Figure 2. — These ponderosa pine show the variety of crown structure encountered in the 



sampling. 



Measurements 



On sample trees, crowns were visually divided into two or three horizontally 

 partitioned live sections and one dead section that contained all dead branches within 

 as well as below the live crown. Boundaries between live crown sections were located 

 where diameters and lengths of branches changed distinctly. If changes in cro\\m 

 structure were not apparent, two crown sections were identified, with the boundary 

 between them located near the middle of the crown. Weights, moisture contents, and 

 crown volumes were determined by crown sections in order to characterize crouTi prop- 

 erties as accurately as possible. 



Trees less than 6 inches d.b.h. were felled, then limbed; larger trees were climbed 

 and limbed by workers using climbing spurs and safety belt (fig. 3). All branches were 

 cut flush with the bole and separated by crown section. Basal diameters of all live 

 branches were measured beyond the butt swell, 1 to 2 inches from the cut end. 



Weights of each crown section and bole tips to 1-, 2-, 3-, 4-, and 6-inch diameter 

 outside bark, were measured using spring scales of varying capacity, depending on 

 amount of material. Canvas and nylon slings held the crown material for weighing. 

 From each live section, a sample branch was randomly picked and from each dead section, 

 a sample branch was picked that appeared average in size among the dead branches. The 

 sample branches were divided into foliage and branchwood by size classes. The foliage 

 and branchwood in each size class were weighed separately and moisture contents deter- 

 mined from duplicate samples ovendried at 100° C for 24 hours. In all, 22 to 34 

 moisture samples were taken for each tree. For small trees, most or all of the entire 

 crown was often ovendried. 



4 



