Wood-bark density of hybrid sweetgum stems at an afforested site in north LouisianaThis article is part of a larger document. View the larger document here.
This is the third in a series of studies to quantify yields of hybrid sweetgum (Liquidambar formosana x styraciflua) biomass at an afforested site in north Louisiana. Pooling across herbicide and varietal treatments to produce a single model system to estimate weight was determined to be statistically appropriate on the 2-year-old (1-0) seedling stock. An equation constructed from that study, where moisture content on the oven-dry basis averaged 107.5 percent (51.8 percent wet-basis), estimated the weight of standing trees. Field measurements of stem diameter occurred at 1-foot increments along the height of the stem beginning at the groundline, with height determined from pole measurements. The volume of each section was calculated using Smalian’s formula and summed to provide total stem volume. Bulk density was calculated as pounds per cubic foot (pcf) green, basic density was calculated as oven-dry weight per cubic foot green volume, and specific gravity was the ratio of basic density to the density of water. Bulk density, basic density, and specific gravity were all calculated outside bark. Mean values for bulk density, basic density and specific gravity were 61.6 pcf, 29.7 pcf, and 0.48, respectively. The results suggested the hybrid sweetgum density properties exceeded published values for native sweetgum (L. styraciflua), while moisture content was lower. Seasonal influences could have affected moisture content and bulk density. However, basic density and specific gravity findings suggest potential exists to benefit a number of both traditional (e.g., logging, pulp, and paper) and newer (pellet, biofuel) industries, as wood properties correlate strongly with product output in these industries.