Boundaries

This ecoregion includes the upper rivers and tributaries of the Caspian Sea basin on the plateau of Iran (including the upper basin of the Safid River).  It is bounded on the north by the Kura-South Caspian Drainages [434] and a small section of the Turan Plain [450], to the south by the Kavir & Lut Deserts [448] and Lake Namak [447] ecoregions, and to the west by the Upper Tigris & Euphrates [442] and Orumiyeh [445] ecoregions.

Topography

The ecoregion lies on the western side of the Iranian plateau, and has altitudes reaching 5601 m at Damavand and 4819 m at Takht-e Suleiman along the Alborz Mountain range. Most of the smaller rivers have deep valleys. The Qezel Owzan and Shah rivers are also deeply incised in parts, but also have more open valleys and drain large steppe plains.

Freshwater habitats

The amount of freshwater vegetation in the ecoregion is poor. There is a lot of erosion and consequent siltation; for example, the dam at Manjil is dredged.

Terrestrial habitats

The ecoregion is predominantly semi-desert steppe on the plateau of Iran, exluding the Caspian lowland forests. Most vegetation is scrub, although there is some mixed forest at higher elevations. Dry farming and irrigated farming occurs, as well as tree crops.

Description of endemic fishes

There are no endemic species in this ecoregion. Mursa (Barbus mursa) is a near-endemic to this ecoregion and the Kura-South Caspian Drainages ecoregion [434].

Other noteworthy fishes

The dam at Manjil and other rivers have introduced taxa including pike-perch (Sander lucioperca), common whitefish (Coregonus lavaretus), silver carp (Hypophthalmichthys molitrix), rainbow trout (Oncorhynchus mykiss), and eastern mosquitofish (Gambusia holbrooki). Survival of first two taxa in the dam is unknown.

Justification for delineation

This ecoregion comprises a subset of the Kura-South Caspian Drainages ecoregion [434], but without migratory and semi-migratory species. 

Level of taxonomic exploration

Good