An investigation on the Fraxinus excelsior plantation under different situations of physiography (Case Study: Dooleychal, Masouleh, Guilan province)

The aim of this research was to investigate the effect of physiographic effects (slope, aspect and altitude) on the quantitative and qualitative characteristics of Fraxinus excelsior plantation in Dooleychal in Masouleh, Guilan province. For this purpose, 100 0.2 ha circular sample plots were established as systematic random in an area about 400 ha. Within each sample plots, the physiographic factors (slope, aspect and altitude m a.s.l), quantitative characteristics (collar diameter and total height) and qualitative characteristics (vitality and multi-branching) were measured and recorded. The results of analysis of variance showed that there is a significant difference between the mean diameter of the collar and the total height of ash tree in different directions. Also, the results showed that there was no significant difference between the diameter of the collar in different slopes, while there was a significant difference between the height of the ash tree in different slopes. The results of t-test showed that there was a significant difference between the collar diameter at different altitudes, while there was no significant difference between the height of the ash tree at different altitudes. The study of the effect of aspect on the qualitative characteristics showed that highest level of vitality and multi-branching were observed on the north- and south-facing slopes, respectively. The study of slope effect on qualitative characteristics showed that highest level of vitality and multi-branching were in the range of 0-20%. Investigation of the effect of altitude m a.s.l on qualitative characteristics showed that the highest level of vitality and multi-branching were at 1700-1.900 meters.