Effect of physiographical factors on qualitative and quantitative characteristics of Rhus coriaria L. natural stands in Arasbaran region

Sumac (Rhus coriaria L.) has been naturally spread in Arasbaran forest (especially Horand region) and a remarkable amount of its fruits are exploited traditionally every year. This research tried to recognizing the habitat requirements of Rhus coriaria and the most important effective factors on its distribution. For this purpose, 36 circular samples (100 m2) in north, east and west aspects (each, 12 samples) were selected using 100 × 100 m grid by systematic sample method in natural sumac stands. The results showed that DBH, main collar diameter, height, crown diameter and crown cover means in the north aspect were significantly more than those of other aspects. Rhus coriaria included about 98% of individuals recorded in the samples. Seed origin individual’s percentage of sumac in North aspect was significantly more than east and west aspect. Slope and altitude have significant effects on quantitative and vegetative characteristics of Rhus coriaria but they don’t have any effects on origin and integrity. The average fruit weight per tree in the north aspect was significantly more than those of other aspects. Generally the results showed that northern aspect, class of height above sea level 1000-1200 m and class of slope 40-60% present better conditions to Rhus coriaria growth.