Central Anatolian Steppe

Category: Grassland, Tundra, and Human Biomes.

Geographic Location: Middle East.

Summary: The central Anatolian steppe is a varied ecosystem that is home to a variety of unique halophytic flora.

Anatolia is a geo-historical term denoting the westernmost region of Asia on the Mediterranean coast, which has historically been home to Hittite, Persian, Greek, Assyrian, Armenian, Seljuk Turk, and Ottoman civilizations, and is currently composed primarily of the Republic of Turkey. The region is topographically diverse, including conifer and deciduous forests, temperate broadleaf mixed forests, sclerophyllous and mixed forests, and the montane conifer and deciduous forests around the Taurus mountains in the south.

The central Anatolian steppe is an ecosystem that includes marshes, rivers, freshwater and saline bodies, salt steppe, and halophytic vegetationvegetation adapted to saline conditions). It is one of the major centers of endemic plant species in Turkey and includes ten separate Important Bird Areas designated by BirdLife International as being important to a threatened-bird species. There are no highlands or mountains; the altitude averages 3,281 feet (1,000 meters), while plains and river basins are the dominant land formations. The prevailing climate is characterized by cold winters and long, hot, dry summers.

Three separate areas of steppe vegetation make up the ecoregion: Tuz Lake, the Karapinar Plain, and the combined Porsuk and Sakarya River basins. Tuz Lake, at the center of the region, is the second-largest in central Anatolia. The Kizilirmak River, the longest river fully contained within Turkey's boundaries, provides the northern and eastern borders of the Tuz Lake area as it flows along a very roundabout route into the Black Sea. The Karapinar Plain lies south of Tuz Lake, beyond the Obruk Plateau. The Haymana and Cihanbeyli plateaus separate Tuz Lake from the Porsuk and Sakarya Rivers. The entire steppe region is in turn surrounded by deciduous forest ecoregions. Very little woody vegetation grows in the central Anatolian steppethe soil and water are too saline, and the local flora is well adapted to the salt levels.

Tuz Lake is home to twelve endemic vascular plant taxa. In the summer, much of the lake dries up, exposing a thick layer of salt more than one foot (three meters) deep. Salt concentrations decrease further from the lake, so different species ranges have developed in concentric circles around the lake in bands that reduce salinity. Nearest the lake, where the water has most recently receded, is Salicornia europaea, which covers ninety-five percent of the ground in some parts of the steppe. This species is better known as common glasswort. Like other species of Salicorniasometimes known as samphire or sea beanis a succulent halophyte with small, scale-like leaves on jointed stems with many small branches. Glasswort is used as a food plant by both animals and humans and is noticeably salty and crisp.

Moving farther from the water, the next plant species is Halocnemum strobilaceum, which covers much of the ground in its band, followed by patches of Atropis distans, Limonium gmelinii, L. globuliferum, Juncus maritimus, and Plantago crassifolia, mixed in with more patches of glasswort and Halocnemum. The next vegetation band, in muddy, sandy soils, is a mix of Petrosimonia birandii and other Salicornia species. Beyond that,  Frankenia hirsuta, Kochia prostrata, Petrosimonia brachiata, Atriplex tatarica, and Salsola vermiculata are on the slopes around the lake. Finally, at the least-saline fringes, are more than a dozen additional salt-tolerant species, such as Salsola inermis, Aelropus lagopoides, Camphorosma monspeliaca, and Limonium iconium.

In the Karapinar plains, the soil is less saline, and Limonium anatolicum is dominant. Marsh meadows are formedwith Juncus maritimus, Limonium globuliferum, and Tamarix gracilis, and reeds and cyperus dominate in the freshwater areas. Many of the cyperus communities have a large number of endemic species.  Juncus heldreichanus, Aeolropous litoralis, and Pucinella convulata thrive where the water table is high.

Threatened Species

Threatened avian species in this biome include both the great and little bustard. Larks are common and represented in at least six species, of which the Asian short-toed lark (Calandrella cheleensis) is restricted to the fringes of the salt lakes in the central plateau. Birds living in one of the region's ten Important Bird Areas and key to conservation include the pygmy cormorant, white pelican, Dalmatian pelican, little bittern, squacco heron, purple heron, glossy ibis, greater flamingo, spoonbill, marbled teal, red-crested pochard, ferruginous duck, white-headed duck, pallid harrier, lesser kestrel, crane, collared pratincole, Kentish plover, greater sand plover, spur-winged plover, gull-billed tern, and little tern.

Threatened nonavian fauna species include the marbled polecat. Other mammals that range here include the golden hamster, badger, and gray wolf. Dominant reptiles are Agama stellio, Mabuya aurata, Typlops vermicularis, Coluber najadum, and C. numnifer. Phoxinellus crassus is an endemic fish of the Tuz Lake basin, living in the streams that feed into the lake.

The primary threat to the ecological sustainability of many of these species and the region is the overconsumption of freshwater resources. Recent studies have documented that Turkey's prolonged drought and increased water demands have caused Tuz Lake to shrink dramatically, with satellite imagery showing the lake's area has decreased by more than thrity percent in the past decade, threatening the breeding grounds of thousands of flamingos. Hydroelectric dam construction and the diversion of water for agricultural irrigation and civil engineering use have made an increasing impact across the region.

Bibliography

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Isik, Kani. "Seasonal Course of Height and Needle Growth in Pinus Nigra Grown in Summer-Dry Central Anatolia." Forest Ecology and Management, vol. 35, no. 3-4, July 1990, pp. 225-37.

Kahveci, Gulzade. "General Characteristics and Forest Relics in Central Anatolia." Forestist, vol. 72, 11 May 2022, pp. 192-98, doi.org/10.54614/forestist.2022.21056. Accessed 17 July 2022.

Kirwan, Guy, et al. The Birds of Turkey. A&C Black, 2009.

Ocel, Isil, et al. "Role of Antioxidant Defense System and Biochemical Adaptation on Stress Tolerance of High Mountain and Steppe Plants." Acta Oecologica, vol. 26, no. 3, Dec. 2004, pp. 211-18.

Şimşek, C., and A. Baba. "Impact of Climate Change and Anthropogenic Effects on Turkish Lakes: A Case Study of Tuz Lake." Environmental Monitoring and Assessment, vol. 195, no. 11, 2023, pp. 1-15. Accessed 9 Nov. 2024.