Development of regional stem taper models for some important tree species of Turkey: Case study of Bucak

Compatible stem taper and volume models were developed for Brutian pine (Pinus brutia Ten.), Cedar of Lebanon (Cedrus libani A. Rich.), and Cilicica fir (Abies cilicica Carr.) in Bucak forest region of Southern Turkey. The proposed models generally performed better for the whole tree for all tree species. Diameter and volume predictions at 10 points along the stem were made to verify the accuracy and precision of these models for the three species. More specifically, differences among different tree species in one region and regional differences of the taper equation were examined using the nonlinear extra sum of squares method. The results of the non-liner extra sum of squares method indicated that species-specific taper equations for estimating diameters along the stem and predicting merchantable or total volume for each region are required.