Comparative analysis of four stem taper models for Quercus glauca in Mount Halla, Jeju Island, South Korea

Abstract

This study was conducted to fit the diameter-height data of Quercus glauca in Jeju Island, South Korea to the four commonly used stem taper equations and to evaluate the performance of the four stem taper models using four statistical criteria: Fit index (FI), root mean square error (RMSE), bias ( ), and absolute mean difference (AMD). Results showed that the Kozak02 stem taper equation provided the best FI (0.9847), RMSE(1.5745), (-0.0030 cm) and AMD (1.0990 cm) while Max and Burkhart model had the poorest performance among the four stem taper models based on the four evaluation statistics (FI : 0.9793, RMSE : 1.8272, : 0.3040 cm and AMD : 1.3060 cm). These stem taper equations can serve as a useful tool for forest managers in estimating the diameter outside bark at any given height, merchantable stem volumes and total stem volumes of the standing trees of Quercus glauca in the Gotjawal forests located in Mount Halla, Jeju Island, South Korea.