Effects of Altitude on the Growth Characteristics of Lebanon Oak (Quercus libani Olive.) in Kurdistan Province

The present investigation was aimed to study the qualitative and quantitative characteristics of Lebanon Oak (Quercus libani Olive.) in Marivan city-kordistan. To investigate the effect of altitude on the qualitative and quantitative characteristics of Lebanon Oak, 108 circular plots of 1000 m2 on three elevation classes of 1400-1600, 1600-1800 and 1800-2000 m were designated. Within each plot, the desired characteristics include: trees diameter at the breast height, height of trees, basal area, crown coverage, quality of trunks, crown symmetry and the status of regeneration were studied. Results showed that DBH quantitative and qualitative characteristics of Lebanon oak trees within the altitude of 1600-1800 m above sea level were significantly different compared with trees located in the altitude of 1400-1600 m. The highest mean diameter at breast height (20.77 cm), trees height (6 meters), basal area (3.75 square meters per hectare) were located in the altitudes of 1600-1800 meters above sea level. The average number of trees per hectare and average crown coverage were 92 and 12% in this altitude, respectively. 37.9% of the trees had a symmetrical crown. Also, about 48% and 52% of the tree regeneration were with the coppice and seed origin in this altitude, respectively. The results also showed that no significantly difference was found between the elevation range for 1600-1800 and 1800-2000 and the suitable elevation range of Lebanon Oak trees regarding to the quantitative and qualitative characteristics was 1800-1600 m.