Impact of Oleo-Gum Resin Extraction Periodicity on Natural Regeneration of Wild Pistachio

In order to evaluate the impacts of oleo-gum resin extraction periodicity on natural regeneration of wild pistachio (Pistacia atlantica subsp. kurdica), three different forest areas in Kurdistan province, west of Iran, were selected based on difference extraction periodicities (regular periodicity, irregular periodicity and without periodicity). Then homogenous unit maps in GIS produced, and one unit with identical characteristic from any three different areas were selected. Sampling in the selected units was implemented on100 pistachio tress with diameter at breast height (DBH) more than 25 cm. On each tree, DBH, number of regeneration below and outside of its crown were recorded. Results showed that the amount of regeneration among the three forest areas was significantly different (p