Improved Wood Properties from Plantation Forestry, 1994 Process & Product Quality Conference Proceedings

Initial efforts, in the 1950s and 1960s, in tree improvement programs in the southern United States selected for average or above average wood specific gravity. Since that time, as we have progressed from first to second and third generation seed orchards of the southern pines (primarily loblolly and slash pines), breeding for wood properties has received scant attention. The emphasis has primarily been on tree growth, form and pest resistance. That inattention aside, improvements in wood density have been achieved from the uniformity of plantation grown trees compared to uneven-aged trees of natural stands. <>

Plantation forestry outside the United States, primarily of exotic species of pines, eucalypts, acacias and gmelina, exhibits the benefits that can be obtained from wood uniformity. Such plantations are either thinned or clear density and other wood properties. In clonal forestry, as is being widely practiced with eucalyptus, pulp mill runs are being made on single clones. Even with the same average wood density, pulp yields and other pulp and paper properties are significantly different from one clone to another, resulting in large financial gains. Similar potential gains can be obtained from pines and hardwoods in the U.S. South from use of molecular genetics and asexual propagation.