Fraction Cull in Merchantable Cubic Foot Volume Given the Tree Is Unsound — Unforked and 

 Forked Trees 



where 



The following model form is used to predict the fraction of an unsound tree's mer- 

 chantable cubic foot volume that is cull: 



Y 



FC = (1.0 - e 

 ■ mm ' 



FC = Predicted fraction cull in merchantable cubic foot volume to a specified top 



diameter given the tree is unsound 



h = A constant 

 m 



Y = A function of the tree's attributes and a specified top diameter between 3 

 and 8 inches, inside bark. 



The appropriate values of h^ and functions for Y^, the number of observations used, and 



the resulting RMSQR values are found in table 13. While these models are recommended 

 for use, equations predicting mean FC^ as a function of top diameter are also included 



in table 13 for those who choose not to use the FC equations. Methodological details 



can be found in appendix XII 



m 



19 



