Zagros Mountains forest steppe

Category: Forest Biomes.

Geographic Location: Middle East.

Summary: An ancient source of many modern foods, which is now an ecosystem rich in faunal diversity, this forest steppe region is at risk from human action and global warming.

The Zagros Mountains is the largest mountain range in Iran, extending roughly 900 miles (1,500 kilometers) from the northwest to the southeast and paralleling the border with Iraq to its west. It ends in the south, in rocky cliffs by the coasts of the Persian Gulf and the Gulf of Oman. Comprised mainly of shale and limestone, the range has numerous folds and ridges created by the pressure between the Arabian and Eurasian tectonic plates.

This ecoregion is marked by many peaks, some of which reach elevations of more than 10,000 feet (3,000 meters). Iran’s main oil fields are located in the southwestern foothills of the Zagros. Agricultural development and livestock overgrazing pose ongoing threats to this ecoregion, as does petroleum extraction.

Deciduous broadleaf forests, dominated by Persian oak, and endangered animals such as the wild goat and the Persian leopard are characteristic of the forest steppe biome here. The mountain forest steppe ecoregion features numerous deep and narrow valleys eroded by small rivers that separate a series of parallel mountain ridges, primarily in the northern and central portions of the range. Its southern face is marked by a steep descent, leading into Khuzestan Province in southwestern Iran near the Tigris-Euphrates river delta. The eastern face is marked by a smoother transition into the Iranic Plateau. The three highest peaks of the Zagros—Dena, Oshtoran Kuh, and Zard Kuh—reach elevations around 14,000 feet (4,000 meters) and are permanently covered in snow.

This ecoregion features numerous waterfalls, pools, and lakes. Many large rivers, including the Karun, Dez, and Kharkeh, originate here, draining either southward into the Persian Gulf or north to the Caspian Sea. Snowmelt feeds the twin Gahar Lakes, located more than 8,300 feet (2,500 meters) high in the mountains near several deep canyons, including the Bactiara River Canyon, the Sezar River Gorges, and the Karun River Canyon. There are also numerous caves, notably Ali Sadr, a calcite crystal water cave near the city of Hamadan, which contains a clear lake that extends for 9 miles (14 kilometers).

The Zagros Mountains Forest Steppe ecoregion experiences a semiarid temperate climate. Annual precipitation ranges from 15 to 30 inches (40 to 80 centimeters), with rain falling primarily in the winter and spring months. The summer and fall months are quite dry. The winters are extremely cold, with temperatures dipping below minus 13 degrees F (minus 25 degrees C).

Flora and Fauna

The boundaries of this biodiverse ecoregion correspond with two biologically mature steppe forest communities: a xerophilous, or low-moisture, deciduous highland forest covering the western slopes, dominated by Persian oak (Quercus brantii); and a lowland forest dominated by cashew (Pistacia) and almond (Prunus amygdalus) scrub. Other trees and shrubs include Syrian pear (Pyrus syriaca), Persian walnut (Juglans regia), hornbeam (Carpinus), hawthorn (Crataegus), hackberry (Celtis), olive (Olea), and plane (Plantanus). The genetic predecessors of many familiar foods—including wheat, barley, lentils, almonds, apricots, plums, pomegranates, and grapes—can be found growing wild throughout this region.

The ecoregion supports a wide variety of invertebrate species. Mammals recorded in this area include the brown bear (Ursus arctos), Asiatic black bear (U. thibetanus), Syrian jackal (Canis aureus syriacus), fox (Vulpes vulpes), marten (Martes foina), sheep (Ovis orientalis), wolf (Canis lupus), mouselike hamster (Calomyscus bailwardi), mongoose (Herpestes ichneumon), jungle cat (Felis chaus), and wild pig (Sus scrofa). The striped hyena (Hyaena hyaena), also found here, is listed as threatened.

Bird species include the lesser spotted eagle (Aquila pomarina), golden eagle (Aquila chrysaetos), rock partridge (Alectoris chukar and A. graeca), ase-see partridge (Ammoperdix griseogularis), little bustard (Tetrax tetrax), houbara bustard (Chlamydotis undulata), black-bellied sandgrouse (Pterocles orientalis), and black vulture (Aegypius monachus). There are also five taxa of endemic lizards.

The wild goat (Capra aegagrus), known for its large, curved horns, is classified as a vulnerable species on the International Union for Conservation of Nature (IUCN) Red List, because of hunting and habitat loss caused by timber production. The Persian leopard (Panthera pardus) is listed as endangered by IUCN, because of over-hunting for supplying the fur trade and in defense of livestock. One of the world’s rarest foxes, Blandford’s fox (Vulpes cana), also lives in the Zagros Mountains Forest Steppe ecoregion.

Believed to have gone extinct, the Persian fallow-deer (Dama mesopotamica) was rediscovered here in 1956. Assessments by the IUCN have found that the total population of Persian fallow-deer rose to more than 250 mature individuals by 2020. The species was listed as endangered.

Human Impact

The Zagros mountains forest steppe is threatened primarily by human activity. The spread of agriculture and overgrazing livestock have destroyed much of the region’s natural flora. Oil development in the southwest remains a cause of concern for conservationists. In many areas, populations of native tree species such as oak and hornbeam have been decimated. Climate change has already been cited for increased frequency of droughts and dust storms in the region, exacerbating the trend of desertification.

The establishment of several protected areas supports a wide range of vertebral species in various habitats. The Arjan Protected Area and Biosphere Reserve spreads for more than 250 square miles (650 square kilometers) across the southwestern face of the Zagros range. Lake Parishan and Dasht-e-Arjan are Wetlands of International Importance (Ramsar) and provide habitat for many bird species. Bamou National Park provides habitat for a variety of mammals, some vulnerable, including the Bezoar goat, caracal, Blanford’s fox, Indian crested porcupine, and several bat species.

Bibliography

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