Somar Khalil⁽¹⁾ Ali Thabeet*⁽¹⁾ and Wadie khoury⁽¹⁾

(1). Department of Forestry and Ecology, Faculty of Agriculture, University of Aleppo, Aleppo, Syria.

(*Corresponding author: Dr. Ali Thabeet. E-Mail: alithabt@yahoo.fr).

Received: 24/11/2018                                Accepted: 03/01/2019

Abstract

This article included testing the height curves using some statistical parameters i.e., absolute mean of model error, relative mean of model error %, absolute standard deviation of the mean model error, model accuracy, model accuracy % and coefficient of determination R², to select the best model to estimate the height of Pinus brutia at the coastal mountains of Al Ghab in Syria, depending on one easy variable, which was the diameter of breast height. The objective of the study was to study height–diameter relationship as well as to obtain useful data in forest management. Ten height curve models were tested viz. Michailoff, Parabel, Prodan, Petterson, Korsun, Logarithmic, Pretzsch, Freese and Schreuder. The data of 104 trees was divided to estimate model parameters (71 trees) and the data for evaluation the models (33 trees). The results of model’s efficiency showed the adoption of the logarithmic model. This model had a high R-squared (R² = 93.38%), and the values of average model error value of 0.06, model accuracy of 0.792, model error % was 0.589 and standard deviation of model error was 0.529.

Keywords: Pinus brutia, Height curves, Growth modelling, Syria.

Full Paper in Arabic: PDF