Study Methods and 

 Reliability of Estimates 



Study design prescribed three basic measurements of growing stock trees on 

 active logging operations: 



1. Net volume of saw logs harvested from product trees measured on a logging 

 operation. 



2. Net volume of residues from the same trees. 



3. Net volume of residues from trees cut or damaged as a result of felling and 

 skidding product trees. 



These measurements were related in compilation to determine volume of residues 

 as a jiorcent of saw log volumo. Measurements provided both gross and net cubic-foot 

 volumes for all measured growing stock trees. Careful scaling provided gross and net 

 board-foot volumes to fixed and variable tops for measured sawtimber trees. Species, 

 d.b.h. , total height, overutilization (by Forest Survey standards), and whether res- 

 idues resulted from felling or skidding were also recorded. 



The number of basic sample units used in the study corresponded to the number of 

 logging operations on which measurements were taken. The number of samples for each 

 State shown in the following tabulation were drawn from a list of active logging oper- 

 ations in each State. 



State 



Number of operations 



Western South Dakota 

 Wyoming 



12 

 9 

 4 

 19 

 44 



Utah 



Colorado 



10 



