تأثیر ارتفاع از سطح دریا بر برخی ویژگی های کمی و کیفی درختان صنوبر دلتوئیدس

      In order to study the effect of altitude on some quantitative and qualitative characteristic of Populus deltoides in Mazandaran province, three sites were selected with elevations between 150 and 1200 m above sea level in Sari city. In each site, some tree traits such as diameter at breast height, total height, basal area, volume, form factor and qualitative variables including trunk health, crown shape and trunk form were measured and evaluated and quantitative and qualitative characteristics of trees in three sites were compared using one-way ANOVA and Kruskal Wallis tests. Results showed that the altitude had significant effects on qualitative and quantitative characteristics of Populus deltoides trees and trees in lower altitude ranges (150-300 m) had a higher diameter and volume growth than trees in higher altitudes. According to results, the highest diameter (27.83 cm), height (21.13 m), basal area (0.046 m2), volume (2.11 m3) and the highest number of trees with cylindrical trunks were observed in Mahdasht. Tress in Pahnekola had the highest form factor (0.99) and with symmetrical crowns. According to results of this study, it can be concluded that planting with Populus deltoides trees in lower altitude ranges can increase the qualitative and quantitative characteristics of such trees and provides a suitable approach for supplying wood for wood-based industries.