Three Gram negative bacteria isolated from brownstained western hemlock were investigated for their capacity to produce hemlock brownstain. Brownstain was observed when infecting western hemlock with two bacteria. Oxygen was strongly indicated as being indespensable for the development of brownstain in infected samples. However, pH did not seem to influence the production of this stain.
The purpose of the symposium was to raise awareness of the urgent need to act to protect our forests and markets from exotic forest pests. The objectives were to: increase or improve prevention and detection measures against exotic forest pests; to make known the degree of involvement of each actor concerned; and promote exchanges and networking. The objectives were: to increase or improve prevention and detection measures against exotic forest pests; to make known the degree of involvement of each stakeholder; and to promote exchanges and networking.
Le colloque avait pour but de sensibiliser les participants à l’urgence d’agir pour protéger nos forêts et nos marchés contre les ravageurs forestiers exotiques.
Les objectifs poursuivis étaient les suivants : augmenter ou améliorer les mesures de prévention et de détection contre les ravageurs forestiers exotiques; faire connaître le degré d’implication de chaque acteur concerné; et favoriser les échanges et le réseautage.
Oriented strandboard (OSB) manufacturing technology has been advancing steadily during the past few years. Today, the industry can produce higher quality OSB at lower costs than ever before in the product's history. Research results have shown that drying costs can be reduced and strand quality can be improved through proper wood yard management, and that the production efficiency can be improved through various ways of optimizing the pressing and processing operations. OSB quality has been improved and board density has been reduced by using long and thin strands in panel face layers and relatively short and thick strands in the panel core. The press times have been reduced by using higher press temperatures and higher mat face-layer moisture contents. The degree of strand alignment has been improved by controlling the falling distance from the alignment heads to the top of mat being formed. Strands alignment has been further enhanced by arranging the alignment disc gaps in such a way so that narrower strands can be aligned through narrower gaps and directed towards core while wider strands can be aligned through wider gaps and directed towards the panel surfaces. Based on these technical advancements, OSB can be produced faster and at a lower density without sacrificing quality. Consequently, the OSB industry is in the position to improve panel quality without resorting to costly options such as increasing resin content and press time.
The absence of commercial facilities to recycle or recover value from wood treated with metal-based wood preservatives at the end of its service life is one of the most significant negative points in the generally positive life cycle analysis of treated wood. Wood treated with carbon-based preservatives (metal-free) may be far easier to recycle or recover value from since the preservatives are relatively vulnerable to thermal, chemical and biological breakdown. As a result they might be destroyed by kraft pulping, combustion or composting of treated wood. The present research evaluates the use of carbon-based preservative-treated wood in these processes.
Kraft pulps produced from wood freshly treated with recommended loadings of carbon-based preservatives contained significant quantities of didecyldimethylammonium carbonate (DDAcarbonate), propiconazole and tebuconazole. However, lower preservative concentration in the wood and intensive pulping may be able to produce pulps without detectable preservatives. The azoles were also detected in significant quantities in the black liquor (DDAcarbonate was not analysed in black liquor).
No azoles were found in the ash produced from combustion, but significant quantities were detected in the filtered smoke. DDAcarbonate was not detected in the filtered smoke. Analysis of DDAcarbonate in ash was inconclusive.
A composting experiment has been set up and is in progress. Data on preservative breakdown during composting is expected next year.
As a result of its potential as an added-value, environmentally acceptable, high performance wood product, borate-treated lumber has attracted the interest of the Canadian forest products industry (Byrne 1990). One of the potential markets for borate-treated wood in Europe and North America is millwork. Currently millwork manufacturers use light organic solvent preservatives to provide durability to their products but there are a number of reasons why this situation may change in the near future. There are increasing pressures on uncontrolled emission of volatile organic solvents from treated wood and public concerns regarding some of the active ingredients now in use (Orsler and Holland 1993). The use of borate-treated wood eliminates both of these problems and may provide some additional advantages by eliminating batch processing in the manufacture of joinery. The one factor which is likely to have the greatest impact on the performance of borate-treated millwork is the mobility of the boron. Borate-treated wood is currently approved for use in exterior exposure in New Zealand provided it has a three-coat paint finish. Nevertheless there is concern outside New Zealand that redistribution of boron within the treated wood could lead to localized depletion and decay. An L-joint test of borate-treated wood was set up by Forintek to determine whether preservative depletion and subsequent decay is likely to be a problem. This report describes the performance results of this trial after six years and compares borate content of the L-joints initially and after five years exposure.
To better understand the role extractives play in western red cedar’s decay resistance, commonly detected but unknown extractives need to be identified and evaluated for their potential contribution to natural durability. A new liquid chromatography/mass spectrometry (LC/MS) method for separating extractives from western red cedar has been developed. Mass spectral detection provides useful structural information that gives increased confidence in peak identifications and helps to identify unknown peaks. Using LC/MS data, combined with data from UV and NMR spectroscopy, unknown compound J commonly found in many samples of WRC we have analysed, was identified as alpha-thujaplicin. This was known to be a major extractive in eastern white cedar but was considered to be a negligible component of WRC. Its potential contribution to the durability of WRC has not been considered in previous work attempting to correlate durability to specific extractives.
The objectives of the project are to determine the major source of bluestain fungi and determine the mechanisms of their dispersion, and to determine the biology and weak points of pests that may be expoited to control them.
This article is the fourth in a series presenting different aspects of aspects of research conducted at the Canadian Service (CFS) and FPInnovations and FPInnovations in the area of forest forest biomass.
Cet article est le quatrième d’une série présentant différents aspects de la recherche effectuée au Service canadien des forêts (SCF) et chez FPInnovations dans le domaine de la biomasse forestière.
Forest biomass can be used to produce biofuels in solid, liquid and gaseous form. This article focuses on solid fuels and the feeding of cogeneration plants and institutional boiler rooms. Liquid and gaseous fuels will be the subject of future articles in this series.
La biomasse forestière permet de produire des biocombustibles sous forme solide, liquide et gazeuse. Cet article porte sur les combustibles solides et l’alimentation des centrales de cogénération et des chaufferies institutionnelles. Les combustibles liquides et gazeux feront l’objet des prochains articles de cette série.
Canada is part of a global effort to replace the use of fossil fuels, which are major emitters of greenhouse gases, with cleaner alternatives. The Canadian Wood Fibre Centre (CWFC) is pursuing research in this area by looking at forest biomass as a substitute for petroleum products. Its research focuses on forest biomass supply sources (quantity available, location, harvesting costs, environmental impacts) and also on the characterization of wood fibre in order to develop new products for various uses.
Le Canada s’inscrit dans le déploiement d’efforts à l’échelle mondiale en vue de remplacer l’utilisation de combustibles fossiles, grands émetteurs de gaz à effet de serre, par des alternatives moins polluantes. Le Centre canadien sur la fibre de bois (CCFB) poursuit des recherches en ce sens en s’intéressant à la biomasse forestière comme substitut aux produits pétroliers. Ses recherches portent sur les sources d’approvisionnement en biomasse forestière (la quantité disponible, la localisation, les coûts de récolte, les impacts environnementaux) et aussi sur la caractérisation de la fibre de bois afin de développer de nouveaux produits qui seront utilisés à diverses fins.