Tugai
As Tugai (sometimes Tokai, Togai, TouGai or Turau, Russian Тугай , Chinese Huyanglin ) is the typical form of vegetation Central Asian floodplains referred consisting of a mosaic of riparian forests ( Tugaiwald ), bushes and reeds there. The alluvial forests are predominantly characterized by the Euphrates poplar ( Populus euphratica ). Within the desert and semi-deserts of Central Asia, Tugais are among the habitats with the highest biodiversity; the animal species found here include pheasant , bukhara deer and big cat . In the second half of the 20th century in particular, large areas of Tugais were cut down and the sites were converted into irrigated agricultural areas. Not infrequently, a lasting disruption of the natural water balance and consequent drying up of rivers and desertification were the result.
description
Tugai forests are often characterized as gallery forests and show a sharply delimited transition to the adjacent desert or semi-desert landscapes. The type of character is the Euphrates poplar ( Populus euphratica ), which forms dense stands especially on nutrient-rich alluvial soils and is particularly dominant in the south. Additional possible as trees or shrubs more poplar species such as Populus pruinosa , Oleaster as Elaeagnus oxycarpa or Elaeagnus angustifolia , willow , tamarisk (mainly Tamarix ramosissima ), buckthorn and salt bush ( Halimodendron halodendron before). Creepers such as clematis and calystegia are common . Cattails , reeds , Apocynum species and in places ravenna grass are often found in the herb layer . In the southern Amu Darya region in particular , the reeds often reach heights of three meters.
On saline sites, tugais are mostly pronounced as thickets of the tamarisk species Tamarix ramosissima and Tamarix hispida . In addition, salt-loving plants such as Kalidium caspicum or salt herbs often appear here .
Occurrence
Tuga vegetation occurs on river courses and on river islands within the natural range of Populus euphratica . However, it is mainly found in the Aral Sea and Tarim Basins, i.e. on the river systems of Amu Darya , Syr Darya and Tarim . One of the main areas of distribution is in the Amu Darya river delta. To the east, the deposits extend into the Gobi .
Since tugais are mainly formed by phreatophytes - plants that get their water needs from the groundwater - they only occur in areas where the groundwater level is not lower than 10 m.
literature
- Niels Thevs: Ecology, Spatial Distribution, and Utilization of the Tugai Vegetation at the Middle Reaches of the Tarim, River Xinjiang, China , Cuvillier Verlag, Greifswald 2007, ISBN 3-86727-431-2
- Article Tugai in the Great Soviet Encyclopedia (BSE) , 3rd edition 1969–1978 (Russian) ( English )
Web links
- UN protection project in the Amudarya Delta in Karakalpakistan , accessed on August 8, 2011
- The destruction of the Tugai poplar forests in northwest China (PDF; 287 kB), accessed on August 8, 2008