Effect of physiographic factors on quantitative characteristics of cypress (Juniperus excelsa M. Bieb) trees (case study: Spiro cypress habitat–Damghan)

This study was carried out to study the habitat characteristics of Persian juniper trees due to the topographical factors and site exposure in Spiro forest habitat, located at Damghan County. Inventory done by systematic method (Net dimensions: 300×400m). Trees number and diameter at breast height in 10 R area sample plots were taken. Then, the topographic factors effects on some of the growth variables of Persian juniper stands such as basal area and number per hectare were evaluated using stepwise regression model. The results showed that three indices of aspect, site exposure and topographic wetness had a positive and significant correlation with the number of hectares of trees. Also, elevation from the sea level, site exposure and roughness had a positive and significant correlation with trees basal area variable per hectare. According to the results, the most correlation between cypress quantitative characteristics, including number per hectare and its basal area, was obtained by topographic factor of site exposure.