3400 



Chapter 27 



Table 27-65C — Regression equations for estimating above-stump green cubic-foot vol- 

 ume of the whole tree and its components for southern red oak trees 5 to 22 inches in dbh 

 from natural stands in the Southeast, using dbh and total height as independent variables 

 (Clark et al. 1980c)— Continued 



Cubic-foot 



volume 



(Y) 



Regression equation' 



Coefficient of 

 determination 



(R2) 



Standard 

 error^ 



(Sy.x)' 



Number trees 

 sampled 



(N) 



Crown material (all 



branches and 



top wood <4 



inches d.i.b. 



excluding 



foliage): 



Wood Y 



Bark Y 



Wood & bark . . Y 



0.000415 (D^Th)'-^^^^^ 

 0.000068 (D^Th)'- 12860 



0.000465 (D^Th)'-^'^' 



Crown material 

 ^2.0 inches 

 d.o.b.: 



Wood 



Bark 



Wood & bark . 



0.000074 (D^Th)' 1^306 

 0.000004 (D^Th)' 35^^i 

 0.000068 (D^Th)'-^^^^^ 



.75 

 .83 

 .77 



^Y = bo(D2Th)^' 

 where: 



Y = component volume in cubic feet. 



D = dbh in inches 



Th = total height of tree in feet, 



bghi = regression coefficients. 

 ^Standard error in logjo form. 

 ^Additional statistics for computation of confidence intervals: 



X(x 

 S(x 



4.1055 and x = 3.9785 for equations based on 29 trees and 

 0.5235 and x = 4.2471 for equations based on 17 trees. 



