Treesearch

Brown-rot fungi lack many enzymes associated with complete wood degradation, such as lignin-attacking peroxidases, and have developed alternative mechanisms for rapid wood breakdown. To identify the effects of culture conditions and wood substrates on gene expression, we grew Fibroporia radiculosa in submerged cultures containing Wiley milled wood (5 days) and solid wood wafers (30 days), using aspen, pine, and spruce as a substrate. The comparative analysis revealed that wood species had a limited effect on the transcriptome: <3% of genes were differentially expressed between different...

This work evaluates wheat straw, switchgrass, and hemp hurd as potential alternatives for producing dissolving pulp using sulfur dioxide (SO2)-ethanol-water (SEW) pulping. The SEW process is described in detail for wheat straw, and the best pulping conditions for this feedstock were 130 °C, 4 h, and 10% SO2 concentration, comprised in a sulfur-ethanol-water ratio of 10-45-45. This resulted in a viscose-grade pulp with 93% α-cellulose, 2.0% hemicelluloses, <0.1% lignin, 0.2% ash content, and a viscosity of 4.7 cP. The best pulping conditions for wheat straw were applied to switchgrass and...

Waterlogged wood conservation is a complex and challenging task. Detailed knowledge about the interactions between the applied chemicals and wood is necessary to ensure the effective and safe conservation of wooden artifacts. The present research aims to determine the mechanism of dimensional stabilization of archeological wood by organosilicon compounds using the combination of synchrotron-based X-ray fluorescence microscopy (XFM) and nanoindentation. Archeological oak wood was treated with methyltrimethoxysilane, (3-mercaptopropyl) trimethoxysilane, or 1,3-bis-[(diethylamino)-3-(propoxy)p...

In this study, we investigated the impact on surface topography and micro-mechanical properties of polyvinyl alcohol (PVA) thin films when loaded with hardwood-derived biocarbon particles (BCP). The PVA/BCP composites were prepared with the conventional film casting method, after varying BCP concentrations of 6, 8, 10, 12, and 20 wt% were added to the PVA solution. Atomic force microscopy (AFM) investigations and nanoindentation tests were performed. The average roughness of the thin films increased with the increase in BCP content. The alternation between dark and light patterns observed...

The use of wood in construction requires knowledge of the mechanical properties and the particularities that wood presents in comparison with other materials used for structural purposes such as steel, concrete, brick, or stone. The introduction mentions the environmental advantages that justify the use of wood today. The orthotropy of wood is one of the differentiating characteristics that must be taken into account when studying its behaviour. The determination of the properties of wood is then addressed from a historical perspective and the differentiation is made between the properties...

Disruption of photosynthesis and carbon transport due to damage to the tree crown and stem cambial cells, respectively, can cause tree mortality. It has recently been proposed that fire-induced dysfunction of xylem plays an important role in tree mortality. Here, we simultaneously tested the impact of a lethal fire dose on nonstructural carbohydrates (NSCs) and xylem hydraulics in Pinus ponderosa saplings. Saplings were burned with a known lethal fire dose. Nonstructural carbohydrates were assessed in needles, main stems, roots and whole plants, and xylem hydraulic conductivity was...

Wildfires represent major ecological disturbances, burning 2–3% of Earth’s terrestrial area each year with sometimes drastic effects above and belowground. Soil bacteria offer an ideal, yet understudied system within which to explore fundamental principles of fire ecology. To understand how wildfires restructure soil bacterial communities and alter their functioning, we sought to translate aboveground fire ecology to belowground systems by determining which microbial traits are important post-fire and whether changes in bacterial communities affect carbon cycling. We employed an uncommon...

Due to the increasingly widespread water pollutants and the high cost of treatment methods, there is a demand for new, inexpensive, renewable, and biodegradable adsorbent materials for the purification of wastewater contaminants. In this study, a new biocomposite aerogel (Amf-CNF/LS) was prepared using a chemically cross-linking method between the amino-functionalized cellulose nanofibers (Amf-CNF) and lignosulfonates (LS). The physical and chemical properties of the prepared aerogel were investigated using several techniques including elemental analysis, scanning electron microscopy...

Lignin is an abundant and complex plant polymer that may limit litter decomposition, yet lignin is sometimes a minor constituent of soil organic carbon (SOC). Accounting for diversity in soil characteristics might reconcile this apparent contradiction. Tracking decomposition of a lignin/litter mixture and SOC across different North American mineral soils using lab and field incubations, here we show that cumulative lignin decomposition varies 18-fold among soils and is strongly correlated with bulk litter decomposition, but not SOC decomposition. Climate legacy predicts decomposition in...

Round timber and wood products are measured, sorted, and graded at different stages in the wood-value chain starting already at the stem level in the forest. This chapter gives an overview of grading methodologies and techhniques for the measurement and grading of round timber, sawn timber, veneer, and wood-panel products. The section concerning round timber focuses on the grading and sorting of logs for sawmill and veneer production. For sawn timber, visual and strength grading are discussed, for both the European and the North American markets. Techniques for measurement and process...