Central Asian riparian woodlands
These forest galleries, locally known as tugai, are located on the floodplains of the major Central Asian rivers and function as a critical habitat for the surrounding arid lands. They are characterized by impenetrable thickets of trees entwined with lianas, patches of grassy clearings, and at times interspersed with wetlands. The tugai represent a virtual oasis for both resident and migratory wildlife. Main flyways for migrating birds pass through the water bodies in the riparian forests and serve as wintering sites, stops along the migration routes, and sites for colonial nesting. As many as 30 of up to 150 migratory birds are considered endangered or threatened. These riparian forests are severely threatened by anthropogenic activity. Restoration of relevant reserves is of great importance to the biological diversity and ecosystem function in the region.
Location and General Description
Widespread throughout the Central Asian desert and plains, tugai lines the shores of Central Asia's largest rivers, the Syr Darya, Amur Darya, Murghab, Tedzhen, Ili, Zeravshan, Vakhsh, and the Naryn rivers. Environmental conditions are extreme with the difference in summer and winter temperatures reaching 80º C in some areas. The annual precipitation in the plains does not exceed 300 millimeters (mm), as the main areas of the riparian forests are situated in the middle of the largest deserts of the region. Flooding cycles triggered by mountain snowmelt in spring and early summer are followed by periods of extreme drought and increased soil salinity. The regulation of water for agricultural development has caused most riparian forests to miss necessary flooding cycles and consequently suffer from overly dry conditions.
These woodlands represent a specific complex of woody-shrubby vegetation and high grasses, occurring only in the floodplains and river valleys of the Central Asian rivers. The tugai plant communities are comprised of the poplars (Populus diversifolia, P. pruinosa), dzhidda (Elaeagnus oxycarpa), willows (Salix spp.), and tamarix (Tamarix spp.) forests which alternate with meadows and reeds. Under the cover of dominant trees are shrubs such as Hippophae rhamnoides, barbel (Berberis spp.), briar roses (Rosa spp.), honeysuckles (Lonicera spp.), and Cotoneaster spp.. Along the lake shores, large areas are occupied by the reed (Phragmites spp.), cattail (Typha sp.), Erianthus, Tamarix, Halimodendron, and licorice (Glycyrrhiza spp.). The herbaceous vegetation is represented by steppe, desert, and swamp species. In the steppe zone, the ecosystems of willow and poplar forests alternate with various types of meadow and meadow-swamp ecosystems.
The diversity of vertebrate animals here is represented by common mammals such as dormouse (Dryomys nitidula), badger (Meles meles), wild boar (Sus scrofa), jackal (Canis aureus), tolai hare (Lepus tolai), serotine bat (Vespertilio serotinus), and Hemprich’s long-eared bat (Otonycteris hemprichi). In the northern areas the most common mammals are the forest mouse (Apodemus sylvaticus), badger (Meles meles), and wild boar (Sus scrofa), while in the south dominants include the tamarix gerbil (Meriones tamariscinus), flattooth rat (Nesokia indica), and jackal (Canis aureus). The Caspian (Turanian) tiger (Panthera tigris virgata) used to live in the tugai but has not been seen since 1958 and has since been declared extinct.
Among the common birds found in tugai forest ecosystems are shikra (Accipiter badius), pheasant (Phasianus colchicus), Bruce's scops owl (Otus brucei), scops owl (Otus scops), marsh harrier (Circus aeruginosus), kestrels (Falco tinnunculus, F. naumanni), penduline tits (Remiz coronatus, R. macronyx, R. pendulinuscrinatus), wagtails (Motacilla cinerea, M. personata), tits (Parus bokharensis, P. cyaneus, P. flavipectus), and cuckoo (Cuculus canorus).
Considerable numbers of wintering birds from Kazakhstan and western Siberia come here in winter. The main flyways pass through the riparian forests that serve as wintering sites, stops along the migration routes, and sites for colonial nesting. Only the list of migratory birds has more than 150 species of which about 30 are considered rare or endangered. The [[lake|lakes] serve as nesting sites for pelicans, cormorants, herons, and other aquatric birds; their numbers can reach tens of thousands of individuals. The wetland [[[ecosystem|ecosystems]] are especially important for the conservation of such rare aquatic birds as gulls (Larus brunicephalus, L. relictus), white-headed duck (Oxiura leucocephala), marbled teal (Anas angustirostris), flamingo (Phoenicopterus roseus), white and Dalmatian pelicans (Pelecanus crispus, P. onocrotalus), mountain goose (Anser indicus) and many other species.
Among the common amphibians and reptiles are: grey, green and Central Asian toads (Bufo bufo, B. viridis, B. danatensis); lake, grass, Siberian, and black-spotted frogs (Rana ridibunda, R. temmporaria, R. Amurrensis, R. nigrimaculata); Pelobates fuscus, Bombina bombina; swamp turtle (Emys orbicularis), Caspian turtle (Mauremys caspica); grey, Caspian, and Turkestan gekkos (Cyrtopodion russowi, C. caspis, C. fedtschenkoi), swift lizard (Eremias velox), desert and Asian skinks (Ablepharus deserti, A. pannonicus), and among snakes, Natrix natrix, N. tessellata, Elaphe dione, echis (Echis multisquamatus) and gyurza (Vipera lebetina).
Species less commonly seen include otter (Lutra lutra) and jungle cat (Felis chaus oxiana). In the tugais, rare mammals are Bukhara deer (Cervus elaphus bactricanus), hyena (Hyaena hyaena) which still exist in some tugai massifs in the south, and goitered gazelle (Gazella subgutturosa) which visit tugais from the desert. Among birds, species include the eastern stock dove (Columba eversmanni) which has recently become rare. Notable amphibians and reptiles are the Anatolian frog (Rana macrocnemis), Semirechye newt (Ranodon sibiricus), shielded gekko (Alsophylax loricatus), grey monitor (Varanus griseus) whose wintering places are located in the river cliffs, Central Asian cobra (Naja oxiana), and other snakes such as Ptyas mucosus, Lycodon striatus, and Coluber caspius.
The three species of Middle-Asian shovel-nosed sturgeons (Pseudoscaphirhynchus kaufmanni, P. hermanni and P. fedtschenkoi) have been included in the Red Data Book of the USSR and the problem of their conservation is acute in all Central Asian countries. The Amurdarya shovelnoses (P. kaufmanni and P. hermanni) have been included in the Red Data Books of Turkmenistan and Uzbekistan. Documents are being prepared to include these species in the IUCN Red List of Threatened Species. The Syr Darya shovelnose (P. fedtschenkoi) appears to no longer be found in this ecoregion.
|Table 1. Specially Protected Areas - Nature Reserves|
|Nature Reserves||Description||Country||Year Established||Area in hectares|
|Tigrovaya Balka,||Vahsh, Piandj river valleys||Tajikistan||1938||49,793|
|Amurdarya Reserve||Amurdaria river valleys, middle reaches||Turkmenistan||1982||48,506 ha,|
|Badai-Tugai Reserve||Amurdaria river valleys, lower reaches||Uzbekistan||1971||6,462 ha|
|Kyzylkum Reserve||Amurdaria river valleys, middle reaches||Uzbekistan||1971||10,141ha/about 5.000 ha riparian forests|
|Zerafshan Reserve||Zeravshan river valleys||Uzbekistan||1975||2.352 ha|
|Aral-Paigambar part of Surkhan reserve||Amurdaria river valleys, upper reaches||Uzbekistan||1971||3.097 ha|
|Altyn-Emel national park||Ily river valley||Kazakhstan||1996||459.627 ha/about 2.000 ha riparian forests|
|Karatchigil protected area||Ily river valley||Kazakhstan||about 5.000 ha riparian forests|
|Talass zakaznik||Talass and Karakol Rivers.||Kyrgystan||1986||2.500 ha|
These riparian woodlands are severely threatened through habitat destruction. Virtually no virgin forest remains today. The total area of riparian forests along Amur Darya previously was around 500 square kilometers (km2). That area has now been reduced to around 50 km2, of which not more then 10-15 km2 is in very good condition. Situated in the regularly flooded river valleys, the areas occupied by riparian forest present the most favorable agricultural lands of the region (both for the quality of the soils and possibility for watering). As a result many forest areas, especially in Uzbekistan and Turkmenistan, were cleared for cultivating cotton. The situation is better along the Syr Darya, which belongs primarily to Kazakhstan. Kazakhstan is a huge area of steppes that are ploughed for agriculture, while the country’s main specialization is wheat. The main threat is illegal logging to meet the personal needs (i.e., heating and cooking) of the local people.
A number of reserves have been established to protect tugai remnants. However, the size and management of these reserves is at present insufficient for long-term success of the tugais. The main problem is an insufficient supply of water resources due to a series of dams that provide water for the fields. Restoration both within and outside the reserves is urgently needed. Unfortunately, the current social and economic difficulties are likely to prevent this from happening in the short-term.
One of the best-known protected areas in Tajikistan is Tigrovaya Balka. It was established to protect the largest existing poplar tugai forest, numerous lakes and nearby semi-desert areas. In Uzbekistan, several reserves protecting small patches of tugai areas have been established. These include the Badai-Tugai Reserve in the lower portion of the Amurdarya River, the Kuzylkum Reserve in the middle portion of the Amur Darya, the Aral-Paigambar (currently a part of the Surkhan Reserve) in the upper portion, and the Zeravshan Reserve in the middle portion of the Zeravshan River. In Turkmenistan, the tugai ecosystems are protected in the Amur Darya Reserve. In Kirghizia, the tugai, characterized by Hippophae rhamnoides, are protected in the Talass Refuge along the Talass and Karakol Rivers. In Kazakhstan, riparian forests of the Ili river are protected in Altyn-Emel National Park and in Karatchigil (Special Governmental Protected Area).
Types and Severity of Threats
Overgrazing, agricultural conversion, and reduced river flow (resulting from irrigation canals and the cultivation of floodplains) have contributed significantly to the decline of many floodplain ecosystems and the desertification of river valleys. Cotton agriculture, which dominates in some states of the region, requires a high level of watering and rapidly leads to salinated soils. These areas then become badlands for agriculture, become unsuitable for ecosystem restoration, and require preliminary desalination for any future cultivation.
Major rivers such as the Amur Darya and Syr Darya are overexploited to the extent that their waters never complete their natural course. Overgrazing is a threat in many of the younger forests while the current fuel crisis has led to extensive cutting of trees and other woody plants. This removal of the forests is leading to erosion and significant fluctuations in river flow. Many rivers contain chemical fertilizers and high concentrations of heavy metals, carcinogens and harmful bacteria.
Additional Information on this Ecoregion
- For a shorter summary of this entry, see the WWF WildWorld profile of this ecoregion
- To see the species that live in this ecoregion, including images and threat levels, see the WWF Wildfinder description of this ecoregion
- World Wildlife Fund Homepage
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- Borodin, A.M. editor. 1985. Krasnaya Kniga USSR: Redkie i nokhodyashchiesya pod ygrozoi uschesnoveniya vidy zhivonykh i rastenii. Moscow: Lesnaya Promyshennost.
- Geptner, V., A. Nasimovich, and A. Bannikov. editors. 1988. Mammals of the Soviet Union: Artiodactyla and Perissodactyla. Smithsonian Institution Libraries and the National Science Foundation, Washington, D.C. ISBN: 3930612585
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- Krever, V., O. Pereladova, M. Williams, and H. Jungius. 1998. Biodiversity conservation in central Asia: An analysis of biodiversity and current threats and initial investment portfolios. World Wild Fund for Nature (WWF), Washington DC.
- Popov, V.A., T.A. Abdreimov, and A.A. Tishkov. 1990. Zapovednik Badai-Tugai. Pages 214-224 in V.E. Sokolov, editor. Zapovedniki of the USSR, Volume 6., Moscow.
- Rachkovskaya, E.I. 1995. Vegetation of Kazakhstan and Middle Asia (Desert region). Vegetation Map of Kasakhstan and Middle Asia. Scale 1:2,500,000. Komarov Botanic Institute, Russian Academy of Sciences, Saint Petersburg.
- Salimov, K.V., A.F. Faiziev, and A.A. Tishkov. 1990. Zapovednik Kyzylkumskii. Pages 225-232 in V.E. Sokolov, editor. Zapovedniki of the USSR, Volume 6., Moscow.
- Sokolov, V.E., G.N. Sapojnikov, and P.D. Gunin. 1990. Zapovednik Tigrovaya Balka. Pages 304-321 in V.E. Sokolov, editor. Zapovedniki of the USSR, Volume 6., Moscow.
- Sokolov, V.Y., and Y.Y. Syroechkovskii. 1990. Reserves of Central Asia and Kazakhstan. Mysl’, Moscow, USSR.
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