Effect of Altitude and Growing Season on Some Physiological Properties of Leaf from Persian Oak (Quercus brantii) in Zagros Forest (Case study: Ilam)

Abstract Understanding in variation in tree leaf related to altitude and climate change define the plant adaptation. These variations will predict their respond to the future changes. According to the vast distribution of Persian oak (Quercus brantii) trees in Zagros forest, the study of structural changes and the recognition the Persian oak ecological needs is crucial for their conservation and management. The aim of present study was to study the changes in the physiological traits of Persian oak leaves due to low changes in altitude as well as growing seasons (spring and autumn) in Gachan, Ilam province. For this purpose, leaf physiological traits were investigated in three oak populations at altitudes of 1640 m, 1821 m, and 1900 m a.s.l along an altitudinal slope. In each population, five seed-originated trees with almost similar diameter and characteristics were selected. The sampled leaves were collected from outer and middle part of tree crown. The leaves were mixed together and then about 20 were randomly sampled for physiological study. According to the results, highest values of EC, Chlorophyll a, and total were 31.81%, 15.57(Mg/g FW), and 20.72 (Mg/g FW) in autumn and at low altitude. Highest amount of RWC and Proxidase were determined in spring and low altitude as 30.15% and 0.17 (μmol-1 min-1 g-1 FW-1), while highest amount of pH, carbohydrate and Catalase were respectively: 5.12, 0.09 (μg/g FW), and 0.70 (μmol-1 min-1 g-1 FW-1) in autumn and high altitude. Additionally, highest amount of proline was determined in spring and middle altitude as 0.34 (μg/g FW). In general, the results of this study indicate that the physiological traits of Persian oak leaves are affected by less change in altitude as well as different growing seasons.