Effect of soil properties on Oak tree dieback (Quercus brantii Lindi.) and its ‎ecophysiological ‎responses to different degrees of dieback (case study: Dadabad in ‎Lorestan Province)‎

To investigate the relationship between some physical and chemical properties of soil and tree ecophysiological properties on dieback of Oak trees, 30 square sample plots with 2500 m2 area, in a random systematic grid (200×200) were selected. The percentage of dieback were measured in each sample plot and soil and leaves of trees were sampled. Some soil properties such as texture, electrical conductivity, acidity, bulk density, porosity, Carbon and organic matter and concentrations of Ca, Mg, N, P, K, Na were measured. Also, Peroxidase, Catalase and Ascorbate peroxidase enzymes, MDA, Proline, Chlorophyll a, b, total Chlorophyll, Carotenoid pigment and concentrations of Ca, Na, K, Mg, P and N in leaves were measured. Comparison of variable means showed that there is just significant difference in leaf nitrogen between different dieback classes. In general, the results of this study showed that the soil properties in our study area were not significantly affect on oak decline. On the other hand, the physiological capabilities of trees solely, cannot be the cause of their different dieback.