Development of Stem Taper, height-diameter, diameter distribution and site index models for cilician fir (Abies cilicica carr.) stands

Reliable information on the growth and yield of tree species is essential for sustainable management of forest resources. The main components of the growth and yield of tree species; tree volume estimation, diameter-height relationships of trees, diameter distribution of stands and growth yield classification of growth environment. However, in our country, there is very limited information about the growth and yield of Taurus fir stands. For this purpose, in the first part, stem diameter estimation models are developed for estimation of stem diameter, tree height, merchantable volume and total volume for Taurus fir stands. 12 different stem diameter prediction models have been tested and based on criterion values, model developed by Clark et al. (1991) in terms of these four features were found to give the most successful results. In the second part, stem diameter model was developed by using Max and Burkhart (1976) stem diameter model and nonlinear mixed effect modeling approach. For the mixed-effect model, first, the most appropriate random-effect parameter combination was determined and then 10 different calibration alternatives were tested. In the third part, diameter-height models are developed by using Gompertz model for Taurus fir stands, using fixed-effect, calibrated fixed-effect and mixed-effect modeling approach. For the calibrated fixed-effect model and the mixed-effect model, calibration was performed using different tree numbers. In the fourth chapter, the diameter distribution of the Taurus fir stands is presented by Johnson's SB distribution function. Parameter estimation is based on percentile method. In the last section, dynamic site index models have been developed for Taurus fir stands. Chapman-Richards Log-Logistic, Bailey-Clutter, Lundqvist-Korf and Hossfeld models were tested. It is considered appropriate to use the model developed by Chapman-Richards in order to reveal age-height relationships for Taurus fir stands.