Study of Distance Sampling Methods for Estimating Quantitative Characteristics of Forest

Awareness of the density and canopy cover of Zagros forests is important for their preservation, restoration and expansion. The purpose of this study was to introduce the most appropriate estimator of distance sampling methods for estimating quantitative characteristics of these forests. For this purpose, trees and their two large and small crown diameters in 33 circular sample plots in Kermanshah province inventoried. Within each circular plots, seven distance sampling methods such as Nearest individual, Nearest neighbor, second nearest neighbor, Compound, T-square, Joint-point method and Point-centered quarter were sampled. After calculating the density and canopy cover of trees in circular method (true value) and distance sampling method estimators, the results of this estimators were compared with circular plots with using accuracy. The results showed that among 16 estimators of above distance sampling methods, the most suitable estimator for density and canopy cover of this forest was PCQ3 estimator.