Exploring the effect of habitat altitude on leaf morphology of Iranian hornbeam (Carpinus betulus L.) in Shast Kalateh forests in Gorgan

The present experiment investigated Iranian hornbeam (Carpinus betulus L.) in 3 separate altitudes namely 300, 450 and 860 m above the sea level in Shast-Kalateh forests of Gorgan. Three standing trees were randomly selected in each altitude during the summer and 40 leaves were collected and dried from the middle part of the crown in each stand (10 leaves from each geographical directions). The morphological parameters of the leaves including: petiole length, leaf length, leaf wide, nerve number (right and left), teeth number (right and left), and leaf area were measured. Using statistical analyses, the relations between the measured leaf parameters in three altitude populations were investigated. The results indicated that leaf traits changed with an increase in the altitude. This trend in some traits (i.e. petiole length, leaf length, and teeth number) was a decreasing one and in some other traits (i.e. leaf width) an increasing one. It was also observed that the petiole length and leaf area were more significantly affected in comparison to the other leaf traits in the populations which were analyzed. Some leaf traits including leaf width and teeth number demonstrated a significant relation with the changes in the temperature and the amount of rain.