3. Calculated weights of foliage and branchwood components v/ere then adjusted so 

 that the sum of all component weights equaled the weight of each crown section actually 

 measured in the field, as shown in equation (2). 



where 



y' = adjusted weights 

 y = calculated weight from equation [1) 



R = ratio of measured weight for entire crown section to sum of estimated 



weights for all crown components 

 i = index for foliage and branchwood size classes 

 j = index for crown sections 

 k = index for individual branches 

 n = number of branches in a crowi section. 



Lastly, the adjusted weights of each crown component were summed for the entire tree. 



4. For each sample tree, the following accumulative fractions of total live crown 

 weight were calculated: 



?l = foliage 



P2 = Pi + 0- to 0.24-inch branchwood 

 P3 = P2 + 0.25- to 0.99-inch branchwood 

 P4 = P3 + 1.00- to 2.99-inch branchwood. 



A similar set of fractions was calculated for dead branchwood but without foliage. 

 These fractions were subjected to a least squares curve fitting analysis with d.b.h. as 

 the independent variable. The fraction of any branchwood component can be obtained as 

 the difference between two accumulative fractions. Fitting fractions of branchwood by 

 individual size classes to d.b.h. was attempted, but for some sets of data it was 

 difficult to find precise-fitting equations. Thus, accumulative fractions were used 

 because they provided well-behaved data sets for curve fitting. 



Fractions for dividing small tree boles and unmerchantable bole tips into diameter- 

 size classes of to 0.99 inch, 1.00 to 2.99 inches, and 3.00 inches and greater were 

 computed from volume estimates of each size class. Volume of each size class was 

 determined using length and diameter measurements of tip pieces. Tip pieces were 

 considered as cones and other pieces as frustums of cones. 



Bulk Density of Crowns 



Bulk density of live crowns was computed using ovendry weights of foliage alone, 

 and foliage and all branchwood together. Bulk density of foliage was computed two ways, 

 using crown volume determined with and without the needle-free cavity. Crown volumes 

 were computed from measurements of length and width of the top crown section and the 

 two lower crown sections combined. Top sections were considered as either cones or 

 paraboloids, depending on a shape designation assigned in the field. Lower sections 

 were treated as frustums of right cones. The needle-free cavity was treated as a 

 paraboloid. 



8 



