Iranian Journal of Forest

Iranian Journal of Forest

Determination of stem form factor of white poplar (Populus alba L.) using a non-destructive sampling in the Chaharmahal and Bakhtiari province of Iran

Document Type : Research Paper

Authors
R Akhavan 1
F Ahmadloo 2
M Talebi 3
1 Associate Prof., Research Institute of Forests and Rangelands, Agricultural Research, Education and Extension Organization (AREEO), Tehran, I.R. Iran
2 Assistant Prof., Research Institute of Forests and Rangelands, Agricultural Research, Education and Extension Organization (AREEO), Tehran, I.R. Iran
3 Senior Research Expert, Research Division of Natural Resources, Chaharmahal and Bakhtiari Agricultural and Natural Resources Research and Education Center, AREEO, Shahrekord, I.R. Iran
10.22034/ijf.2025.497977.2030
Abstract
Introduction: Estimating the volume stock of poplar plantations plays an important role in understanding the current status and sustainable management of these resources in order to planning production and improve management decisions for the development of wood farming in the Chaharmahal and Bakhtiari province of Iran. The stem form factor is one of the most important characteristics for determining the exact volume of trees. The aim of this research is to determine the stem real form factor for white poplar (Populus alba L.) and compare it with the natural and artificial form factors.
Material and Methods: To conduct this research, initially, the major poplar plantation stands were identified in the province by field surveys. Then, in 10 different stands of poplar plantation with white poplar species, a total of 67 trees were selected using stratified random sampling method based on diameter classes from 10 to 30 cm. After selecting the sample trees, their diameter at breast height, 0.1 height and mid-height and total height, as well as the location of 2-m sections from the stem collar upward, along the stem, were determined and measured using a Leica D810 laser-based device, without tree felling. Then, the real volume of each tree stem was obtained from the sum of the volume of 2- m logs using the Smalian’s formula to be used in calculating various stem form factors. To check for a significant difference between the stem real form factor with the other two form factors (natural and artificial), a paired t-test was used.
Results: The results indicated that the real, natural and artificial stem form factors of white poplar in this province were 0.44, 0.47 and 0.39, respectively. Furthermore, the results of the paired t-test showed that there was a significant difference at the 99% confidence level between the form factors of artificial and natural with real. Also, based on the calculated slenderness coefficient, the studied poplar plantations were unstable in all diameter classes.
Conclusion: According to the results of this study, it can be concluded that the natural and artificial form factors cannot be used as a substitute for the real form factor for white poplar species in this province. The findings of this research can provide valuable basic information for determining the exact standing and saleable volume of each poplar tree, planning and management decisions in wood farming and related industries development in Chaharmahal and Bakhtiari province.
Keywords
Diameter class
Form factor
Slenderness coefficient
Wood farming
Subjects
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  • Receive Date 11 January 2025
  • Revise Date 07 February 2026
  • Accept Date 16 March 2025