Treesearch

The USDA Forest Service, Forest Products Laboratory, was asked to inspect the timber frame that supports the USS Cairo, a historic civil war ship at the Vicksburg National Military Park in Vicksburg, Mississippi. Because the display of the historic ship and its support structure are located outdoors and are exposed to the elements, there is concern about deterioration from decay of the support structure. This report summarizes the results obtained from the inspection and assessment. It includes a summary of observations, wood species identification, and recommendations. The timber support...

Lignin possesses diverse bioactivities due to its unique physicochemical structure. This study investigates the structural-bioactivity relationships of lignin derived from maleic acid hydrotropic fractionation (MAHF) of two types of herbaceous biomass. The results indicated that lignin with higher phenolic hydroxyl (-OH) content (up to 2.0 mmol/g) and carboxyl (-COOH) groups (up to 0.89 mmol/g) exhibited significantly enhanced antioxidant activity. The highest antioxidant of MAHF lignin (MAHL) reached 98 % for scavenging DPPH (2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl) at 0.56 mg/mL....

We assessed the relative capacity of key global wood baskets in Latin America and Asia to determine their ability to meet increases in demands for pulp and paper, or to grow trees to store forest carbon. Drawing from the Trillion Trees proposal in 2020, a central aim of the research was to determine if a single country could plant an additional 10 million hectares (ha) by 2030. We analyzed secondary information from publicly available literature about the forest sector, forest plantations, and forest restoration in various countries. We screened land use types from the FAO data base to...

In this study, the effects of adhesives on the bonding performance of both southern yellow pine (SYP) and red maple plywood were investigated. Phenol–formaldehyde (PF), polymeric diphenylmethane diisocyanate (pMDI), phenol–resorcinol–formaldehyde (PRF), and polyurethane (PUR) were evaluated. This allowed us to understand the difference between thermosetting and cold-setting adhesives, as well as phenolic and isocyanate ones. Three-ply plywoods were fabricated using red maple veneers (Acer rubrum) for hardwood plywood specimens and using SYP (Pinus spp.) for softwood plywood specimens. The...

Addressing climate change is a global priority. Life-cycle assessment (LCA) quantifies the carbon footprint of products and can provide strategies for climate change mitigation. This novel study analyzed the energy consumption of softwood sawmills and used attributional LCA to estimate cradle-to-gate environmental impacts of softwood lumber manufactured in California. Using a representative sample size, 16 California sawmills (capturing 88% of lumber production) were surveyed. Sawmills’ energy consumption was characterized and evaluated by fuel type and on-site energy generation for annual...

This case study conducted a cradle-to-gate life cycle assessment (LCA) on the production of hardwood lumber in New Brunswick, Canada, evaluating the environmental impacts from raw material extraction to the point where lumber exited the mill as rough green lumber, the primary input for manufacturing pallets and railway ties. Data on annual production, material flow, and energy use for harvesting and sawmilling were gathered through survey questionnaires and on-site visits. The life cycle inventory (LCI) was developed in SimaPro software, the life cycle impact assessment (LCIA) was conducted...

The Forest Products Laboratory NONPAR procedure is explained in mathematical detail and demonstrated with examples. The procedure for constructing confidence intervals is updated from a previous version. Tables listing order statistics representing lower tolerance limits and confidence intervals for the 5th percentile are exhibited for sample sizes up to 5,000.

Soil respiration plays a key role in regulating ecosystem CO2 emissions and atmospheric concentrations. However, because it is highly sensitive to the environment and has large temporal and spatial variability, its contribution to the global carbon cycle remains highly uncertain. Recent advances in ecosystem process models have uniquely constrained soil respiration rates, largely based on results from tracing ecosystem CO2 losses using radioisotope and stable isotope methods. However, the computational requirements of process-based models at large scales are costly, limiting their applicati...

Air leakage is one of the critical moisture sources that may compromise the structural integrity and air quality of wood-frame buildings. The present study investigates air leakage through typical North American oriented strand board (OSB) sheathing using a one-of-a-kind analytical chamber, the CARWASh, which is designed to generate temperature- and humidity-controlled outdoor and indoor conditions for the evaluation of water management performance and moisture dynamics of exterior wall assemblies. We establish a baseline estimate for air leakage through OSB sheathing in full-scale...

Surface checks, cracks, and splits can occur in wood when it dries out too rapidly. Wood expands and contracts with changes in moisture content in the hygroscopic range. Spatial differences in wood moisture content cause internal stresses, and cracks form when these moisture-induced stresses exceed the tensile strength of the material. Large moisture gradients may occur in mass timber products, such as glue-laminated timber (glulam) and cross-laminated timber (CLT), at multiple points during and after exposure to moisture during the construction process, followed by abrupt changes in the...