Gross International 1/4-Inch Board Foot Volume -~Un forked Trees 



Gross International 1/4-inch board foot volume to a 6-inch top in an unforked tree 

 is predicted by 



where 



Vj = Predicted gross International 1/4-inch board foot volume to a 6-inch top 

 in an unforked tree 



V ,,„^ = Predicted gross merchantable cubic foot volume to a 6-inch top in an 

 unforked tree 



R = Predicted ratio of actual gross International 1/4-inch board foot volume 



to a 6-inch top in an unforked tree divided by predicted gross merchant- 

 able cubic foot volume to a 6- inch top in an unforked tree. 



This equation was fitted using weighted least squares regression through the origin. 

 The resulting ratio equations, ^j^q> ^t^^ of the form: 



' Rj^^ = do - cfiD"^ - d2D"^ - daD"^ 



where 



D = D.b.h. in inches. 



sp-NF specific, weighted regression coefficients for ^y/Q' ^^^^^ RMSQR, and the 

 )er of trees used can be found in table 7. The coefficient of determination, R^, 



The 



number of trees used 



is also included to help bridge several gaps where comparable values of RMSQR were not 

 computed. Methodological details can be found in appendix VI. 



Table 7. — Unforked tree gross International 1/4-inoh board foot volume 

 to a 6-inch top data base and reareseion results 



Species 



National Forest 



Number 

 of 

 trees 





"^0 



Reqression 



coefficients 







Relative 

 mean squared 

 residual 

 (RMSOR) 



Coefficient of 

 detennination 



(R'l 



White pine 



Santa Fe, Carson, Lincoln 



39 



6 



69196746 



7.52011366 



216 



348366 







00 



0.0179 



0.9842 



Enqelmann spruce-cork^ark fir 



Santa Fe, Carson, Lincoln 



117 



5 



98736288 



9.84791839 



-300 



8129080 



2,855 



342464 



.1018 



.9338 



Yellow pine 



Ul 



201 



7 



10051404 



7.97921881 



229 



556497 





00 





.9756 



Blackiack pine 



Lincoln, Coconino, Tonto 



613 



6 



84751736 



7.69491322 



221 



377226 





00 



.0753 



.9265 



Black;^ack pure 



Santa Fe, Carson 



20B 



7 



58122078 



8.51941410 



245 



097535 





00 





.9339 



Douqlas-f ir 



Lincoln, Tonto 



102 



6 



58735344 



.89271640 



243 



514909 





00 





.9711 



Douq las-fir 



Santa Fe , Carson 



70 



6 



59717456 



.89404735 



243 



877967 





00 



.0536 



.9543 



Aspen 



Santa Fe , Carson 



87 



6 



68808485 



-1.27685063 



-4 



5048044 



1,423 



985244 



.0492 



.9649 



White fir 



Lincoln 



40 



6 



24687520 



7.01994022 



201 



9587285 





00 



.0290 



.9749 



White fir 



Santa Fe , Carson 



47 



5 



73644537 



1.72093361 



74 



57378982 





00 



.0488 



.9611 



11 



