Longitudial variation in wood specific gravity of planted loblolly pine in the southern United States

Loblolly pine (Pinus taeda L.) is the most important plantation species grown in the southern United States, having more than half of the standing pine volume. Wood from loblolly pine is a principal source of raw material for the pulp and paper industry and is desirable for the production of lumber and composite wood products. The quality of wood produced from a loblolly pine tree is defined by its physical and mechanical properties. Of these, specific gravity (SG) is an important measure of wood quality (Panshin and de Zeeuw 1980), and varies both with tree height (Megraw 1985; Zobel and van Buijtenen 1989) and with geographic locations (Clark and Daniels 2002; Jordan et al. 2008). The objectives of the present study were to model the regional and within tree variation in disk SG of loblolly pine.