Tugay is a form of riparian

forest A forest is an ecosystem characterized by a dense ecological community, community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, ...

woodland A woodland () is, in the broad sense, land covered with woody plants (trees and shrubs), or in a narrow sense, synonymous with wood (or in the U.S., the '' plurale tantum'' woods), a low-density forest forming open habitats with plenty of sunli ...

associated with fluvial and

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river. Floodplains stretch from the banks of a river channel to the base of the enclosing valley, and experience flooding during periods of high Discharge (hydrolog ...

areas in arid climates. These

wetlands A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially ...

are subject to periodic inundation, and largely dependent on floods and groundwater rather than directly from rainfall. Tugay habitats occur in semi-arid and

desert climate The desert climate or arid climate (in the Köppen climate classification ''BWh'' and ''BWk'') is a dry climate sub-type in which there is a severe excess of evaporation over precipitation. The typically bald, rocky, or sandy surfaces in desert ...

s in

Central Asia Central Asia is a region of Asia consisting of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. The countries as a group are also colloquially referred to as the "-stans" as all have names ending with the Persian language, Pers ...

. Because Tugay habitat is usually linear, following the courses of rivers in arid landscapes, Tugay communities often function as

wildlife corridor A wildlife corridor, also known as a habitat corridor, or green corridor, is a designated area habitat (ecology), that connects wildlife populations that have been separated by human activities or structures, such as development, roads, or land ...

s. They have disappeared or become fragmented over much of their former range.

Distribution

The centre of the range of Tugay vegetation is the

Tarim Basin The Tarim Basin is an endorheic basin in Xinjiang, Northwestern China occupying an area of about and one of the largest basins in Northwest China.Chen, Yaning, et al. "Regional climate change and its effects on river runoff in the Tarim Basin, Ch ...

in north-western

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

, where the Tarim Huyanglin nature reserve in the middle reaches of the Tarim River holds the largest areas of intact Tugay forests, with a 1993 estimate of about 61% of the total. The

n countries hold another 31%, with smaller areas remaining in the

Middle East The Middle East (term originally coined in English language) is a geopolitical region encompassing the Arabian Peninsula, the Levant, Turkey, Egypt, Iran, and Iraq. The term came into widespread usage by the United Kingdom and western Eur ...

and

Pakistan Pakistan, officially the Islamic Republic of Pakistan, is a country in South Asia. It is the List of countries and dependencies by population, fifth-most populous country, with a population of over 241.5 million, having the Islam by country# ...

. Tugais also occur in the

Caucasus The Caucasus () or Caucasia (), is a region spanning Eastern Europe and Western Asia. It is situated between the Black Sea and the Caspian Sea, comprising parts of Southern Russia, Georgia, Armenia, and Azerbaijan. The Caucasus Mountains, i ...

Vegetation

Close to rivers and where

groundwater Groundwater is the water present beneath Earth's surface in rock and Pore space in soil, soil pore spaces and in the fractures of stratum, rock formations. About 30 percent of all readily available fresh water in the world is groundwater. A unit ...

levels are shallow, the vegetation is usually dominated by poplars (especially '' Populus euphratica'') and

willow Willows, also called sallows and osiers, of the genus ''Salix'', comprise around 350 species (plus numerous hybrids) of typically deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions. Most species are known ...

s such as '' Salix songarica''. Where the forest has been disturbed, other species such as

tamarisk The genus ''Tamarix'' (tamarisk, salt cedar, taray) is composed of about 50–60 species of flowering plants in the family Tamaricaceae, native to drier areas of Eurasia and Africa. The generic name originated in Latin and may refer to the Tamb ...

, sea-buckthorn and

oleaster , signifying a plant like an olive, but less valuable (cf. poetaster), may be applied to: *Feral olive trees that have been allowed to run wild *'' Olea oleaster'', the wild olive *Various species of '' Elaeagnus'', notably '' Elaeagnus angustifoli ...

will grow. Herbaceous plants include reeds, common spike rush, jointleaf rush, fleabane, cocklebur and thorn apple. Grass tugai vegetation is dominated by '' Phragmites australis'', '' Calamagrostis'' and ''

Typha ''Typha'' is a genus of about 30 species of monocotyledonous flowering plants in the family Typhaceae. These plants have a variety of common names, in British English as bulrushStreeter D, Hart-Davies C, Hardcastle A, Cole F, Harper L. 2009. ' ...

''. Where the groundwater is deeper, oaks and elms will dominate.British Petroleum. 2002. "Ecological Baseline Report". BTC Pipeline ESIA, Azerbaijan. Retrieved 2013-03-30. The principal causes for the loss of tugai vegetation include dam construction, tree cutting, grazing, and agriculture.

Notes

References

{{reflist Forests Deserts and xeric shrublands Riparian zone Wetlands

Distribution

Vegetation

Notes

See also

References