Development of dynamic growth models for taurus cedar (cedrus libani a. rich.) stands in the lakes region

In this study, models were developed for stem taper, height-diameter relationships, diameter distribution, site index, aboveground biomass estimation for whole trees and their components, and single-tree diameter increment for pure and natural Taurus cedar (Cedrus libani) trees and stands in the Lakes Region. In the first section, stem taper models were developed using 14 different taper equations. Among these, the model proposed by Jiang et al. (2005) yielded the most accurate results for estimating stem diameter, tree height, commercial volume, and total stem volume. In the second section, simple and generalized height-diameter models were tested using Ordinary Nonlinear Least Squares (ONLS), Nonlinear Mixed-Effects Modeling (NLME), and Quantile Regression (QR) techniques. The Chapman-Richards model produced the most successful results, and various calibration alternatives of this model were also evaluated. In the third section, the three-parameter Weibull Probability Density Function was used to characterize stand structure. For parameter estimation, four different approaches were applied: the Parameter Prediction (PP) method, the Moment-Based Parameter Estimation (MPR) method, the Percentile-Based Parameter Estimation (PPR) method, and a Hybrid (HYB) method. In the fourth section, dynamic site index models were developed for Taurus cedar stands using four different site index functions. The Chapman-Richards model was found to be the most suitable option for modeling the age-height relationship. In the fifth section, biomass estimation models were developed for aboveground whole tree and its components. To enable simultaneous estimation of tree and component biomass, Nonlinear Seemingly Unrelated Regression (NSUR) analysis was employed. In the sixth and final section, a single-tree diameter increment model was developed for Taurus cedar using variables such as diameter at breast height (DBH), stand age, site index, stand density, mean stand diameter, and competition indices. The model was used to estimate the five-year diameter increment of individual trees.