برررسي صنوبر كاريهاي انجام شده دو رويشگاه تنيان و حفظ آباد در استان گيلان

Investigating of structure differences between popolus afforestation in two habitats in Gilan

In recent decades , Population growth , wood demand , reduction of forest harvesting in north of Iran and necessity of providing it from afforestation have increased popolus agronomy. then we should try to know its structure and suitable habitat. In this research , we compared properties of two popolus blocks and its structure in Gilanʹs forests. Sampling was done at the 500 m2 plots with likelihood-systematic method. t-test and regression were used for analysis with help of SPSS and Excle software. Results show that Hefzabad was more uniform than Tenyan and density of trees and volum in hectare was lower in Tanyan. Also , the hieght growth at same diameter in Hefzabad was more, and corralation between diameter and hieght in Tenyan was more than Hefzabad. in addition , there are significant different in diametere frequency and curve of tree frequency - diametere classes have lower skewness in Tenyan. Maximum of tree number in each diametere class in Tenyan and Hefzabad were 15 and 20 cm ,respectivly. Meanwhile, study of diversity show that both of tow cases study were alnus natural habitat .