Treesearch

Sphaeroma terebrans Bate is a widespread estuarine, wood-boring, isopod found in red mangrove (Rhizophora mangle) forests of tropical and subtropical estuarine waters. Because it causes extensive damage to man-made structures in marine coastal zones and is resistant to common methods of wood preservation it is important to understand fully how S. terebrans uses the wood into which it bores. Previous studies indicate that S. terebrans is primarily a filler-feeder and does not utilize bored wood as a nutritive substrate. However, laboratory feeding data obtained in this study indicate that...

Three stilbenes, pinosylvin (PS), pinosylvin monomethyl ether (PSM) and pinosylvin dimethyl ether (PSD), were extracted from white spruce (Picea glauca), jack pine (Pinus banksiana), and red pine (Pinus resinosa) pine cones, and their structures were confirmed by spectroscopic and chromatographic (HPLC, GC/MS, NMR and FTIR) analysis. PS, PSM, PSD or a 1:1:1 mixture of these stilbenes at concentrations of 0.1% and 1.0% were examined for their fungal inhibitory activity by two bioassay methods. Growth of white-rot fungi (Trametes versicolor and Phanerochaete chrysosporium), and brown-rot...

Ultrasonic inspection of lumber has been under investigation for over 20 years, with little commercial impact. Recently, the USDA Forest Products Laboratory (FPL) developed ultrasound-based scanning technology to examine both green and dried lumber. In green lumber, the bacterial infection called wetwood (a significant source of degradation in oak at the kiln-drying stage) was found with high accuracy using time-of-flight techniques. A similar approach was used to locate checking and honeycombing in dried lumber, defects that are often not apparent by external visual inspection. This...

The unmitigated pest risk potential for the importation of Pinus and Abies logs from all states of Mexico into the United States was assessed by estimating the probability and consequences of establishment of representative insects and pathogens of concern. Twenty-two individual pest risk assessments were prepared for Pinus logs, twelve dealing with insects and ten with pathogens. Six individual assessments were prepared for Abies logs. The selected organisms were representative examples of insects and pathogens found on the bark, in the bark, and in the wood of Pinus or Abies logs. Among...

The system of model building codes and voluntary product standards used in the United States for structural lumber and engineered wood products can appear complicated and confusing to those introduced to it for the first time. This paper is a discussion of the various types of structural wood products commonly used in U.S. residential and commercial construction and the system of building codes and product and performance standards that help regulate the quality and use of these products.

In laboratory experiments, Douglas-fir wood blocks that were treated with copper- based wood preservatives were challenged with two wood decay fungi known to be tolerant of copper. Factors influencing the amount of decay, as determined by loss of weight in the test blocks, were preservative, then fungus. Within those combinations, the relative importance of preservative retention, block thickness, or leaching depended upon the specific pairings of preservative and fungus. Low retention levels of some preservatives stimulated decay by Wolfiporia cocos but not Postia placenta. We conclude...

Kenaf-based thermoplastic composites were developed and evaluated in this study. The kenaf stems were collected from farms in central Illinois. The kenaf fibers were blended with commercial virgin plastic or polypropylene and with recycled plastics or low-cost polyethylene in form of post-consumer film wastes and shrink wraps. Investigations on the fiber properties and chemical compositions of kenaf stems showed that they can be viably utilized as substitute for wood flour fillers. Manufacturing tests conducted at the U.S. Forest Products Laboratory showed that kenaf stems can be used as...

Xylaria species are common endophytes in tropical plants. It is not known, however, whether transmission of Xylaria occurs horizontally or vertically, whether individual Xylaria strains have wide host ranges or are host-specific, or how they are dispersed. We compared frequency of Xylaria endophytes in leaves and seeds of two tree species in Puerto Rico, Casuarina equisetifolia (Australian pine) and Manilkara bidentata (ausubo). These trees were chosen because they differ markedly in morphology, habitat, distribution, and origin. In C. equisetifolia Xylaria was significantly more frequent...

Most of the approximately 25 to 30 million tons of industrial wood waste generated in the United States per year is burned for energy and/or landfilled. In this study, kraft pulp from industrial wood waste was evaluated and compared with softwood (loblolly pine, Douglas-fir) and hardwood (aspen) pulp. Pulp bleachability was also evaluated. Compared to loblolly pine pulp, industrial wood waste pulp needed less cooking time to achieve the same kappa number and achieved a higher pulp yield for a similar kappa number. Industrial wood waste pulp was more effectively bleached than loblolly pine...

Ten single-spore isolates each of Armillaria sinapina, A. cepistipes, and North American biological species (NABS)X and XI were paired in all combinations. A second set of ten single-spore isolates of each species was likewise paired. Each pairing was duplicated for a total of 3280 pairs. Using the standard morphological criteria (e.g., fluffy, crustose) to assess the pairings, A. sinapina exhibited the following compatibility levels: 68% with itself, 5.5% with A. cepistipes, 3.5% with NABS X, and 5% with NABS XI, respectively. Armillaria cepistipes was rated 53%, 6.5%, and 57% compatible...