Takla Makan Desert ecology

Category: Desert Biomes.

Geographic Location: Asia.

Summary: Takla Makan in northwestern China is the world’s second-largest shifting-sand desert. Despite its dry surface, the desert holds precious resources such as ground­water and oil.

The Takla Makan Desert is located in the Xinjiang Uyghur Autonomous Region, in the northwestern area of the People’s Republic of China. Classified as a hyperarid region, it includes xeric (drought-tolerant) shrublands at its edges.

The Tarim Basin is bordered by the Tian Shan Mountains to the north, the Kunlun and Altun Mountains to the south, and the Pamirs to the west. In the center of the Tarim Basin extends the Takla Makan Desert, covering an area of about 129,344 square miles (335,000 square kilometers). While elevations of 3,937 feet (1,200 meters) and even 4,921 feet (1,500 meters) above sea level can be reached, the lowest point is 505 feet (154 meters) below sea level. Based on the classification protocols in use by China, the region is demarked as desert steppe, shrubby and rocky desert with sand dunes, saline soil, and sparsely vegetated areas. As a part of Xinjiang, the Takla Makan is earthquake-prone.

Alluvial deposits from glacial watercourses provide the basic stratum, which is covered with a thick layer of sand. More than 100 mummies, some 4,000 years old, and Buddhist artifacts have been found in the region, proving early human habitation. Unusual, complex wind conditions in the basin form a variety of eolian, crescent-shaped sand dunes that make up 85 percent of the desert area. Larger sand-dune chains average 98–492 feet (30–150 meters) in height and span 787–1,640 feet (240–500 meters) in width, with a distance between the dune chains of 0.6–3 miles (1–5 kilometers). Some are 984 feet (300 meters) high, sculpted by erosive removal of sand, called denudational shapes. Depressions consist of gravel, sand, silt, or clay brought here by water, called depositional shapes. Saltmarsh and saltflats can also be found among the dunes.

Climate

Especially in the spring when the surface sand heats up, ascending air currents develop, and due to the wind-tunnel effect of the surrounding mountains, hurricane-force dust storms blow from the northeast. This is the season of the Kara Buran, the black sandstorm. Year round, constant winds keep the sand moving. Each year the dunes shift about 492 feet (150 meters), which endangers the continuing existence of oases here. The Takla Makan is considered to be China’s warmest desert. Average temperatures are 77 degrees F (25 degrees C) in summer and 14 degrees F (minus 10 degrees C) in winter, with peaks of 115 degrees F (46 degrees C) and lows of minus 4 degrees F (minus 20 degrees C).

Located in an extreme inland position, the desert lacks any balancing influence from warm maritime air. Before air masses from the oceans reach central Asia, they lose their humidity, resulting in cold nights even during summertime, and extremely scant precipitation, below 1.5 inches (38 millimeters) per year. Some areas receive less than 0.5 inch (13 millimeters) of precipitation per year. The Tarim Basin is an internal drainage, or endorheic, basin. Perennial freshwater springs are fed by snowmelt from the Kunlun and Tian Shan mountains. Some rivers penetrate about 62–124 miles (100–200 kilometers) into the desert, gradually drying up in the sands. The Tarim River flows along the edge of the desert in an east-west direction.

Biodiversity

The Takla Makan Desert is mostly uninhabited; it is also almost entirely devoid of vegetation and fauna. Only a few, very specialized species live here, such as the Asiatic wild ass. In the Lop Nur Basin, east of the now-dry Lop Nur Lake, live the last 500 wild bactrian camels. Bactrian camels store water in their humps and can survive for months without drinking. The Arjin Shan Nature Reserve, at some 5,840 square miles (15,125 square kilometers), has been established in this area to conserve habitat for this species, but wild camels as well as Asiatic wild asses are still declining. Around oases, people cultivate fruit trees and other types of crops. Native plants include tamarisk, nitre bushes, and reeds. Alhagi sparsifolia is a leguminous perennial desert plant able to absorb atmospheric nitrogen. As a fodder plant, it provides protein to livestock in the desert region. Its deep, extensive root structure helps prevent sand erosion.

All plants that grow here tolerate storms, extreme temperatures, and salt. Turanga poplar, oleaster, camel thorn, members of the Zygophyllaceae (caltrop) family, and saltworts grow along the edges of the desert, near river valleys. Each species developed a unique survival strategy. In low basins, the shallow groundwater lies only 10–15 feet (3–5 meters) below the surface; some plants’ root systems can tap this.

Human Activity and Environmental Threats

The desert’s rich natural oil reserves have been exploited since the 1950s. The Chinese government has encouraged settlement in the region, founding the city of Korla. Many trees were planted to reduce the encroachment of the sand. Today, the desert is the headquarters of Tarim Oilfield Co., a unit of PetroChina.

To transport the oil, three desert roads were built from 1995 to 2007, including the world’s longest desert road. When that road, the 324-mile (522-kilometer) long Tarim Highway, first opened in 1995, Chinese officials had problems keeping blowing sand dunes from covering the road. Their solution was to build a “green belt” of shrubs and other vegetation along both sides of the highway. The vegetation is irrigated by solar-powered pumps.

The present population consists largely of Turkic Uyghur and recently settled Han people. An increasing population uses more water for crop irrigation than is available. Lakes and rivers have dried out through irrigation, threatening the existing oases. Furthermore, the yields drop after a few years. Fields turn into desert rather than reverting to grassland. Oversize herds overgraze the land, further intensifying soil depletion, and making natural regeneration virtually impossible. Climate change impacts may be felt in increasing sandstorms throughout the area, as well as other potential changes including warmer temperatures and even scarcer precipitation.

Bibliography

Arndt, Stephan, et al. “Contrasting Patterns of Leaf Solute Accumulation and Salt Adaptation in Four Phreatophytic Desert Plants in a Hyperarid Desert with Saline Groundwater.” Journal of Arid Environments 10 (2004).

Eyre, S. Robert, ed. World Vegetation Types. New York: Columbia University Press, 1971.

Ruiz, Mauricio. “Modernization of China’s First Desert Highway to Reduce Carbon Emissions.” Travel Tomorrow, 15 June 2022, traveltomorrow.com/modernization-of-chinas-first-desert-highway-to-reduce-carbon-emissions/. Accessed 31 Aug. 2022.

Warner, Thomas. Desert Meteorology. Cambridge, UK: Cambridge University Press, 2004.