Pistacia atlantica Desf. (Persian turpentine tree) is considered as one of the most important species of Zagros forests and plays a significant role in the economy of local exploiters. In this study, the resistance of this species to micro-dust has been evaluated. For this purpose, 40 potted seedlings were prepared and transferred to the study area. Seedlings were divided into two groups of n = 20 as micro-dust treatment and control. Seedlings were irrigated every three days and, in each irrigation, the leaves of control pots were washed with irrigation water to remove micro-dust, but in pots treated by dust, water was poured in pots only for irrigation of the seedlings. At first, leaf anatomical properties of this species were investigated by scanning electron microscope (SEM), and then, the effect of micro-dust on the anatomical properties of the leaves as well as some physiological activities of this species has been investigated. The results SEM examination showed that there are two types of glandular and solitary trichome on both abaxial and adaxial surfaces of the leaves. The epicuticular waxes were thin and flakes. According to the results, rare trichomes on the leaf surfaces and the waxy coverage had no significant impact on the deposition of micro-dust in P. atlantica. Meanwhile, on the adaxial surface of the leaves, there was more blocked stomatal aperture by micro-dust (31%) than on the abaxial surface of the leaves (7%). The amount of micro-dust deposited on the leaves of this species had no significant effect on the reduction of chlorophyll, photosynthesis and gas exchange as well as the content of the leaf proline. Regarding to the low susceptibility of P. atlantica to micro-dust phenomenon and on the other hand, its ecological and economical importance in the Zagros forests, the cultivation and the conservation of this species in that area are highly recommended.
