Effect of Physiographic Factors on Mortality of Persian Oak in the Middle of Forests (Case study: Ilam)

This study aimed to determine the effect of physiographic factors (slope، aspect and altitude) on quantitative characteristics of Persian Oak (Quercus brantii Lindl) in forests of midlle Zagros. In this study in forests of the Abdanan city if Ilam province and regional functions area were approximately 150 ha، 134 sample plots of rectangular shape with dimensions 40 * 50 m to the systematic – random method in a network with dimensions 100 * 100 m using and species characteristics، dbh، crown diameter، heigh of trees and physiographic sample plot (slope، aspect and altitude) were recorded. Results showed that the effect of physiographic factors on dbh of trees was not significant. The aspect and altitude on the characteristics size canopy of tree، basal area per ha and number of ha has a significant impact. Among the physiographic factors aspect have a significant impact on trees height. This study can conserved areas that Oak species with quantitative characteristics better and special attention to areas that are being destroyed، to be effective.