Measures and yields of products and residues 33 17 



Craft (1976) found that after the merchantable sawlogs were removed from an 

 Appalachian hardwood stand by clearcutting, 69.3 tons per acre of green wood 

 residue remained — about 1.8 times greater than the weight of the sawtimber 

 removed. From these wastes, he produced an additional 4,800 bd ft of sawed 

 products and 51.6 tons of chippable wood per acre (fig. 16-5). 



Florida, Georgia, and South Carolina together generate an estimated 560 

 million cu ft of logging residues each year (Welch 1974). Harvesting West 

 Virginia hardwood stands produces an average of 467 cu ft per acre of residue 

 material 4 inches and larger dob at the small end and 4 feet long or longer (Martin 

 1975b). On Alabama clearcuts, about 8 cords per acre was left in residual trees, 

 tops of cut trees, unused bole sections, and above-ground portions of stumps 

 (Chappell and Beltz 1973). 



According to a recent survey (Porterfield 1976), 9.3 percent of the softwood 

 growing stock harvested in the United States and 17.5 percent of the hardwood 

 growing stock is left behind in the woods. Corresponding figures for the South 

 are 6.5 percent for softwood residues and 20. 1 percent for hardwood residues. 

 These figures do not include any cull trees or volume in trees less than 5 inches in 

 dbh which might be present on the site. Neither do they include below-ground 

 tree portions. 



Residues related to type of harvest. — Of all logging operations, hardwood 

 sawlog harvesting is the most wasteful. Logging only sawlogs to an 8-inch or 

 merchantable top utilizes, on the average, only 60 to 67 percent of the above- 

 ground wood in a deliquescent species like red oak (fig. 27-22) (Clark 1978). 

 When both sawlogs and stem pulpwood are harvested, 70 to 80 percent of the red 

 oak wood is utilized. However, whole tree chipping would increase wood 

 utilization by 26 to 46 percent as compared to logging to a 4-inch top (fig. 27-23) 

 and by up to 65 percent as compared to logging for sawlogs only. Increases for 

 an excurrent hardwood like yellow-poplar are somewhat less dramatic. 



A statewide study in Arkansas showed that hardwood sawlog operations 

 utilized 72 percent of the bole to a 3-inch top, while hardwood pulpwood 

 operations utilized 86 percent (Porterfield and von Segen 1976). For sawlogs, 

 utilization averaged 13 percent higher for tree-length harvesting operations than 

 for product-length operations where bucking was done in the woods. 



Gibbons (1977) also found that longwood harvesting tends to leave less 

 merchantable residue behind than shortwood operations. In a study of 3,000 

 acres of natural stands in the Midsouth, longwood harvesting left residues 

 equalling 39.6 percent of the total preharvest hardwood inventory; shortwood 

 harvesting left 43.2 percent; and a two-stage operation in which high value stock 

 is removed first followed by shortwood operation left the highest residue — 60.5 

 percent. 



Martin (1977) compared various harvesting options for a 1.7-acre stand of 

 predominantly yellow-poplar and red maple in southwest Virginia. "Near-com- 

 plete removal," in which the timber was harvested for sawlogs and whole-tree 

 chips, yielded 104 percent more salable material than would be expected if the 

 area had been cut for sawlogs only and 27 percent more than a pure pulpwood 

 harvest (table 27-126). 



