Comparing the quantitative attributes and the cross-section per hectare and species diversity in the forest masses of two managed and unmanaged regions (Case study of Nav Asalem forests)

ABSTRACT: In the present study, the quantitative variables of the number and cross-section per hectare of the forest masses and the species diversity in two managed and unmanaged regions in the series 3 of the Nav Asalem were studied and compared to each other. For the sake of sampling, the collection of statistics was carried out using random-systematic method with an unchanging network measuring 150*200 meters with 10-R circular plots. In each sample plot, the diameter and height of the trees and the percentage of the tree species was measured. After the collection of data, the information needed were restored in the Excel software and analyzed using the SPSS statistical application for testing the significance of the difference between the quantitative parameters and indices in the two regions through t -test and the diversity of tree species was examined using the Shannon-Weiner and Simpson methods. The results of this study showed that in terms of the number per hectare, there were 268 trees per hectare in the managed mass and 170 trees per hectare in the unmanaged mass while the average cross-section per hectare in the two managed masses stood at 39.8 m2 per hectare and 38.6 m2 per hectare in the unmanaged mass. Moreover, it was demonstrated through t-test that in terms of cross-section and number, there’s a significant relationship between the two masses while no significant difference was observed between the two managed and unmanaged masses.