Generalized nonlinear height-diameter models for a Cryptomeria fortunei plantation in the Pingba region of Guizhou Province, China

The relationship between height and diameter (H-D) is an important component in forest growth and yield models, and a better understanding of the relationship will improve forest monitoring, management, and biomass estimation. Sixteen nonlinear growth functions were fitted to H-D data for 1261 trees from a Cryptomeria fortunei plantation in the Pingba region of Guizhou Province, China. Of the 1261 trees, 80% were randomly selected for model calibration, while the remaining trees were reserved for model validation. All models were evaluated and compared by means of multiple-model performance criteria. Although all 16 models showed a good fit to the dataset and each of them accounted for more than 75% of the total variation in height, a large difference in asymptotic estimates was observed. The Chapman-Richards, Weibull, and Naslund models were recommended for C. fortunei plantations, due to their satisfactory height prediction and biological interpretability