated the most fertile soils in the whole desert region. For that reason, they are historically the most densely populated area in Central Asia. Typically here occurring tree species are Eleagnus Angustifolia, Ulmus pumila, and Populus euphratica.
