Tugay is a form of
riparian forest
A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...
or
woodland
A woodland () is, in the broad sense, land covered with trees, 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 sunlight and limited shade (see ...
associated with
fluvial
In geography and geology, fluvial processes are associated with rivers and streams and the deposits and landforms created by them. When the stream or rivers are associated with glaciers, ice sheets, or ice caps, the term glaciofluvial or fluviog ...
and
floodplain
A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...
areas in arid climates. These
wetlands
A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The ...
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, also known as Middle Asia, is a subregion, region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes t ...
. Because Tugay habitat is usually linear, following the courses of rivers in arid landscapes, Tugay communities often function as
wildlife corridors. 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 Northwest 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, China." Hydr ...
in north-western China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
, where the Tarim Huyanglin nature reserve in the middle reaches of the Tarim River
The Tarim River ( zh, p=Tǎlǐmù Hé, c=塔里木河; ug, تارىم دەرياسى, Tarim deryasi), known in Sanskrit as the Śītā, is an endorheic river in Xinjiang, China. It is the principal river of the Tarim Basin, a desert region of C ...
holds the largest areas of intact Tugay forests, with a 1993 estimate of about 61% of the total. The Central Asia
Central Asia, also known as Middle Asia, is a subregion, region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes t ...
n countries hold another 31%, with smaller areas remaining in the Middle East
The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabian Peninsula, Arabia (including the Arabian Peninsula and Bahrain), Anatolia, Asia Minor (Asian part of Turkey except Hatay Pro ...
and Pakistan
Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...
. Tugais also occur in the Caucasus
The Caucasus () or Caucasia (), is a region between the Black Sea and the Caspian Sea, mainly comprising Armenia, Azerbaijan, Georgia, and parts of Southern Russia. The Caucasus Mountains, including the Greater Caucasus range, have historically ...
.
Vegetation
Close to rivers and where groundwater
Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidate ...
levels are shallow, the vegetation is usually dominated by poplars
''Populus'' is a genus of 25–30 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to different species include poplar (), aspen, and cottonwood.
The we ...
(especially '' Populus euphratica'') and willow
Willows, also called sallows and osiers, from the genus ''Salix'', comprise around 400 speciesMabberley, D.J. 1997. The Plant Book, Cambridge University Press #2: Cambridge. of typically deciduous trees and shrubs, found primarily on moist s ...
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 Tam ...
, 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 angustifolia'', ...
will grow. Herbaceous plants include reeds, common spike rush, jointleaf rush, fleabane Fleabane is a common name for some flowering plants in the family Asteraceae.
Most are in the subfamily Asteroideae:
* ''Conyza'' (butterweeds or horseweeds: Astereae)
* ''Erigeron'' (Astereae)
* ''Inula'' ("yellowheads": Inuleae)
* ''Pluchea'' (ca ...
, cocklebur
''Xanthium'' (cocklebur) is a genus of flowering plants in the tribe Heliantheae within the family Asteraceae, native to the Americas and eastern Asia and some parts of south Asia .
Description
Cockleburs are coarse, herbaceous annual plants ...
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 bulrush or reedmace, in American English as reed, cattail, or punks, in A ...
''. Where the groundwater is deeper, oaks and elms
Elms are deciduous and semi-deciduous trees comprising the flowering plant genus ''Ulmus'' in the plant family Ulmaceae. They are distributed over most of the Northern Hemisphere, inhabiting the temperate and tropical-montane regions of Nor ...
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
See also
*Bosque
A bosque ( ) is a type of gallery forest habitat found along the riparian flood plains of stream and river banks in the southwestern United States. It derives its name from the Spanish word for 'woodlands'.
Setting
In the predominantly ar ...
, an analogous forest type in arid and semiarid regions of the southwestern United States
References
{{reflist
Forests
Deserts and xeric shrublands
Riparian zone
Wetlands