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Columns::October 1, 2001
Annual Russell Symposium focuses on international security
UGA musical groups celebrate Spirit of America’
New portrait of Rogers will be added to presidential collection
Open enrollment period begins Oct. 15 for insurance plans
Remediation process begins over site of former UGA landfill
A message to the university community
Campus Closeup
Biological and ag engineering head will direct UGA faculty of engineering
College of Pharmacy names assistant dean
Kudos
And the beat goes on. . .
Campus News
Woodwork
UGA researchers conduct studies to determine strength characterstics of timber
By Helen Fosgate
hfosgate@smokey.forestry.uga.edu
The demand has never been greater for Southern yellow pine, a primary wood used in the construction of homes, decks and
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| UGA professor of quantitative forest management Dick Daniels (left) and Alex Clark, a wood scientist with the USDA Forest Service, are co-directing the Wood Quality Consortium. |
many engineered wood products like plywood. And while forest products companies have more incentive than ever to increase production and harvest earlier, the pressure to push wood to market is having profound effects, both in the industry and marketplace.
“The trend toward fast-growing plantations and shorter rotations means a higher ratio of juvenile wood on the market,” says Dick Daniels, professor of quantitative forest management in UGA’s Warnell School of Forest Resources. “Juvenile wood may be fine for some paper products, but it’s not best for building products, where strength is important.”
Daniels and Alex Clark, a wood scientist with the USDA Forest Service, co-direct UGA’s Wood Quality Consortium, a research cooperative supported by nine forest products companies. Consortium researchers are conducting studies to determine the strength characteristics of wood and, more importantly, the most appropriate uses for wood of varying ages.
“Even in engineered wood products, a degree of natural strength and stiffness has to be there or glue must be substituted, and that’s expensive,” says Clark, who oversees the wood-testing part of the research in his lab at the Southern Research Station Forest Sciences Lab on campus. “The main thing is to be sure the trees we’re growing now can provide what the consumer needs in 20 years. We don’t want to push trees so much in the growing phase that we experience strength failures in the wood down the road.”
Daniels says while the industry isn’t yet producing custom-grown pines for specific uses, it almost certainly will in the future. In the meantime, industry leaders are well aware of their challenge: Produce copious amounts of high-quality wood--and fast.
No matter how you slice it, wood quality begins in the woods and fields. Site preparation, cultivation practices like fertilization and weed control, growth rate and seedling genetics all affect the quality and strength of finished wood products. But it’s not that simple. Wood quality properties vary widely, not only between trees of different age groups, but within stands, regions and even individual trees.
“Our job initially is to characterize how the properties of wood and lumber relate back to cultivation practices,” says Clark.
Specialized machines in the lab help researchers measure the growth rate and density of early and latewood within the annual rings, as well as wood strength, stiffness, toughness and dimensional stability. Latewood is the darker portion of the annual ring in Southern pine. Added in late summer, latewood is denser, thicker and stronger than the lighter-colored rings pines grow early in the season, and it adds strength and stiffness to wood. Researchers relate the proportion of latewood in the annual ring, wood density, fiber length and wall thickness with wood properties of trees grown under different cultural conditions.
“We’re developing predictive models for quality just as we have for quantity,” says Daniels. “For example, if we know the growing conditions, including location, age, fertilization and weed-control regimes, we should be able to predict wood-quality characteristics, such as density, moisture content, stiffness, strength and dimensional stability.”
Daniels says test plantations are available to sample, thanks to the work of researchers in cooperatives across the South, including the Warnell School’s own Plantation Management Research Cooperative and the Consortium for Advanced Pine Plantation Productivity. Researchers at the Plantation Management Research Cooperative have been conducting intensive pine-production studies in Georgia and surrounding states for 25 years. They have shown it is possible to double--even triple--fiber yields, although intensive methods produce more juvenile wood.
Daniels and Clark also are able to draw on the work of researchers at Auburn, the University of Florida, Virginia Tech and North Carolina State, partners in the Wood Quality Consortium.
“Over the past decade, we’ve made tremendous gains at improving yields,” says Daniels. “The next step in our quest for improved production will focus on quality. Initially, we’ll look only at pines, but as our work progresses, we hope to include hardwoods as well.”
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