An aspen bark factor equation for Michigan

• Published in: Northern journal of applied forestry Vol. 8
• Main Author: Fowler G.W
• Format: Journal Article
• Language: English
• Published: 01.03.1991
• Subjects: bark products; diameter; diametre; diametro; forecasting; matematicas; mathematics; mathematique; michigan; populus; produit a base d' ecorce; technique de prevision; tecnicas de prediccion; trozos de corteza
• ISSN: 0742-6348; 1938-3762
• DOI: 10.1093/njaf/8.1.12

A multiple linear regression equation was developed to predict bark factor for aspen in Michigan as a function of tree height. Bark factors for bigtooth aspen were, in general, somewhat larger than bark factors for trembling aspen. Even though equations were developed for both species, the differences between the two equations were small, and not statistically significant, and a pooled equation based on both species is recommended. The pooled prediction equation yielded average relative errors from -2.3 to 0.87% and -1.02 to 3.83% at all tree heights for bigtooth and trembling aspen, respectively. For more accurate predictions of bark factor, the separate prediction equations for bigtooth and trembling aspen should be used. The new equations can be used to more accurately estimate tree and log wood volumes than when using a constant bark factor determined at breast height, which, in general, leads to underestimates of wood volumes.