Effect of physiographical factors on tree species diversity (case study: Kandelat Forest Park)

In order to identify the diversity of tree species in relation to physiographic factors (elevation، aspect and slope)، the Kandelat Forest Park with an area of 614. 85 hectare was surveyed، where is located southeast of Rasht city. For this reason، maps of slope، aspect، elevation and dominant vegetation types were provided، using GIS technology. As a result، 18 homogeneous units were obtained by layering the mentioned maps. In each homogeneous unit، five sample plots، and totally 90 plots were randomly located. The trees at each plot were found and their diameter at breast height (dbh) was measured. Overall، 17 tree species belonging to 16 genera and 12 families were identified. Result revealed that aspect had significant effect on diversity and evenness of the tree species. Species diversity and evenness on south aspect were significantly more than the other aspects. In addition، elevation had significant effect on diversity and species diversity and richness were greater at high elevations. There was not significant effect of slope aspect on tree''s species diversity، richness and evenness.