Selected mechanical and physical properties of Chinese tallow tree juvenile wood

Chinese tallow tree is a noxious, invasive plant in the Southeastern United States. It is generally considered a nuisance and has no current commercial use. The objective of this research was to determine the moduli of rupture (MOR) and elasticity (MOE) of the stem wood of this species at different vertical sampling locations. Three Chinese tallow trees were felled and cut into bolts before sampling along the east and west radial directions. It was found that Chinese tallow tree has sufficient bending strength for low to medium structural uses. Tree, bolt, and sampling direction were all found to be significant sources of variation for the MOR and MOE data. Amajor change has occurred in the species composition of the forests of the Southeastern United States. The Chinese tallow tree (Triadica sebifera syn. Sapium sebiferum) has become a serious invasive species throughout this region. A forest inventory from the 1990s revealed 1,035,000 forestland acres with at least 1.6 ft basal area/ac ( 1.0 inch DBH/ac) in Chinese tallow tree for three regions: east Texas, Louisiana, and Mississippi. These Chinese tallow tree “occupied” forests contained 35,997,000 tons, or 2.562 tons/ac of woody biomass—an amount equivalent to 7.4 percent of the total tree biomass in these forests (Rudis 2003). Because it grows rapidly, has seeds rich in oils, abundant flowers, and colorful fall foliage, it has been widely planted as a potential crop and as an ornamental (Jubinsky and Anderson 1996, Bruce et al. 1997). Chinese tallow tree has become naturalized from the Gulf Coast of Texas to the Atlantic Coast of North Carolina (Jubinsky and Anderson 1996, Bruce et al. 1997, Grace 1998). This invasive exotic species is currently considered noxious by the USDA Natural Resources Conservation Service (2008). A noxious organism is considered to have a harmful effect on the natural environment. It produces aboveground biomass at a significantly faster rate compared to most other tree species (Harcombe et al. 1993, Rockwood et al. 1993) and is able to quickly establish a dense stand. One of the barriers to Chinese tallow tree utilization is the fear that the successful development of an industrial use for the species will encourage people to cultivate the already noxious species. Accordingly, most past research emphasis on this species has been on eradication, not utilization. The successful development of commercial uses for this species might be able to aid in underwriting the costs associated with its control/eradication. The crooked stem prohibits the tree from being used for most conventional lumber applications. However, some recent studies have been initiated to better understand the basic properties of this species. Eberhardt et al. (2007) examined the chemical properties of the species. Previous studies have The authors are, respectively, Professor, Louisiana Forest Products Development Center, School of Renewable Natural Resources, Louisiana State Univ. AgCenter, Baton Rouge, Louisiana ([email protected]); Project Leader and Research Scientist, USDA Forest Serv., Southern Research Sta., Pineville, Louisiana ([email protected], [email protected]); Director, Microscopy Center, Univ. of Louisiana-Lafayette, Lafayette, Louisiana ([email protected]); and Professor/Director, Tennessee Forest Products Development Center, Univ. of Tennessee, Knoxville, Tennessee ([email protected]). This paper (No. 06-40-0773) is published with the approval of the Director of the Louisiana Agri. Expt. Sta. This paper was received for publication in January 2007. Article No. 10302. ✳Forest Products Soc. Member. ©Forest Products Society 2008. Forest Prod. J. 58(4):90-93.