Development of dimension lumber grade and yield estimates for yellow-poplar sawlogs and trees
The projected increased demands for forest products and the dwindling softwood supplies are expected to lead to increased pressure on the hardwood raw material base.
The Eastern United States' hardwood region offers a great potential for supplying the nation's growing demand for wood based products. The problem in realizing this potential is that eastern hardwoods in general, and yellow-poplar (Liriodendron tulipifera L.) in particular, are underutilized.
At present, dimension lumber used in light frame construction is almost exclusively manufactured from softwood species. Recent literature, research, and conferences have pointed to the possibility and feasibility of using yellow-poplar dimension lumber. It is an accepted species for light framing in the grading rules of the Northern Hardwood and Pine Manufacturers Association. Yet, if utilization of yellow-poplar as a dimension lumber species is to be realized, lumber yields and residue volumes for various grade and size classes of yellow-poplar trees must be available in order to allow land managers to assess the value of standing yellow-poplar timber, develop sound management objectives for the species, and encourage its wide use. Similar yield and residue information for yellow-poplar sawlogs is also needed to allow sawmill operators to evaluate the economic feasibility of producing dimension lumber from yellow-poplar logs.
Yellow-poplar log grades were established to stratify yellow-poplar logs into salable dimension lumber classes when the lumber was manufactured by the Saw-Dry-Rip manufacturing system. These log grades are based on the southern pine log grades with log defect exclusion limits. Dimension lumber and residue yields for the yellow-poplar dimension lumber log grades are presented.
The use of various grading schemes for stratifying yellow-poplar trees into salable dimension lumber classes was evaluated. It was found that estimates of salable dimension lumber yield from pooled data yielded better results than estimates using tree grades for stratification. Estimates for the dimension lumber yield are listed.
Producing dimension lumber from yellow-poplar logs of various diameters and quality classes was evaluated in light of producing alternate products using net revenue graphs. The net revenue graphs suggested that a sawmill should utilize the lower diameter and lower quality logs for dimension lumber production.