Table 7. 



--Simple linear regressions for estimating weight of foliage and branahwood components of individual branches 

 from dominant and oodominant trees. Regressions are of the form Inw = a + bdndj where w = weight, lb; 

 d = branch basal diameter, inches. Bias was corrected as shown in equation (1) 



Stat- ::::::::::: 

 istic : DF : GF : AF : WH : C : S : L : PP : LP : WP : WBP 



FOLIAGE 



a -0.6747 -0.4568 -0.6519 -0.5089 -0.6891 -0.5180 -1.545 -0.9641 -0.9175 -1.128 -0.9265 

 b 2.121 2.204 2.076 2.117 2.114 2.169 2.023 2. 035 2.260 2.018 2.292 



n 64 65 56 61 69 44 51 48 47 64 40 



r2 .95 .92 .90 .96 .95 .95 .94 .92 .87 .94 .88 



TO 0.24 INCH 



a -1.465 -1.506 -1.233 -1.192 -2.253 -1.082 -1.228 -3.424 -1.224 -1.626 -1.844 



b 2.000 2.083 2.268 2.083 2.021 2.336 2.158 1.180 ' 2.490 2.202 1.915 



n 56 60 52 57 63 38 53 39 45 61 37 



r2 .96 .93 .91 .96 .93 .96 .95 .74 .95 .91 .70 



0.25 TO 0.99 INCH 



a -.9315 -1.120 -.5650 -.8144 -1.311 -.9377 -.9763 -1.070 -1.077 -1.378 -1.008 



b 2.126 2.690 3.268 2.390 2.192 2.694 2.426 2.399 2.607 2.638 2.664 



n 40 37 35 30 44 30 23 41 28 45 24 



r2 .91 .91 .91 .86 .89 .92 .87 .94 .92 .91 .79 



1.00 TO 2.99 INCHES 



a -1.000 -1.485 -1.675 -1.168 -1.318 -.9333 -.7957 -1.125 -1.159 -2.894 -2.180 



b 3.002 3.960 7.047 3.912 3.536 3.184 1.861 2.490 3.199 5.106 3.351 



n 20 13 9 12 15 12 10 18 11 14 4 



.83 .83 .79 .85 .96 .78 .63 .89 .80 .91 .76 



.2 



3.00 INCHES AND GREATER- 

 a -3.687 

 b 4.363 

 n 11 



81 



1/ 



For species other than PP, material 3 inches and larger either did not exist or was approximated by means 



other than regression analysis. 



Branch Weights 



Using logarithmic transformations, weights of foliage and branch components for 

 individual branches were highly correlated with branch basal diameters, as shown in 

 table 7 for dominants and table 8 for intermediates. The pattern of weight curves for 

 individual branch components shown in figure 9 for grand fir is typical of most species. 

 Except for western larch, the 1- to 3-inch branchwood class has the steepest regression 

 slopes showing a rapid increase in the weight of the largest diameter material as branch 

 basal diameter increases. 



Foliage weight per branch related closely to species tolerance with the most toler- 

 ant species supporting the most foliage (fig. 10). For the species groups in figure 10, 

 deviations in foliage weight between individual species and the group average were 

 mostly less than 10 percent of the group average. The maximum deviation was a negative 

 25 percent for western white pine. 



Foliage and Branchwood Fractions 



For each species, five or six equations were required to describe the accumulative 

 fractions of live and dead crown components. Most equations were exponential, and for 

 live crown weight they provided close-fitting relationships between accumulative crown 

 fractions and d.b.h. (fig. 11). Because of variation in retention of dead branchwood, 

 accumulative fractions of dead crown components were less closely correlated with d.b.h. 

 than accumulative fractions of live crown components. Equations for accumulative crown 

 fractions and conditions for maintaining reasonable solutions at limits of the data are 

 in appendix III. 



20 



