FNR-116
forestry & natural resources
MARKETING AND UTILIZATION 
Structural Lumber A New Market for Yellow-Poplar
John F. Senft and Daniel L. Cassens
Problem Statement
Yellow-poplar (Liriodendron tulipifera L.) is a hardwood species native to Indiana and to most states east of the Mississippi; it grows tall and straight and is abundant. The wood is relatively soft, but strong, and easily machined. However, yellow-poplar is one of the lower valued hardwoods, difficult to market and, therefore, producers of yellow-poplar lumber have been searching for new and better markets.
When this country was first settled, yellow-poplar enjoyed wide use in the Midwest. It was available everywhere and was a favorite framing and siding material. It could be produced in large sizes, was easily nailed, and the heart-wood was relatively durable, making it an ideal siding material. In more recent times yellow-poplar was widely used in the furniture industry primarily for interior framing and as core stock for veneered table tops and panels. Its light weight and ease of drying and machining were desirable characteristics. The advent of less expensive, more dimensionally stable particleboard and fiberboard products, however, rapidly pushed yellow-poplar out of this market. What was once a prime species in hardwood markets is now difficult to market even with prices that have not kept pace with inflation.
At the same time, softwoods, the now traditional house framing and structural species in the United States, have become more expensive, due in large measure to utilization of smaller diameter, second-growth timber and increased transportation and handling costs. Consequently, yellow-poplar has been suggested as a possible substitute for softwoods in the structural marketplace (housing, farm build-
ings, light industrial framing). The question is: would yellow-poplar provide a profitable, feasible addition to the structural lumber market in the Midwest?
Properties of Yellow-Poplar
The physical and mechanical properties of yellow-poplar as well as its general characteristics are described in the Wood Handbook (11). Yellow-poplar sapwood is white, while the heartwood is yellowish brown and sometimes streaked with purple, green, black, blue, or red; these mineral streaks do not affect the strength properties of the wood. The wood is generally straight-grained and rather uniform in texture. The wood from old-growth trees is soft, moderately low in density, and relatively low in strength properties. Second-growth stock tends to be somewhat harder, heavier, and stronger. The wood dries relatively easily and reacts comparatively well in its machining properties and in nailing and screw-holding properties. Yellow-poplar is listed as slightly resistant to decay.
The physical and mechanical properties of yellow-poplar are listed in Table 1 along with properties of selected hardwoods and several conifers commonly used in construction. The values listed are for clear wood in the green moisture content condition (2).
The properties shown in Table 1 are those used by architects and engineers in designing structures and, perhaps, need some explanation. Wood specific gravity (or the more commonly used measure of unit weight, density in pounds per cubic foot) is generally directly related to its strength; the higher the specific gravity, the stronger a wood is. Specific gravity also gives an indication of how heavy the wood
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