Generalized height-diameter models for Picea orientalis L.

The purpose of this paper is to compare major models for height estimation of Picea orientalis L trees based on the individual tree diameter and certain other stand variables. The data were collected from 440 trees of pure and even-aged P. orientalis stands that are located near Artvin in the northeastern part of Turkey. The data from 406 trees were used for model development and the remaining data were reserved for model validation. A total of 17 non-linear models were fitted to 406 trees. Mean square errors and R2 values for the 17 models showed that some models roduced similar height estimation. The model [8] gave the best height estimates for P. orientalis with the highest R2 (0.8703) and the lowest mean square error (5.47). Validation of the models using independent data sets showed that model [8] and [16] gave the best height predictions for this particular dataset.