A study of some structural attributes of Yew (Taxus baccata L.) in Gazoo forest, Mazandaran Province

In this study, 50 hectare of mixed yew stand was structurally investigated across Gazoo forest, a study area between 1100-1300 m a.s.l located 50 km from Zirab town in Mazandaran province. All yew individuals above 7.5 cm D.B.H were full calipered by measuring their height and DBH. A transect of 20 ×100 m was selected to study the stand vertical structure. Within the transect, DBH, height, crown diameter and distance from origin of each tree were measured. The diameter distribution curve of yew stand resembled an even-aged stand, which was yet due to a long-term decrease of regeneration which resulted in absence of young yew individuals. The stand structure was two-story (three-story in thinning area), with Fagus orientalis and Carpinus betulus trees covering the overstory. Maximum height and DBH of yew trees were 30 and 2 m, respectively. Volume of standing tree was 593 m3 ha-1, which accounted for 17% of the total volume percentage within the stand