The effect of dust particles on the wettability of some native plants in Zagros Mountains, Iran

In recent years, in addition to pollution from cars, factories and other polluting devices, the country of Iran has been the destination of dust that have entered from Iraq and Saudi Arabia and caused pollution of the climate. In this research, the wettability of some native plants in Zagros Mountains has been investigated experimentally by measuring the contact angle. Sampling of oak trees of Quercus brantii Lindl. species was carried out around Khorramabad city, Nozhian waterfall, Chegheni city, and recreation area of Shoorab forest park. Forty samples of oak leaves, red mulberries of Morus rubra L. species and white mulberries of Morus alba L. species were randomly selected and the contact angle of the water drop on them was measured using a contact angle goniometer and also separately measured by Image J software. Under the influence of the dust, it was observed that the contact angle of the leaf area was completely eliminated, but the contact angle of the abaxial leaf surface had not changed; this change in the contact angle seem to be due to the loss of acylic cyst of the oak leaf caused by the disruption of the photosynthesis operation. Oak trees absorb contaminants. This problem eliminates leaf pores and dry leaves. Also, results show that the oak leaves are hydrophobic and have good resistance to drought. However, the presence of a lot of dust causes water droplets to spread completely on the oak leaves, thus reducing watering to the roots. As a result, dust reduces the resistance and resilience of oak trees against drought. Present study is very important for protection and monitoring of forest health and prevention of the reduction of plant species diversity.