UBC Theses and Dissertations
Bark estimation : bark volume and bark taper Grewal, Harjit Singh
The interest in alternate energy sources has prompted the study of tree bark. This thesis deals with the estimation of tree bark volume and bark taper above ground in the main stem. A bark volume equation was selected based on low average bias and standard error in all the 32 British Columbia tree species groups studied. The bark eguation predicts bark volume with little bias in most species with the exception of the very thick-barked ones such as coastal Douglas-fir. The bark volume equation was compared to two other approaches of estimation of bark volume and proved to be slightly superior. From the form of bark taper in the tree species studied a dual-eguation system was chosen to predict bark thickness at any pcint in the main bole of the tree. The system consists of one equation for the top portion and another for the bottom section. The two are joined together and are continous at the inflection pcinti Ihe taper prediction system works well for all the 32 species groups considered. However bias is relatively higher near the butt of the tree especially in thick-barked species. On the whole the system has the attributes of low bias and standard error. It also proved superior when compared to another method of predicting bark thickness.
Item Citations and Data