RESEARCH SUMMARY 



Two timber sales in north Idaho were experimentally relogged to determine 

 if residues could be reduced through imposition of strict wood utilization standards . 

 Re logging took place in 1975, one year following the initial logging. The 57-acre 

 (23. 1-ha) Danby Ridge sale, which had never been logged before, had an over- 

 story of mixed sawtimber of medium stocking, 160 years old, and an understory 

 of mixed polesize material of poor stocking, 80 years old. The 23-acre (9.3-ha) 

 Lee Creek sale, v/hich had been logged for cedar in the 1950's, had an overstory 

 of mixed, 100-year-old sawtimber of medium stocking, with an understory of 

 60-year-old, poorly stocked, mixed polesize material. 



The initial logging removed only green sawlogs 8 feet (2.44 m) long to a 10- 

 inch (25.4-cm) top, or 10 feet (3.05 m) long to an 8-inch (20.32-cm) top, con- 

 taining a minimum of 10 board feet (3 ft 3 ) and more than one-third sound. On 

 Danby Ridge, about 15.7 thousand board feet per acre was harvested; about 6.7 

 thousand board feet per acre remained as dead and green residue; and about 0.1 

 thousand board feet per acre remained as residual timber. Volumes on Lee Creek 

 were 9.8 thousand board feet harvested. 6.5 thousand board feet residue, and 

 2.5 thousand board feet residual timber. 



On a 5-acre study plot, post-harvest residues 3 inches (7.62 cm) in diameter 

 and larger amounted to 8, 940 cubic feet (253 m 3 ) on Danby Ridge and 8, 978 cubic 

 feet (255 m 3 ) on Lee Creek. Relogging to recover material suitable for pulp, 

 shake bolts, fence posts, and sawlogs with a 4-inch (10.16-cm) top, resulted in 

 recovery of 5,291 cubic feet (150 m 3 ) on Danby Ridge, a residue reduction of 

 59 percent. An additional 3,931 cubic feet (113 m 3 )was harvested on Lee Creek, 

 a residue reduction of 44 percent. 



On Danby Ridge, most of the salvage was suitable only for pulp, whereas on 

 Lee Creek many pieces qualified for other products. Salvaged wood was skidded 

 to the roadside but none was actually sold because the market for such materials 

 softened as the study was nearing completion. 



Production rates were measured for two harvesting machines common to 

 north Idaho — a Caterpillar D2 tractor and a John Deere 540 rubber-tired skidder. 

 On Danby Ridge, the tractor skidded 623 pieces (6,026 ft 3 ) (168. 7 m 3 ) an average 

 one-way distance of 70 feet (21.34 m) in 44 hours. On Lee Creek, the skidder 

 moved 625 pieces (3,062 ft 3 ) (85.7 m 3 ) an average 204 feet (62. 18 m) in 22 hours. 

 Because of larger piece size on Danby Ridge, the two machines moved about the 

 same volume of wood per hour. 



The skidder operated at below payload capacity because residues were in 

 small pieces. The tractor, although working close to capacity, was impeded by 

 not having a winch. Until special harvesting equipment designed to handle re- 

 sidues is available, the small, multi-purpose skidder will remain the most prac- 

 tical machine for salvage logging. 



