Morphological Characteristics of Old Trees in Zagros Forests (A Case Study: Forests of Ilam province)

This study was conducted in oak forests of Ilam province in order to evaluate the morphological characteristics of old trees including diameter at breast height, trunk height, whole tree height, minimum and maximum crown diameter, crown health, crown vitality, crown symmetry, health and form of the trunk, Was investigated. Selection of old trees was performed based on the criteria of DBH and without plot sampling method. After forest survey the number of 60 old trees consists of 31 pistachio trees, 27 persian oak trees and two hackberry trees were identified. Results showed that wild pistachio had the highest average of DBH and Persian oak had the highest average of whole tree height and maximum of DBH and whole tree height. The old trees averages for DBH was 130 cm, trunk height 1.9 m, whole tree height 8.7 m, crown length 6.8 m, crown area 107 m2 and slenderness coefficient 7. 45% of old trees had healthy crown, 81% of trees had juicy crown, 87% had symmetrical crown, 31% had healthy trunk and 76% of them had unit trunks. The greatest percentage of unit trunks was belonged to oak tree species. The highest percentage of crown symmetry, health and vitality was belonged to pistachio. With regard to the favorable characteristics of old trees and the stability along their long life, using their seeds for producing resistance seedlings is an appropriate way to restoration of degraded parts of zagros forests.