indicated before, measurements on these variables for 

 each sale were made from sale records. For example, 

 required corridor spacing (SPACE), measured in feet, is 

 specified in both the contractual clauses of the sale con- 

 tract and the timber sale report. 



Not to be confused with total costs, the following equa- 

 tions express costs in thousand board feet of timber har- 

 vested, a type of average cost. All values are expresssed 

 in 1985 dollars. 



Stump to Truck 



Stump-to-truck costs include costs associated with fell- 

 ing and bucking trees as well as skidding trees to the 

 landing and loading. These costs were the largest, ac- 

 counting for over half of the allowances modeled. Stump- 

 to-truck cost allowances averaged $85.02/M bd ft in the 

 Northern Region and $76.82 in the Intermountain Region. 



Table 2 shows the final cost estimation models for the 

 Regions studied along with the percentage of variation in 



Table 1— 



-Independent variables used in study 





Variable 



Description 



Units 





Sale Characteristics 





SPLT 



Selling price, lumber tally 



$ per M bd ft (Scribner) 



VOL 



Total sale volume harvested 



M bd ft (Scribner) 



VPA 



Volume per acre harvested 



M bd ft (Scribner) 



ACRES 



Acres harvested in sale 



Acres 



%TRA 



pprpont vnlump trar^nr vprripH 



I ol Ucl 1 L 



SPACE 



Corridor spacing 



Feet 



%GSL 



Percent volume group selection 



Percent 



%CC 



Percent volume clearcut, seedtree, 







or right-of-way 



Percent 



STEEP 



Sale area > 55 percent slope 



Acres 



FLAT 



Sale area 0-35 percent slope 



Acres 



#UNIT 



Number of cutting units 



Number 



YT 



Average maximum tractor yarding 



Feet 



UHAUL 



Unpaved haul distance 



Miles 



PHAUL 



Paved haul distance 



Miles 



ADBH 



Average tree diameter 



Inches 



TEMP 



Temporary road construction 



Miles 



NEW 



New road construction 



Miles 



RECON 



Old road reconstruction 



Miles 





Sale Requirements 





DUSTR 



Dust control restrictions 



1 = Yes 



= No 



Table 2 — Stump-to-truck cost estimation equations' 



Northern Region 



Intermountain Region 



Variable 



Coefficient 



Standard error Coefficient 



Standard error 



Constant 



%TRA 



VPA" 2 



1/VPA 



#UNITS 



YT 



1/ADBH 



FLAT" 2 



SPACE 



STEEP 



%GSL 



ACRES 2 



26.32 

 -.33 



140.40 

 760.00 



.10 

 .48 

 1.32x10"' 



5.60 

 .05 



40.17 

 8382 



.02 

 .11 



.44x10"' 



112.14 



-1.00 

 -6.35 



28 

 .03 

 871.49 

 -.70 

 -.08 



17.64 



.11 

 2.53 



12 

 .01 

 119.41 

 .24 

 .03 



.68 



.65 



'See table 7 for possible adjustment. 



3 



