Effect of the oak decline on the secondary compositions in oak leaves Case study: Zagros forest- Lorestan

In recent years, Querqus trees especially those which are located in the Lorestan province, in the Central Zagros forests, have faced to the Oak decline phenomenon. Different natural and unnatural factors can make this phenomenon to occur. Quercus brantii, the dominant species of the Lorestan forests, is suffered from this phenomenon and it has been degraded in wide range. Quercus brantii contain different type of secondary compositions. Secondary compositions in the leaves react as a defensive mechanism against stress maker conditions. In present study, to investigate the effect of oak decline on the secondary compositions such as total tannin, insoluble suger, principal soluble suger, condensed tannin and antioxidant of the leaves of Quercus branti, some sample of the leaves from affected trees in the Lorestan forests were gathered. After different tests on the leaves of Quercus brantii, the analysis of the acquired data was conducted using the factorial experiment and independent t-test. The rate of total tannin, insoluble suger, principal soluble suger and condensed tannin in the affected tress in the regions of Miankooh, Maleshaban and Abolvafa had a significant difference with the healthy trees but the rate of antioxidant did not show a significant difference. Moreover, the rate of condensed tannin in the regions of Miankooh and Abolvafa were significantly greater than the other areas. Stressful conditions such as oak decline, cause changes in the amount of secondary compounds in leaves. Studying these changes can help diagnosing and controlling the prevalence of stressful conditions.