Abstract

A wide area of Iran is covered by arid and semiarid regions. In this survey, flora of an area of the Miandasht Wildlife Refuge, out of the safe part, was studied. This region covers 84435 Ha, situated in the west of Khorassan province in Iran. The climate of the area according to de Martone system is semiarid. The mean annual precipitation is 275 mm and the altitude varies from 931 to 1021 m above sea level. Plants were collected from 2008 to 2011. A total of 256 taxa belonging to 152 genera and 35 families from Angiospermae and Gymnospermae were found. Asteraceae, Chenopodiaceae, Brassicaceae and Fabaceae were the greatest families, respectively. Geraniaceae, Ixioliriaceae, Orobanchaceae, Plantaginaceae, Primulaceae, Resedaceae and Rosaceae, each included one species. Based on Raunkiaer life form classification system, majority of the species (55.86%) were therophytes. Other life forms in descending order were hemicryptophytes (15.62%), chamaephytes (10.16%), phanerophytes (8.6%) and geophytes (9.38%). Chorologicaly, most of the species were Irano-Turanian. Flora of Miandasht Wildlife Refuge include 20 low risk species and 29 (11.6%) endemic of Iran species. 67 pasture species and 38 medicinal species were distinguished. Most of the species were invasive plants. They are established in this area because of overgrazing and natural disturbance.

Key words: Flora, Miandasht Wildlife Refuge, Iran endemic, life form, chorotype.