Merchantable Height in Lieu of Total Height in Stem Profile Equations
数学
统计
环境科学
作者
John H. Fowler,John C. Rennie
出处
期刊:Forest Science [Oxford University Press] 日期:1988-06-01卷期号:34 (2): 505-511被引量:8
标识
DOI:10.1093/forestscience/34.2.505
摘要
Abstract A procedure that uses merchantable height in lieu of total height in an existing stem profile equation was devised and tested using data from natural hardwood stands in Tennessee. Diameter at merchantable height was subtracted from each measured stem diameter. Consequently the transformed diameter at merchantable height becomes zero and provides compatibility with existing stem profile equations while maintaining tree stem profile. A stem profile model was fitted to the transformed data and evaluated for its ability to predict upper stem diameters. Standard errors of the estimate and biases indicate a good fit based on comparison with published results using total height. Equations to predict height at a specific diameter and volume between two heights derived from the stem profile equation modified for merchantable height are presented in an appendix. For. Sci. 34(2):505-511.