Boundaries

This ecoregion includes essentially the upper sections of the Tigris and Euphrates rivers and their tributaries, with adjacent drainages in Iran that flow into the northern Gulf and other neighboring internal basins, and the Quwaiq River basin in Syria. It is bounded by the Orontes [437], Southern Anatolia [432], and Lower Tigris & Euprates [441] ecoregions to the west; northern Anatolia [430] and Western Transcaucasia [433] ecoregions to the north; Lake Van [444], Orumiyeh [445], Caspian Highlands [446], Namak [447], Esfahan [449], and Kavir & Lut Deserts [448] to the east; and Persian (= Arabian Gulf) and Northern Hormuz Drainages [451] to the south.

Topography

The topography of the Upper Tigris and Euphrates is characterized by the Zagros Mountains in the south that extend to 4548 m, the mountains of Kurdistan and their intervening valleys, and low-lying coastal plains at the head of the Gulf in Iran.

Freshwater habitats

The ecoregion comprises the upper reaches of large rivers such as the Tigris and Euphrates. There are occasional smaller lakes, but no extensive marsh/lake habitats like those found in the Lower Tigris & Euphrates ecoregion [441]. In the upper reaches on the plateau of Iran, springs and qanats are important habitats.

Terrestrial habitats

The terrestrial habitats are characterized by deciduous and conifer sclerophyllus-broadleaf forests in the northwest, montane steppe in the northeast, stone desert in the south near the coast, and steppe further inland. The landscape is mountainous with valleys of various sizes. It is heavily deforested at lower elevations; however, some original pistachio-almond and oak forests remain, but these are often sparsely vegetated. Dry farming occurs at higher elevations and in the north, as well as some tree crops. There are also patches of irrigated farming in the south.

Description of endemic fishes

Nearly a third of the species in the ecoregion are endemic, most of which occur in the genera Aphanius, Glyptothorax, Cobitis, Orthrias, and Schistura. Iranocypris is a monotypic genus endemic to this ecoregion.

Other noteworthy fishes

The ecoregion includes two blind cave fish, Iran cave barb (Iranocypris typhlops) and blind loach (Paracobitis smithi), recorded from Iran at a single locality and listed as Vulnerable in the IUCN Red List.

Justification for delineation

This ecoregion contains mostly riverine fauna comprising species shared with the Lower Tigris & Euphrates ecoregion [441], but with many endemics not found in these lowlands. The saline Sabkhat al-Jabbul Nature Reserve in Syria is a Ramsar site, as are the salt lakes Neyriz (and Kamjan marshes), Parishan, and Dasht-e Arjan in southern Iran.

Level of taxonomic exploration

Fair