Measures and yields of products and residues 33 15 



complete-tree biomass data on 67 six-inch-diameter pine-site hardwoods of 22 

 species, had average weight distribution as follows (lateral roots severed at a 3- 

 foot radius): 



Tree portion Green weight Ovendry weight 



— Percent of complete tree — 



Central stump-root system 21 .7 20.6 



Stem with bark 57.7 59.2 



Branches 0.5-inch-ciiameter and larger 11.6 11.9 



Twigs 5.2 5.3 



Foliage 3.8 3.0 



100.0 100.0 



A summary of weight distribution tables and equations in this text is given in 

 table 27-97. For bark residue quantities see chapter 13, for roots chapter 14, and 

 for foliage chapter 15. 



Cost (1978) studied the volumes of bark-free above-ground wood in hard- 

 wood trees growing on about 4 million acres in the Mountain Region of North 

 Carolina. He estimated the total volume of above-ground wood (bark-free) on 

 this acreage at 7.5 billion cubic feet; 30 percent of this wood is in stumps, tops, 

 limbs, and saplings. For both sawtimber and pole timber, about 80 percent of the 

 wood volume is confined to the merchantable stem and about 20 percent is in the 

 nonmerchantable portions. But the distribution of wood volume within the 

 nonmerchantable portions varies with tree size: for sawtimber, 4 percent is in the 

 stump, 2 percent in the top, and 13 percent in limbs; for poletimber, the 

 corresponding proportions are 6, 8, and 6 percent (table 16-1). 



In Louisiana and Alabama, hardwoods cut for pulp wood averaged 24 cubic 

 feet in above-ground volume, excluding bark; 15 to 20 percent of that was in tree 

 tops, 5 percent in lopped limbs, 5 percent in stumps, and only 70 to 75 percent 

 was actually removed as pulpwood (Beltz 1976). Lopped limbs were those ^ 1- 

 inch diameter at limb collar and lopped from the portion of the bole used. Tree 

 tops were residual crowns. 



Measuring logging residues. — ^The first step toward utilization of logging 

 residues is determining just how much is available. This can be done by weigh- 

 ing all logging residues on conventional sample plots. However, a much quicker 

 procedure now in widespread use is the line intersect method. 



In line intersect sampling (Martin 1976a), a line is established on the cutover 

 area and the diamters of all logging residues that cross the line are measured at 

 the point of intersection. Sample lines may be continuous or segmented, and 

 they may be oriented either systematically or randomly. The volume of residue 

 is then estimated by using the equation: 



V = ^xl^ (27-45) 



where: 8L 144 



V = volume of residue per acre, cubic feet 



d = diameter of residue point of intersection, inches 



L = length of sample line, feet 



