The wood preservative chromated copper arsenate (CCA) contains hexavalent chromium [Cr(VI)] and the conversion of Cr(VI) to trivalent chromium [Cr(III)] drives fixation of the treatment chemicals to the wood fibers. Since the toxicity of Cr depends on its valence state, an assessment of the Cr species occurring in CCA-treated wood, as well as leachates and ashes from CCA-treated wood, is helpfu...

hemicellulose of southern yellow pine wood spices was extracted by pressurized hot water at three different temperatures: 140°c, 155°c and 170°c. compounding with pp (polypropylene) was performed by extrusion after preparing wood flour and sieving to determine its mesh size. the ratio of wood to polymer was 50:50 based on oven-dry weight of wood flour. all extraction treatments and control samp...

The papermaking properties of 22 pure and hybrid poplars are being evaluated in an on-going investigation. Twenty of the poplars were harvested after 7.5 years from three different sites in the Midwestern and North Central US. The other 2 poplars survived at only two of three sites (64 total samples). The Crandon hybrid had the highest growth rate (t ha 1 y ) and wood density (both averaged acr...

Forest structural heterogeneity due to species composition, spatial relationships and tree size are widely studied patterns in forest systems, but their impacts on tree function are not as well documented. The objective of this study was to examine how stand composition, tree proximity relationships and tree size influence the leaf functional traits of aspen, an early successional species, and ...

Trembling aspen (Populus tremuloides Michx.) generally grows as clones in which stems, ranging from many thousands to only a few, are interconnected by a common root system. When clones are very large, in one recorded case involving about 47␣ 000 stems joined together over a 43 ha area, aspen becomes a candidate for earth’s most massive and oldest organism. Recent analyses suggest that aspen cl...

Wood formation is a fundamental biological process with significant economic interest. While lignin biosynthesis is currently relatively well understood, the pathways leading to the synthesis of the key structural carbohydrates in wood fibers remain obscure. We have used a functional genomics approach to identify enzymes involved in carbohydrate biosynthesis and remodeling during xylem developm...

hfunlclpal and papermill wastewater sludges were ipplled to conifer and hardwood forests growing on sand soils (Entic Haplorthods, Spodic Udipsamments, and Alfic Haplorthods), In northwestern Lower Michigan where annual preclpltatio~~ averaged 765 mm/y, to Investigate the Impact of sludge on nitrate-N concentntlons In soil water and groundwater. During the first growing season after treatment, ...

Wood-inhabiting bacteria are associated with wood decay and may have an indirect influence on the decay process. Bacteria are able to affect wood permeability, attack wood structure, or work synergistically with other bacteria and soft-rot fungi to predispose wood to fungal attack. Bacteria that can inhabit chemically treated wood are recognized. The natural ability of certain bacterial genera ...

New alternative wood preservatives contain higher levels of copper (Cu) which can promote aquatic toxicity in natural water systems. Earlier work focused on evaluating toxicity using laboratory generated leaching solutions. In this study, the impact on preservative leaching and aquatic toxicity from treated wood products was evaluated using natural surface waters including waters from two river...

1 Corresponding author: [email protected]; 715-346-4098 2 [email protected]; 541-737-3056 ABSTRACT: Aspen (Populus tremuloides) stands inside and outside Yellowstone National Park (YNP), Wyoming, USA, were compared to test whether the lack of overstory aspen recruitment observed in YNP extended to winter ranges of elk (Cervus elaphus) in adjacent national forests. Remote sensing and fi...