Treesearch

Moving beyond the traditional focus on U.S.-Canada trade, this study employs the Spatial Durbin Model (SDM) to explore the broader dynamics of softwood lumber imports. A key contribution of this research is the recognition of spatial spillover effects, revealing the influence of third-country exporters on U.S. softwood lumber imports.The positive spatial dependence coefficient suggests that countries exporting softwood lumber to the U.S. stimulate their neighbors to follow suit, emphasizing the importance of accounting for spatial interdependencies in wood products trade analysis. These...

Building construction and operation accounts for over a third of global anthropogenic greenhouse gas (GHG) emissions and energy consumption. To determine whether more prevalent use of mass timber (MT) construction could significantly reduce environmental impacts of construction, we performed whole building life cycle assessment (WBLCA), using Athena Impact Estimator for Buildings (IE4B) software, on a series of nine multi-story residential buildings of three varying materials and heights. Three MT buildings of 18-, 12-, and 8-story heights, respectively represent IV-A, -B, and –C occupancie...

This study evaluated the effect of contact charring plus linseed oil submersion on wood chemistry and microstructure in Pinus taeda and Eucalyptus bosistoana wood specimens. Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and Raman spectroscopy analyses were performed to characterize charred wood in comparison to uncharred controls. Total lignin content increased to nearly 53% and 55% in the outer surfaces of the charred P. taedaand E. bosistoana specimens, respectively. The inner parts of the charred specimens also demonstrated increases higher than 50%...

Mass timber building construction is a natural way to mitigate climate change and prevent its associated potential global catastrophic problems. To show the mitigating impact of mass timber, an international research team led by The Nature Conversancy conducted whole-building life-cycle assessments to compare wood structures with corresponding concrete structures for 8-, 12-, and 18-story buildings, based on the 2021 International Building Code, for three regions in the United States. This report covers the set of buildings for one of those regions, specifically the set of buildings...

Naturally durable wood pre-dates preservative-treated wood and has been demonstrated to offer a suitable service life for certain applications where preservative-treated wood is not feasible. Heartwood extractives have been demonstrated to impart bio-deteriorative resistance to naturally durable wood species. These extractives are typically found in the heartwood of living trees and are produced either by the death of parenchyma cells or as the result of external stimuli. The mechanisms of natural durability are not well understood, as heartwood extractives can be extremely variable in...

Wood and plants are made of fibers that contain, in addition to cellulose, lignin and hemicelluloses. Xylan and galactoglucomannan are the dominant secondary cell wall hemicelluloses. In modern times, fibers are important materials for the biorefinery industry and for developing biocomposites. For these and other applications, the structural analysis of fibers is important, and Raman spectroscopy is among the many analytical techniques used. However, given the structural similarity between hemicelluloses and cellulose, many of their Raman contributions overlap, and the extent to which the...

Bark beetle outbreaks result in massive amounts of deadwood which are a significant carbon reservoir that can impact forest ecosystems. Additionally, bark beetle-introduced symbiotic fungi in beetle-generated deadwood can increase termite presence and feeding. This could alter decomposition rates and saproxylic communities of bark beetle-generated deadwood. However, the fate of bark beetle-generated deadwood after tree mortality has received little attention despite the possibility bark beetles could alter decomposition processes and deadwood residence times at landscape scales following...

To explore the carbon sequestration potential of hardwood forests in the eastern United States, the forest vegetation simulator (FVS) and life cycle assessment (LCA) were integrated to analyze the forest carbon dynamics for the four subregions of the eastern United States: northeast (NE), mid-Atlantic (MA), southeast (SE), and north central (NC). This study quantitatively assessed current forest management practices for timber production and their associated life-cycle environmental impacts. The system boundary was selected to be consistent with the A1 module (extraction and upstream...

Lignin is an abundant polymer in plant secondary cell walls. Prototypical lignins derive from the polymerization of monolignols (hydroxycinnamyl alcohols), mainly coniferyl and sinapyl alcohol, via combinatorial radical coupling reactions and primarily via the endwise coupling of a monomer with the phenolic end of the growing polymer. Hydroxycinnamaldehyde units have long been recognized as minor components of lignins. In plants deficient in cinnamyl alcohol dehydrogenase, the last enzyme in the monolignol biosynthesis pathway that reduces hydroxycinnamaldehydes to monolignols, chain-incorp...

Morphological characterization of microfibrillated cellulose (MFC) is critically important to process control in production and product specification for trade and product development yet is extremely difficult. This study evaluated several indirect methods for relative comparison of the morphology of lignin-free and lignin-containing ((L)MFCs). The (L)MFCs studied were produced using a commercial grinder through different passes from a dry lap bleached kraft eucalyptus pulp, a virgin mixed (maple and birch) unbleached kraft hardwood pulp, and two virgin-unbleached kraft softwood (loblolly...