Treesearch

The Forest Products Laboratory (FPL) has provided equilibrium moisture content (EMC) values of wood for given temperature and relative humidity (RH) conditions in various forms over the course of its history, primarily for practical purposes related to drying lumber and controlling moisture content. The FPL EMC data have been widely cited and reprinted, not only in literature of a practical nature such as the Wood Handbook, but also in textbooks and journal articles as a basis for scientific discourse on the thermodynamics of water vapor sorption in wood and evaluation of physical models....

Wood specific gravity (SG) is widely employed by ecologists as a key variable in estimates of biomass. When it is important to have nondestructive methods for sampling wood for SG measurements, cores are extracted with an increment borer. While boring is a relatively difficult task even at breast height sampling, it is impossible at ground level and arduous at heights above a couple of meters. Therefore, if a nondestructive estimate of the biomass of a whole stem is required, the variation of SG with height must be known. Here we look at the SG variation with height of five tropical trees,...

Not every saw log is straight and cylindrical in shape. In fact, logs are commonly out-of-round, tapered, or crooked, and often a combination of these shapes. Sawmill operators employ every means to recover as much yield as possible from each log. Yield recovery can be the difference between a profitable and a nonprofitable log. There are opportunities for improving yield in out-of-shape hardwood saw logs while still maintaining lumber quality.

Advances in wood protection based on nanotechnology are being developed to improve resistance of wood products to biodeterioration, reduce environmental impacts from chemical leaching and resist UV degradation of in-service wood. A number of different approaches have been explored. First, the nanometals zinc oxide and copper oxide were evaluated as preservative treatments for wood. Both nanoZnO and nanoCuO were leach resistant. NanoZnO also inhibited decay fungi, acted as a termite toxicant, and provided photostability of wood against UV degradation. Second, self-assembling nanopolymer...

From 2005–10, the USDA Forest Service’s Woody Biomass Utilization Grant program provided grants for equipment acquisition and technical assistance to rural businesses and other entities. These grants were intended to encourage enterprise development, address market barriers to biomass utilization (ranging from small-diameter sawtimber to chips and logging residues), and decrease forest restoration costs by adding value to biomass products. At the request of the USDA Forest Service – State and Private Forestry’s Forest Products Technology Marketing Unit at the Forest Products Laboratory, we...

The reinforcement potential of cellulose nanocrystal (CNC) additions on an idealized 2-dirmensional (2-D) fiber network structure consisting of micron sized fiber elements was investigated. The reinforcement mechanism considered in this study was through the stiffening of the micron sized fiber elements via a CNC-epoxy coating. A hierarchical analytical modeling approach was used to estimate the elastic properties spanning three different structural features; i) micromechanics for CNC-epoxy properties, ii) laminate theory for fiber elements coated with CNC-epoxy, and iii) a 2-D network...

Biological invasions resulting from international trade can cause major environmental and economic impacts. Propagule pressure is perhaps the most important factor influencing establishment, although actual arrival rates of species are rarely recorded. Furthermore, the pool of potential invaders includes many species that vary in their arrival rate and establishment potential. Therefore, we stress that it is essential to consider the size and composition of species pools arriving from source regions when estimating probabilities of establishment and effects of pathway infestation rates. To...

Measurement of particle-size distribution (PSD) of soil with large-sized particles (e.g., 25.4 mm diameter) requires a large sample and numerous particle-size analyses (PSAs). A new method is needed that would reduce time, effort, and cost for PSAs of the soil and aggregate material with large-sized particles. We evaluated a nested method for sampling and PSA by comparing it with the methods that follow the American Association of State Highway and Transportation Officials (AASHTO) standard T88-00 and the American Society for Testing and Materials (ASTM) standard D422-63. Using 33 forest...

The structure of lignin after dilute phosphoric acid plus steam explosion pretreatment process of sugarcane bagasse in a pilot scale and the effect of the lignin extracted by ethanol on subsequent cellulose hydrolysis were investigated. The lignin structural changes caused by pretreatment were identified using advanced nondestructive techniques such as gel permeation chromatography (GPC), quantitative 13C, and 2-D nuclear magnetic resonance (NMR). The structural analysis revealed that ethanol extractable lignin preserved basic lignin structure, but had relatively lower amount of β-O-4...

Conservation efforts are most effective when we have complete demographic information for a species of concern. Nevertheless, fundamental gaps in our knowledge of demography still exist for many taxa. For passerine birds, the period of time directly after young birds leave the nest and before they disperse and/or migrate (i.e., the post-fledging period) remains an understudied life stage. We reviewed the literature on survival of passerine birds during the post-fledging period to synthesize current knowledge on survival rates and the factors affecting these rates, and conducted a sensitivit...