Economic Feasibility Analyses 35 1 



28-7 $336,838— MODIFICATION OF 



CONVENTIONAL HARVESTING SYSTEMS TO 



RECOVER FOREST RESIDUES IN BALES' 



In southern forest tracts with a significant component of hardwoods among 

 merchantable southern pines, removal of essentially all above-ground biomass 

 at time of harvest eases natural or artificial regeneration of desired species. The 

 most successful systems to accomplish such removal have used in-woods whole- 

 tree chippers. The major disadvantages of these whole-tree chipping systems are 

 the large capital investment required, the logistical problems associated with 

 moving the equipment, and the economic restriction to operation on large tracts 

 only. 



Baling of logging residues, in combination with the feller-bunchers and grap- 

 ple skidders conventionally used by small-scale loggers, is an alternative that 

 requires less capital, is more portable, and can operate on smaller tracts than 

 whole-tree chipping systems. To test the concept a prototype baler was con- 

 structed to produce logging-residue bales about 3 by 3 by 31/2 feet in size and 

 weighing about 1,500 pounds (figs. 28-8 and 16-61). 



To illustrate how the baler might be incorporated into a conventional long- 

 wood system, consider the following example. 



First, assume that the conventional system without modification is a long- 

 wood system commonly found in the Piedmont and Upper Coastal Plain. The 

 operation consists of a feller-buncher with accumulating shear which fells and 

 piles material for chainsaw limbing and topping; the sawyers also fell and limb 

 material too large for the feller-buncher. Movement to the landing is accom- 

 plished with two grapple skidders. At the landing the trees are separated by 

 product type or tree size and loaded by a knuckleboom loader. Hauling is 

 accomplished with two truck-tractors and four set-out trailers which allows the 

 trucking function to be independent of the logging system production. 



Now, modify this system to include the use of a residue baler. The limbing 

 and topping function will be moved to the landing, but one sawyer will be left at 

 the stump to fell oversize trees. The feller-buncher will fell and pile all remain- 

 ing stems on the stand. Skidder productivity, measured in terms of conventional 

 products, is expected to drop about 25 percent because of whole-tree skidding. 

 Limbing and topping will take place at the landing and conventional products 

 will be loaded as before. The logging residues left near the baler will be placed 

 into the baler infeed by the loader for processing. As long as the infeed is 

 charged, shearing, compaction, tying, and bale discharge functions will be 

 automatic. As bales are produced, they will be stacked for re-loading when a 

 truck load has been accumulated. 



Performance of the conventional system was simulated on a 36-acre mixed 

 pine-hardwood stand in the Upper Coastal Plain of the deep South. The stand 



^Abstracted from Stuart et al. (1981). 



