This unique region of the central Anatolian basin hosts salt steppe, saline lakes and halophytic vegetation as well as marshes, rivers and freshwater bodies. It represents one of the centers of endemism of the diverse Anatolian flora, with 12 vascular plant taxa endemic to the area's central lake. Ten Important Bird Areas, all wetlands, support a diversity of residents and migrants. Threatened birds include the great bustard and the little bustard. An endemic fish species lives in the basin, and threatened species such as the marbled polecat also inhabit the area. The principal threats are posed by diversion of the areas water resources and conversion to agriculture.
Location and General Description
This ecoregion is largely comprised of three separate areas of steppe vegetation in central Anatolia. The largest area is dominated by Tuz Lake and lies in the center of the Anatolian basin. The northern and eastern edges of this area are defined by a long arch in the K?z?l?rmak River, the biggest river in Anatolia. This arch starts from the Cankiri environs to the north of Tuz Lake and extends to the Nev?ehir environs in the east. The second area of this ecoregion lies in the Karap?nar Plain to the south of Tuz Lake and is separated from the central area by the Obruk Plateau. This area represents the southernmost reaches of the ecoregion. The Porsuk and Sakarya River basins comprise the third and westernmost area of the ecoregion, which is separated from the central area by the Haymana and Cihanbeyli Plateaus.
These three areas of central Anatolian steppe are almost completely enclosed within an area where deciduous forests represent the primary vegetation type. The principal feature that distinguishes this steppe region from the surrounding deciduous forests ecoregion is the absence here of any woody formations. This area is known as "true steppe"; the surrounding region is accepted as an anthropogenic steppe because it has lost its woody cover due to human activity.
There are no mountains or highlands here, and the average altitude is around 1,000 meters (m). Plains and river basins constitute the dominant land formations, with their boundaries determined by plateaus. The main geological formation of the area consists of young alluvial deposits. These are Oligocene formations of gypsum and saline. As in the surrounding deciduous forest region, the continental climate that prevails here is characterized by cold winters and hot, dry summers. Annual precipitation ranges from 400 to 500 millimeters (mm), decreasing to 300 mm in certain places depending on the micro-topography.
Salt steppes and lakes are the principal formations in this region. Tuz Lake is (max. 190,000 hectares [ha]), Tersakan Lake (6,400 ha), E?mekaya Marsh, (11,250 ha), and the Çumra, Ere?li, Çal?kdüzü and Karap?nar plains are the most representative examples of these formations. Because of the saline conditions, halophytic plants are favored and woody plants do not occur here. The most abundant species of the salt steppes belong to the Chenopodiaceae and Plumbaginaceae families.
Tuz Lake is also the second biggest lake in central Anatolia. It lies at an altitude of 829 m. and is fed by seasonal streams. During the summer, most of water in the lake dries up and exposes a 30-centimeter (cm) thick salt layer. Salt concentrations decrease from the inner to the outer areas of the lakebed and determine the type of the plant communities that grow. Thus, the most salt tolerant species grow near the center of the lakebed while Artemisia steppes are found near the periphery. Another feature that determines the nature of the plant communities in the area is the micro-topography, which affects the salt concentration in the soil. Depending on salinity levels, plant communities surrounding Tuz Lake can be described as follows, starting from the inner periphery:
- Salicornietum europaeae: This species is found in areas where the water has just receded; its cover value may reach up to 95% in some localities.
- Halocnemum strobilaceum: This is an almost monospecific genera whose cover value may reach up to 90%. Salsola stenoptera and Limonium iconicum may also occur with it.
- Atropis distans-Limonium gmelinii association: This association does not form a continuous belt but rather grows in patches; it is less halophilous than the species below. Other important components of this association are Limonium globuliferum, Juncus maritimus, Plantago crassifolia, Salicornia europaea, and Halocnemum strobilaceum.
- Petrosimonia birandii: This species grows in the muddy sandy soils close to the lake and may form associations with any of the following: Petrosimonia triandra, Salsola anatolica, Halocharis sulphurea, Salicornia herbacea, Kochia prostrata, Suaeda prostarta, Triplospermum praecox, Stipa hohenackeriana, S. lagascae, and Haplophyllum graveolens.
- Frankenia hirsuta-Limonium iconium association: This association can be seen on the gently sloping elevations around Tuz Lake. Some of the other component species are: Frankenia hirsuta, Limonium iconium, Reaumuria alternifolia, Salsola inermis, Camphorosma monspeliaca, Atropis distans, Limonium gmelinii, Halocnemum strobilaceum, Apera intermedia, Kochia prostrata, Petrosimonia brachiata, Salsola vermiculata, and Atriplex tatarica.
- Salsola inermis association: This association lies in the outermost belt of Tuz Lake and is adjacent to non-halophytic Artemisia steppe. It can also be seen near other lakes, such as Aci Lake and Tersakan Lake in the southern Ere?li region. Some of the other species in this association are: Salsola inermis, Aeluropus lagopoides, Camphorosma monspeliaca, Limonium iconium, Artemisia fragrans, Apera intermedia, Petrosimonia birandii, Kochia prostrata, Salsola anatolica, Salsola kali, Cynodon dactylon, Frankenia hirsuta, Bromus tectorum, Hordeum murinum, H. marinum, Agropyron cristatum, Atriplex lasiantha, Agrostis spica-venti, and Reaumuria alternifolia.
Due to the unique water regime here, the life cycle of the halophytic vegetation near the lake is completely different from that of the surrounding steppe vegetation. The flowering season of these halophytes lasts from August to October, when all other steppe formations are experiencing the dry season period of slow growth.
In the less saline conditions of the Karap?nar plains, Limonium anatolicum is dominant, accompanied by species such as Petrosimonia brachiata, Alhagi pseudoalhagi, Salsola crassa, Petrosimonia nigeensis and Frankenia hirsuta. Another common association in the region is Juncus maritimus-Limonium globuliferum, forming a kind of marsh meadow with Tamarix gracilis. In the freshwater areas and slightly saline marshes, reed (Phragmites australis) and cyperus (Juncus heldreichianus orientalis) are the dominant species. Cyperus communities in particular are distinctive due to their high endemism ratio.
Salt steppe and a shallow saline lake occupy the second area of this region, lying to the south of Tuz Lake. In places with a higher water table, Juncus heldreichanus, Aeloropous litoralis and Pucinella convulata form extensive communities. The salt steppes are dominated by Lepidium cartilagineum, Pandera pilosa, Sueda altissima, Frankenia hirsuta, Limonium liliacium and Acanthalimon halophilum.
|Table 1. Birds of conservation interest that occur in Important Bird Areas (IBAs).|
|Species||Scientific Name||European Threat Status||Criteria|
|Pygmy Cormorant||Phalacrocorax pygmeus||SPEC 3 Rare|| Moderate decline 1970-90,|
|White Pelican||Pelecanus onocrotalus||SPEC 3 Rare||<10,000 pairs|
|Dalmatian Pelican||Pelecanus crispus||SPEC 2 Vulnerable||<2,500 pairs|
|Little Bittern||Ixobrychus minutus||SPEC 3 Vulnerable||Large decline 1970-90|
|Squacco Heron||Ardeola ralloides||SPEC 3 Vulnerable||Large decline 1970-90|
|Purple Heron||Ardea purpurea||SPEC 3 Vulnerable||Large decline 1970-90|
|Glossy Ibis||Plegadis falcinellus||SPEC 3 Declining||Moderate decline 1970-90|
|Spoonbill||Platalea leucorodia||SPEC 2 Endangered|| Large decline 1970-90,|
|Greater Flamingo||Phoenicopterus ruber||SPEC 3 Localized||Localized|
|Marbled Teal||Marmaronetta angustirostris||SPEC 1 Endangered|| Large decline 1970-90,|
|Red-crested Pochard||Netta rufina||SPEC 3 Declining||Moderate decline 1970-90|
|Ferruginous Duck||Aythya nyroca||SPEC 1 Vulnerable||Large decline 1970-90|
|White-headed Duck||Oxyura leucocephala||SPEC 1 Endangered||<250 pairs|
|Pallid Harrier||Circus macrourus||SPEC 3 Endangered|| Large decline 1970-90,|
|Lesser Kestrel||Falco naumanni||SPEC 1 Vulnerable||Large decline 1970-90|
|Crane||Grus grus||SPEC 3 Vulnerable||Large decline 1970-90|
|Little Bustard||Tetrax tetrax||SPEC 2 Vulnerable||Large decline 1970-90|
|Great Bustard||Otis tarda||SPEC 1 Declining||Moderate decline 1970-90|
|Collared Pratincole||Glareola pratincola||SPEC 3 Endangered|| Large decline 1970-90,|
|Kentish Plover||Charadrius alexandrinus||SPEC 3 Declining||Moderate decline 1970-90|
|Greater Sand Plover||Charadrius leschenaultii||SPEC 3 Endangered||<250 pairs|
|Spur-winged Plover||Vanellus spinosus||SPEC 3 Endangered|| Large decline 1970-90,|
|Gull-billed tern||Gelochelidon nilotica||SPEC 3 Endangered|| Large decline 1970-90,|
|Little Tern||Sterna albifrons||SPEC 3 Declining||Moderate decline 1970-90|
This unique ecoregion with its salt formations is one of the centers of endemism of the rich Anatolian flora. There are 12 vascular plant taxa endemic to Tuz Lake itself. Among the better-represented families, Chenopodiaceae has about 35 species, including 6 endemic species and 3 monotypic genera. The Plumbaginaceae family has 14 species, of which 3 are endemic. Other endemic species are Gladiolus halophilus, Acanthalimon halophilum, Ferula halophila, Asparagus lyconicus, Allium vuralii, Verbascum pyroliforme, Salvia halophila, Salsola stenoptera, Kalidiopsis wagenitzii, Limonium iconicum, L. anatolicum, L. tamaricoides, Hypericum salsugineum, Onosma halophilum, and Taraxacum mirabile.
Kalidiopsis wagenitzii is one of the most important endemic species here, with a restricted distribution. It is found within the Halocnemum strobilaceum community between Eskil and Yenikent.
Mammal species known to occur in the salt steppes are Allactaga williamsi, (Spermophilus xanthoprymnus), golden hamster (Mesocricetus brandtii), badger (Meles meles) and marble polecat (Vormela peregusna), the latter considered vulnerable by the IUCN. The gray wolf (Canis lupus) is suspected to occur in the Tuz Lake basin. Significant reptiles known to occur in the area are Agama stellio, Mabuya aurata, Typlops vermicularis, Coluber najadum, and C. numnifer.
Larks are among the more typical birds of the steppe habitats, and six species are known to occur. Of greatest interest is the local subspecies Asian short-toed lark (Calandrella cheleensis ssp. niethammeri), which is restricted to the barren fringes of salt and soda lakes in the central plateau. The region is also of particular conservation importance for its small populations of great bustard (Otis tarda) and little bustard (Tetrax tetrax), the latter representing Turkey's only known population of this species. Both of these species are considered to be globally threatened.
This region contains 10 Important Bird Areas (IBAs), all of which are wetlands, including: Seyfe Lake, Hirfanl? Reservoir, Kulu Lake, Eregli Marshes, Karap?nar Plain, Esmekaya Marsh, Hotam?s Marshes, Bolluk Lake, Tersakan Lake and Lake Tuz. These IBAs are important for their populations of breeding birds as well as for the waterbirds that winter or migrate through here. In winter, the region supports significant numbers of white-fronted geese (Anser albifrons) and ruddy shelduck (Tadorna ferruginea).
A selected list of birds of conservation interest that occur in IBAs is presented in Table 1.
In 2001, Tuz Lake was declared a Specially Protected Area (SPA), including all of the lake surface and surrounding water beds and some of the important neighboring steppic areas. Turkey’s Authority for Specially Protected Areas (ASPA) is working on a project to decrease the amount of polluting agents entering this area, although it is unclear if it will be sufficient for natural resource management and conservation purposes.
Although the salt marshes here do not support plant species preferred by livestock, much of the area is nonetheless overgrazed. In particular, the Artemisia fragrans steppe at the edges of the salt steppe is highly degraded for this reason.
Types and Severity of Threats
Disruption of the natural hydrological regimes and over-consumption of freshwater resources pose the principal threats to the wetlands, salt lakes and freshwater bodies of the area. In spite of the arid and saline conditions that prevail, irrigation schemes have succeeded in using water from the streams that feed Tuz Lake and other scattered freshwater resources to convert some of the salty steppes to agricultural fields. This impacts the biodiversity both directly, through the conversion of valuable salt steppe habitat to monocultural crop fields, and indirectly through the diversion of scarce freshwater resources away from the natural vegetation. It also leads to a decrease in the overall freshwater content of the lakes, wetlands and streams.
One example of the potential threats from agricultural conversion is found in the attempt that is underway to initiate a development project in the Konya Basin by converting 240,000 ha into arable land for sugar beet production. The most destructive aspect of the project would involve the diversion of 15% of the water in the Göksu River and Delta to the Konya Plain.
Another example is provided by the E?mekaya Marshes, which have had conservation status as a Permanent Wildlife Reserve since 1994; the area also has a Significant Archeological Site. These marshes represent an important wetland in this ecoregion since they host one of the few freshwater bodies within the larger salt basin. However, although hunting is prohibited, other activities such as reed harvesting and irrigation are not controlled. In addition, the State Hydraulic Works (SHW) agency has plans to drain the site for agricultural production and to construct a reservoir at the northern end of the lake to irrigate the cropland.
Justification of Ecoregion Delineation
The ecoregion consists of the central Anatolian non-tree steppe described by Guidotti et al.
Additional information on this ecoregion
- For a shorter summary of this entry, see the WWF WildWorld profile of this ecoregion.
- To see the species that live in this ecoregion, including images and threat levels, see the WWF Wildfinder description of this ecoregion.
- World Wildlife Fund Homepage
- Avgan, B. and G. Eken. 1999. Mammals, reptiles, amphibians and endemic fishes of the Konya Closed Basin. Biodiversity Program Report No.11. Do?al Hayat? Koruma Derne?i. ?stanbul, Turkey.
- Birand,. H. 1960. Erste Ergebniesse der Vegetations-Untersuchungen in der zentralanatolischen Steppe. I, Halophytengessellschaften des Tusgölü. Bot. Jahrb. 79: 254-296.
- Boulos, L., A.G. Miller and R.R. Mill. 1994. South West Asia and the Middle East. Pages 293-349 in S. D. Davis, V.H. Heywood and A.C. Hamilton, editors. Centers of Plant Diversity. Information Press, Oxford, England. ISBN: 283170197X
- Eken, G. and G. Magnin. 1999. A preliminary biodiversity atlas of the Konya Basin, Central Turkey. Biodiversity Program Report No. 13. Do?al Hayat? Koruma Derne?i. ?stanbul, Turkey.
- Geldiay and Bal?k. 1998. Türkiye Tatl?su Bal?klar?. Ege Üniversitesi Fen Fakültesi Kitaplar Serisi. ?zmir, Turkey.
- Guidotti, G., P. Regato, and S. Jimenez-Caballero. 1986. The major forest types in the Mediterranean. World Wildlife Fund, Rome, Italy.
- IUCN. 2001. The 2000 IUCN red list of threatened species. IUCN, Gland, Switzerland and Cambridge, United Kingdom. ISBN: 2831705657
- Magnin, G. and M. Yarar. 1997. Important bird areas in Turkey. Do?al Hayat? Koruma Derne?i. ?stanbul, Turkey. ISBN: 9759608170
- Tucker, G.M. and M. F. Heath. 1994. Birds in Europe: their conservation status. BirdLife International (BirdLife Conservation Series no. 3), Cambridge, United Kingdom. ISBN: 0946888299
- Vural, M., T. Ekim, H. Duman, Z. Aytaç, and N. Ad?güzel. 1999. Vegetation and flora of the Konya Closed Basin. Biodiversity Programme Report No 12. Do?al Hayat? Koruma Derne?i-Gazi Universitesi, ?stanbul, Turkey.
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