For cedar, the differences in weight estimates seem small enough to ignore from a 

 practical point of view. For both species, crown ratio was sampled over a narrow range; 

 thus, evaluation of the relationship between crown weight and crown ratio was restrained. 



Over the range of d.b.h. studied, intermediates supported approximately 2 to 6 

 times as much dead branch weight as dominants. Douglas-fir intermediates had 4 to 6 

 times as much dead branchwood as dominants, the highest ratio of any species. Ponderosa 

 pine showed the lowest ratio, the intermediates supporting nearly 2 times as much dead- 

 wood as the dominants. The ratios increased substantially for trees less than 3 inches 

 d.b.h. because little dead branchwood was found on small dominants. Although the per- 

 cent of total crown that is dead increased with increasing d.b.h. for dominants, it 

 appeared nearly constant for intermediates. For intermediates 2 inches and greater in 

 d.b.h., the dead percentage for ponderosa pine and Douglas-fir averaged about 25 percent 

 and for grand fir and western redcedar about 12 percent. 



The influence of crovm class on crown weight per tree suggests that for activities 

 such as fuel appraisal, crown class can be disregarded for estimating crown weights of 

 tolerant species. However, for intolerant species, weight estimates should be partly 

 based on either crown class or crown ratio. Likewise, for estimation of total stand 

 biomass involving intolerant or moderately tolerant species, crown class or crown ratio 

 should be accounted for in estimating crown weight. 



Trees 1 inch and less in d.b.h. . --Excerpt for grand fir, live crowns of intermediates 

 under 2 inches d.b.h. weighed less than crowns of dominants (table 3). For trees greater 

 than 8 feet in height, the equation for grand fir intermediates predicts greater crown 

 weights than the equation for dominants. This holds true even after eliminating inter- 

 mediate No. 835 from the regression analysis because it appeared unusually heavy. Ap- 

 parently, several intermediates, at least 35 to 45 years of age and 8 to 10 feet tall, 

 were responsible for the large weight predictions of intermediates. Although short in 

 height, they had bushy crowns containing lots of foliage and branchwood. At comparable 

 heights, the faster grown dominant trees contained less branchwood and foliage. 



Similar to the trees greater than 1 inch d.b.h., crown weights for intolerant 

 species were considerably greater for dominants than for intermediates. For tolerant 

 species, crown weight predictions differ only a small amount between crown classes 

 (table 3). Crown ratios averaged less for intermediates of all species and probably 

 account for some of the weight differences between crovm classes. 



The percent of total crown that is dead varied considerably among individual- trees. 

 The percent dead for the intermediates averaged: 



The percent dead of intermediates is substantially greater than for the dominants, 

 probably due to effects of shading. Among the intermediates, the tolerant species ex- 

 hibited a smaller fraction of dead branchwood. 



The same procedure used in selecting equations for crown weights was applied to 

 bole weights (including bark) for trees 4 inches and less in d.b.h. (table 5). Up to 

 2 inches d.b.h., estimated bole weights for all species are almost the same; however, 

 beyond 2 inches d.b.h., large differences among some species appear (fig. 7). For 



Species 



Percent dead 



Ponderosa pine 

 Douglas-fir 

 Western redcedar 

 Grand fir 



18.3 

 11.8 

 6.0 

 2.6 



Bole Weights 



16 



