Whole-Tree Utilization of Southern Pine Advanced By Developments in Mechanical Conversion

In 1963, approximately 30 percent of the dry weight of above- and below-ground parts of southern pine trees ended as dry surfaced lumber or paper, and the remaining 70 per cent was largely unused. By 1990, computer-controlled chipping headrigs, thin-kerf saws, lamination of lumber from rotary-peeled veneer, high-yield pulping processes, and more intensive use of roots, bark, and tops will likely double the yield of lumber, paper, bark products, and reconstituted board to 60 percent of the dry weight of above- and below-ground tree parts.The 1963 percentage assumes that, on a weight basis, 48 per cent of the bark-free merchantable stem ended as rough lumber with a further loss of 25 percent during planing; that 28 percent ended as pulp chips pulped with 50-percent yield; and that 24 percent of the merchantable stem ended as saw dust. The 1980 percentage assumes that 60 percent of the bark-free merchantable stem will end as rough lumber, with only 10 percent further loss during planing; that 35 percent will end as pulp chips to be pulped by 70-percent-yield processes, and that only 5 percent of merchantable stem volume will end as sawdust. For the 1980 figures, it is projected that half of all stumps will be harvested with 30- percent loss of fiber and pulped with 50-percent yield, that one-fourth of all bark tonnage harvested will end as a low-value residual resulting from chemical utilization and that the balance will end as profitable products, that one-fourth of the total tonnage of tops and branches available will be reconstituted as board products; and that needles may be used, but probably less than 1 percent of the total tree weight.

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