Location and General Description
The Zagros Mountains forest steppe ecoregion is located primarily in Iran, ranging northwest to southeast and roughly paralleling the country's western border. It occurs along what Zohary (1973) terms the Zagros-Makran mountain arch, starting in the north around the Diyala River, near the Iraqi-Turkish border, passing through parts of southern Azerbaijan, Iranian Kurdistan and Faristan, and extending to Makran in southeastern Iran. In the northern and middle parts of the range, the mountain ridges are interrupted by deep valleys and other lowlands formed by waterways and faults. Prominent peaks include the Kabir Kuh in Luristan and the Kuh-e-Dinar (4,276m) in the Bakhtiari Mountains. Further to the southeast the mountain system continues into the districts of Fars, Laristan and Makran. Here the terrain is mostly comprised of lowlands and a plateau, interrupted by isolated mountains such as the Shiraz range, and with occurrences of large flats and salt marshes. A number of seasonal and permanent rivers flow through the area into the Gulf of Oman or the Lake of Jaz Murian (Zohary 1973).
The forest and steppe forest areas of the Zagros Mountain range have a semi-arid temperate climate, with annual precipitation ranging from 400 m to 800 mm, falling mostly in winter and spring. Winters are severe, with winter minima often below –25 degrees C, and extreme summer aridity also prevails (Anderson 1999; Frey & Probst 1986).
As characterized by Zohary (1973), the Kurdo-Zagrosian steppe-forest consists mainly of deciduous, broad-leaved trees or shrubs with a dense ground cover of steppe vegetation. The dominant species are oak (Quercus spp.), pistachio (Pistacia spp.) and a few others. In the northern reaches of the mountain range, lower altitudes (400m to 500m) host communities dominated by Astragalus spp., Salvia spp., or others while higher up (700m to 800m) forests or forest remnants of Quercus brantii and/or Q. boissieri occur up to an altitude of about 1,700m. Above the timber line (1,900m to 2,000m) appears a relatively wide zone of sub-alpine vegetation (Zohary 1973).
Further south along the range, the forest becomes more impoverished and a richer steppe flora develops among the trees. Forest remnants consist primarily of Quercus persica and, up to an elevation of 2,400m, xerophilous forest of Quercus spp., hawthorn (Crataegus), almond (Prunus amygdalus), nettle tree (Celtis) and pear (Pyrus spp) predominates. Below 1,400m, the vegetation is steppic, with shrubs predominating.
The Zagros Mountains have traditionally supported a rich variety of animal life, including brown bear (Ursus arctos), the Asiatic black bear (U. thibetanus), eagles (Aquila spp.), wild goats (Capra aegrarus), sheep (Ovis orientalis), wolves (Canis lupus), leopard (Panthera pardus) and other wild cats (Humphreys & Kahrom 1995; IUCN 2001). Five taxa of lizards are endemic to the Zagros range and the contiguous mountains of Anatolia (Anderson 1999).
The lesser spotted eagle (Aquila pomarina) and the golden eagle (A. chrysaetos) breed in forested hills and mountain areas in northern and western Iran. Capra aegagrus, distinguished by its majestic curved horns, lives in the high rocks and mountain areas; the IUCN Red List classifies this species as vulnerable, with major threats being hunting and habitat loss due to grazing and timber activities (IUCN 2001). These trends probably also threaten the leopard, which prefers mountainous country, forests and wooded areas where it can feed on sheep, goats and other prey (Humphreys & Kahrom 1995); the endangered subspecies P. pardus ssp. saxicolor prefers coniferous forests (IUCN 2001). Ovis orientalis, also notable for its impressive horns, inhabits mountainous terrain, temperate forest, and a range of other ecosystems. Blandford’s fox (Vulpes cana), one of the rarest foxes in the world, occupies the mountainous areas of Kerman and Fars. The highly endangered Persian fallow deer (Dama dama ssp mesopotamica), formerly common in Iran, was believed extinct until the 1950’s when a small population was discovered in the western foothills of the Zagros Mountains (IUCN 2001).
Other species that have been recorded in the southwestern part of this region include jackal (C. aureus), fox (Vulpes vulpes), marten (martes foina), mongoose (Herpestes ichneumon), striped hyaena (Hyaena hyaena), jungle cat (Felis chaus) and wild pig (Sus scrofa) (UNEP 1989a). In areas of semi-arid steppe, typical avifauna includes rock partridges (Alectoris chukar and A. graeca), see-see partridge (Ammoperdix griseogularis), little bustard (Tetrax tetrax), houbara bustard (Chlamydotis undulata), black-bellied sandgrouse (Pterocles orientalis) and black vulture (Aegypius monachus) (UNEP 1989b).
It has been observed that the Zagros Mountain chain forms a corridor for the southward distribution of northern faunal elements (Anderson 1999). Zohary (1973) cites evidence that the Zagros range is the original source of some species that are also now found in some eastern Mediterranean mountains, such as Quercus libani and Q. boissieri. He notes that Iran has served as the center of origin for a vast number of species and genera, including Astragalus, Euphorbia, Acanthophyllum, Salvia, Heliotropium, and Centaurea.
In areas of the Zagros range where rainfed cultivation and grazing occur, the natural vegetation has been reduced to remnants of its former extent. Overgrazing has also led to changes in vegetation composition, resulting in the retreat of the original woodlands and a wider distribution of thorny shrubs and thorny dwarf-shrubs. Advanced degradation is visible even in densely forested areas of the Zagros Mountains and species that are better able to withstand grazing and pruning have crowded out original species, such as Carpinus spp. and Quercus spp., in many areas (Frey & Probst 1986).
Since the discovery of the small population of Dama dama ssp mesopotamica, reintroduction and captive breeding projects have been initiated in northwestern Iran and several other countries. However, by 1988, the last wild population was verging on extinction (IUCN 2001).
There are a number of protected areas in the Zagros Mountains region. The Arjan Protected Area and Biosphere Reserve covers approximately 65,750 ha on the southwest flanks of the mountains. This reserve ranges in altitude from 825m to 3,219m and hosts a range of habitats and mammal species. Scientific and research activities have included extensive ecological studies and annual bird censuses (UNEP 1989a).
The Mooteh Protected Area is located on the eastern side of the Zagros Mountains, about 100 km south of Qom in the northern Esfahan Province. Covering 200,000 ha and ranging from 1,572m to 3,264m in altitude, it encompasses arid montane and steppe vegetation and is an important protected areas for larger mammals and avifauna (UNEP 1989b).
Types and Severity of Threats
Agricultural cultivation and overgrazing have contributed greatly to the reduction in areas of natural vegetation and continue to pose significant threats.
Justification of Ecoregion Delineation
Ecoregion boundaries correspond with the actual and supposed climax areas of two zones as classified by Zohary’s geobotanical map of the Middle East (1973): the xerophilous deciduous steppe forest of Quercetea brantii, and the contiguous (westernmost) reaches of actual and supposed climax area of Pistacia-Amygdalus steppe forest.
Anderson, S. C. 1999. The lizards of Iran. Society for the Study of Amphibians and Reptiles. St. Louis, Missouri, USA.
Frey, W. and W. Probst. 1986. A synopsis of the vegetation in Iran. Pages 9-43 in H. Kurschner, editor. Contribution to the vegetation of Southwest Asia.
Humphreys, P.N. and E. Kahrom. 1995. The lion and the gazelle. Comma International Biological Systems, Gwent, United Kingdom.
IUCN. 2001. The 2000 IUCN Red List of Threatened Species. IUCN, Gland, Switzerland and Cambridge, United Kingdom.
UNEP-WCMC. 1989a. Islamic Republic of Iran: Arjan Protected Area and Biosphere Reserve. Protected Areas Database on UNEP-WCMC web pages (http://www.unep-wcmc.org/protected_areas/data/sample/1653v.htm), visited October 23, 2001.
UNEP-WCMC. 1989b. Islamic Republic of Iran: Mooteh Protected Area. Protected Areas Database on UNEP-WCMC web pages (http://www.unep-wcmc.org/protected_areas/data/sample/1653v.htm), visited October 23, 2001.
Zohary, M. 1973. Geobotanical foundations of the Middle East: Vol.1, Gustav Fischer Verlag, Stuttgart, Germany.
Prepared by: Julie Bourns
Reviewed by: In process