Golestan is situated at the eastern end of the Alborz Mountains between the cities of Gonbad-e Qaboos and Bojnurd, and spans the divide from the humid lowlands of the Caspian region to the semi-arid interior of the central plateau. The principal habitats consist of lowland deciduous forest, lowland secondary scrub and meadows, semi-arid steppe, open Juniperus woodland and scrub, upland meadows, springs and streams, and cliffs and crags. Mountains in the south-west third of the reserve from the lowest to the highest elevations (380-2,410 m) are covered with largely pristine climax forest. Dominant trees below 1,800 m include Quercus castanaefolia, Parrotia, Carpinus, Zelkova, Alnus, Fraxinus and Tilia. Higher up, Quercus macranthera, Sorbus, Acer and Juniperus are common. The humid influence of the Caspian dwindles to the east, with forest giving way to scrub and then lush steppe. This montane steppe is characterized by Artemisia, spiny vegetation (predominantly Astragalus, Acantholimon and Cousinia), grass, open stands of Juniperus and copses of Acer. Inter-tribal conflicts which prevailed prior to 1913 virtually precluded any human habitation-even grazing of stock was risky-and for this reason the site was relatively undisturbed. The Asian highway winds north and east through the reserve and provides easy access. Land ownership is public.
See box for key species. There is a very diverse breeding bird fauna with virtually all the species characteristic of Caspian forest and upper shrub and Juniperus zones as well as many species characteristic of the upland steppes of north-east Iran. It is one of the few known breeding areas for Tetrax tetrax and Dryocopus martius in Iran, and is especially rich in birds of prey. Notable breeding species not listed below include Hieraaetus pennatus, H. fasciatus, Phasianus colchicus, Melanocorypha bimaculata, Phoenicurus erythronotus, Sylvia hortensis, Phylloscopus trochiloides nitidus, Ficedula semitorquata, F. parva, Lanius isabellinus, Emberiza buchanani and E. bruniceps. At least 151 species have been recorded.
Non-bird biodiversity: Mammals: the mammal fauna is extremely rich and diverse, including Ovis ammon (rare), Capra hircus aegagrus (rare), Gazella subgutturosa (rare), Lynx lynx (rare), Canis lupus (V) and Ursus arctos (rare). Panthera tigris virgata was last reliably recorded in Iran in this area in about 1963.
BirdLife International (2019) Important Bird Areas factsheet: Golestan. Downloaded from http://www.birdlife.org on 25/06/2019.