study of carpinus betulus dieback distribution using topographic factors

the expanding phenomenon of dieback is caused by the reaction of trees against the harmful biotic and a biotic factor that lead to dying of shoots and branches of trees from upper crown to lower crown. this phenomenon spreads throughout the leaves and branches and all parts of the plant and may finally lead to the death of the plant. this study aimed to identify species dieback especially carpinus betulus and to study the spread of dieback in this species using topography factors in series one of shastkalate forest. in the studied area, a statistical network with dimensions of 600*800 m was randomly and systematically designed (network of plots) and cluster sampling with six trees was applied (in every plot). topographical factors (altitude, slope direction and percentage) in each plot were taken. analyzing the data indicated that 28% of the total stands suffer from different degrees of dieback among which 22% belong to the carpinus betulus species. the percentage of dieback stands of this species in different classes of height had no meaningful difference, but it was more in western slope and gradient of less than 20%.