Western larch (Larix occidentalis Nutt.) is one of three native Larix species in North America, besides subalpine larch (Larix lyallii Parl.) and tamarack (Larix laricina (Du Roi) K. Koch). It easily reaches 50 m in total height. High wood density and strength usually characterize its wood. In British Columbia, western larch represents a minor component of the provincial timber supply. Due to extensive western larch plantations in southeastern British Columbia it promises to become an important wood species in this region. Throughout most of western larches' natural range, existing stands originated from natural regeneration following wildfires, and are often overstocked. Therefore, early reductions of stand densities by precommercial thinning became an important management tool to establish stabilized stands and to concentrate stand growth potential on fewer vigorous, well-formed trees. This process of maximizing total stand value rather than maximizing yield can be completed by later commercial thinning and artificial pruning. The intent of this study was to provide basic information on the relationship between tree spacing and the two major wood quality parameters wood density and branch size to support stand management decisions. From four 43/45-year-old western larch experimental stands in northwest Montana, 618 sample trees were chosen representing different stocking levels ranging from 270 to 6700 trees per hectare. From two pith-to-bark cores, taken at breast height for each tree, density profiles were obtained using Forintek's x-ray densitometer. Additionally, the largest branch diameters in 4 m-stem height and below in four selected plots on three sites were measured and analysed. The sample trees showed a strong relationship between width of spacing and tree height and diameter breast height. As expected, trees in the widest spaced plots grew the fastest. Despite large differences in diameter growth, no significant differences in average wood density occurred between spacings. A second moderate thinning on the best sites clearly showed that enhancing the wood density of western larch is possible. As expected the branch diameter increases nearly linearly with the width of the initial spacing in western larch stands. But for the most valuable part of the tree, the branch sizes do not exceed 20 mm even when a wide spacing as 4.6 by 4.6 m is applied. The overall high relative wood density level of about 0.52, which is the highest average wood density of the commercial softwood in North America, and a reasonable knot size confirm that western larch from managed stands remains a valuable tree species in future markets.
Rapport de mission : Allemagne; Exposition Fensterbau, 18-20 février 1999 (Stuttgart) et visites industrielles (Rosenheim et Schnelldorf) : opportunités pour l'industrie de la transformation du bois dans le secteur des portes extérieures et fenêtres au Québec; 16 au 23 février 1999
A field test of untreated and preservative-treated round fence posts has been ongoing at Petawawa, Ontario since 1937. Service life data on twenty eastern Canadian wood species was developed. In addition, treatments by a variety of pressure and non-pressure processes with waterborne and oilborne preservatives were tested. Thermal immersion in creosote was the most effective non-pressure method used. Brush treatments and cold soaking proved to be ineffective for long-term protection from decay. Pressure treatment utilizing standard waterborne (CCA and ACA) and oilborne (creosote, pentachlorophenol, and copper naphthenate) provided excellent protection from decay.
Samples of end-matched preservative-treated dimensional lumber have been exposed in ground contact for 10 years at Forintek's two test plots in Ontario. At Kincardine, the site supports a colony of the Eastern subterranean termite, Reticulitermes flavipes (Kollar); at Petawawa, there is no termite activity. While decay is somewhat more pronounced at Kincardine, the major difference between the sites is due to the presence or absence of termite activity. Termites are a much more serious threat than decay for treated wood with shallow preservative penetration.
In the 3-year rotation of subject matter for the reports of the "Durability of Wood" project, attention has again turned to treated commodities. In these tests, we evaluate not only the efficacy of the wood preservative, but also the effect on performance of the quality of treatment that can be achieved with Canadian wood species. The collection of long-term performance data takes time and it is impossible to predict questions about standards for which answers will be needed in 10 or 20 years' time. Consequently, Forintek has maintained a comprehensive field-testing program covering a wide range of commodities, wood species, preservatives and treatment methods. The reports in this compilation cover decking, finger-jointed lumber above ground, shakes, millwork, fence posts, lumber in a termite area and needle-incised lumber in an accelerated ground contact test.
Softwoods - Preservatives
Glued joints - Finger - Preservation
Preservatives - Chromated copper arsenate (CCA)
Preservatives - Penetration
Preservation - Durability
Decking - Preservation
Shingles - Preservation
Thuja plicata - Shingles
Shingles - Durability
Preservatives - Ammoniacal copper arsenate (ACA)
Posts - Preservation
Preservation - Incising - Tests
Picea - Preservation
Pinus contorta Dougl. var. latifolia - Preservation
The objective of this study is to compare wood product attributes demanded to those that can be profitably and competitively supplied to the Japanese market by the Canadian primary and secondary wood products sector. Specifically, this includes providing market research and an international trade-flow analysis to highlight areas of competitive advantage for the Canadian primary and secondary wood products sectors.
The study has been broken down into three components: the Attribute Analysis, the Competitor Analysis, and the Linkage Analysis. The first of these has been completed and reported in seven publications as follows:
Japan's Value Added Market: Wood Product Attributes and Competition:
Attribute Analysis: Introduction and Methodology
Attribute Analysis: Building Systems
Attribute Analysis: Wood Structural Members
Attribute Analysis: Engineered Structural Products
Attribute Analysis: Interior Finish
Attribute Analysis: Wood Furniture
Attribute Analysis: Outdoor Furnishings and Decking.
The second component of the study, the Competitor Analysis, has been ongoing since the beginning of the project, and the first of two reports was released:
Japan's Value Added Market: Wood Product Attributes and Competition:
Competitor Analysis One.
Competitor Analysis One focused on the methodology employed in reconciling and organizing wood products trade data and subsequent trade-flow modelling. This report also offers an appendix of all softwood lumber trade detail used in the model, both in volume of and in unit value, from 1991 to 1997. Japan's Value Added Market: Wood Product Attributes and Competition: Competitor Analysis Two, continues with the inclusion of categories of softwood logs and structural and non-structural panel products. Further, Competitor Analysis two offers base-line trade forecasts for all wood product categories investigated for the years 2002 and 2007, as well an illustration of "what-if" scenarios against these forecasts. This report highlights this information.
The third component of the study, the Linkage Analysis, was not scheduled for commencement in this fiscal year. However, with the addition of a new researcher, this portion of the study is ahead of schedule, with the methodology for the analysis developed. This methodology is highlighted in this report.
Japan's Value Added Market: Wood Product Attributes and Competition: Linkage Analysis is expected for release in the summer of 1999.
The project Decision Aids for Durable Wood Construction underwent a major review with the hiring of a new project leader (O'Connor) in September 1998. In consultation with the project liaisons, the work on this project since its start-up in 1993 was examined, the primary task of developing a computer-based tool for the building industry was reconsidered, the context of worldwide research into building envelope moisture failures was reviewed, and a revised project plan was proposed.
Decision Aids was a self-contained project for its first three years, with efforts concentrated on knowledge acquisition, expert system experimentation and other foundation work for development of a computer tool. With a rise of interest in building envelope moisture failures across North America and elsewhere, Decision Aids activity shifted into a mode that was reactive to projects and events external to Forintek. This was necessary due to the level of effort external agencies, media and research labs were devoting to the topic. In particular, where the actions of outsiders began to have an influence on wood in construction, we found it critical to participate in order to ensure the fair and correct treatment of wood.
The new project leader was asked to review the project and either get the project back on its original track or suggest a redirection. The project goal, to assist end users in best application of wood, was determined to be sound. In addition, the project leader recommended that resources continue to be allocated to participation in outside research efforts and other related activities. However, it was recommended that the project objective to develop computer-based decision tools be reassessed. Instead, the project leader recommended a course of action focused on tasks both shorter in term and smaller in scope, which will enable Forintek to deliver results better tailored to the immediate needs of industry in a time of building envelope moisture failure "crisis."
The new project plan is split into two areas: 1) address building envelope moisture failures that are due to existing information not arriving in the right hands (i.e., a technology transfer problem); and 2) address building envelope moisture failures that are due to a lack of information (i.e., a research problem). The technology transfer area will create a formal plan for communication to the building industry, will enable Forintek to experiment with developing pathways to that new target audience, and will provide the means for the wood industry to provide helpful durability information to the public through a relatively neutral third party (Forintek). The research area will explore opportunities for limited scope experiments or collaborative field studies of wood system durability performance, with the intent of verifying or modifying codes, standards and best practice guides.
This work was designed as a preliminary investigation into borate loss during the drying, and planing of wood. The objectives were to investigate borate losses from wood dried under different regimes and to investigate the effect of planing dried borate-treated wood on the retention or distribution of the preservative.
Green nominal 1 x 2 inch amabilis fir was cut into 1015 mm long samples. The samples were pressure treated with disodium octaborate tetrahydrate and allowed to diffuse for two weeks. The samples were then cut into four end-matched sub-samples with three of the sub-samples being subjected to either dehumidification-, kiln-, or air-drying. The dehumidification and kiln-drying were done in a sealed chamber with a condenser attached. Condensed water was collected to check for loss of air-borne boron during the drying. The fourth sample was used for analytical and penetration data.
Boron in borate-treated lumber was found to be air-borne at temperatures as low as 30°C with higher temperatures increasing the amount of borate found. However, the residual borate content after drying was not significantly reduced at 30°C or 50°C.
The relatively rapid oven-drying of small borate-treated samples at 50°C prior to analysis resulted in no significant loss of borate. However drying samples at 105°C reduced the borate retentions significantly. This indicates that it would be preferable to dry at 50°C to reduce losses of boron prior to analysis, thus giving more accurate results. In practice kiln-drying often occurs at temperatures between 50°C and 105°C. Further information is needed on borate losses between these temperatures.
Because surface layers after drying, contain higher levels of borate, planing borate-treated lumber will remove a disproportionate amount of boron from the treated lumber. This suggests that higher initial retention levels will be required to meet standards if the wood is to be processed after treating.
Borate-treated lumber stored under the temperature and relative humidity conditions that can prevail in, for example, the crawl space of a Japanese house, did not lose significant amounts of boron.
The relationship between the forest, the soil and the harvesting equipment must be understood if forest companies are to achieve sustainable and environmentally acceptable forest practices. As the soil is both the pavement over which harvesting and site preparation equipment must travel and the growing medium for future harvests, the forest industry must understand the impact of equipment activity on future fibre supply. To provide information on the interaction between forest equipment and the soils, FERIC organized a workshop for forest operations and agency staff, and contractors. More than 80 people attended the workshop that was held in Whitecourt, Alberta on February 26th, 1999. The focus of the presentations was to provide the audience with information and basic soil properties, soil mechanics and vehicle dynamics, and the effects of compaction on soil physical properties. In addition, other presentations included summaries of studies undertaken in western Canada on the impacts of felling and skidding equipment on forest soils, and impacts of harvesting activities and deciduous and coniferous regeneration. Finally, management strategies for minimizing soil degradation were discussed. These Proceedings summarize the presentations during the workshop.
Product separation during harvesting is often necessary to meet the needs of the many users of wood fiber. This report presents the results of a study whose goal was to determine the least expensive method for sorting six products using a harvesting system based on a feller-buncher, a single-grip processor, and a shortwood forwarder. In addition, the study was designed to determine the impact of product separation by the forwarder based on quality criterion. The results indicated that there was no advantage to species separation with feller-buncher; on the contrary, it was preferable to carry out all sorting with the processor. Furthermore, it was observed that the forwarder could perform a coarse separation based on quality class (decay content) at no additional cost.
A field test of six millwork preservatives has been ongoing for twenty years, using a simulated window corner, or "Y-joint", as the test unit. Three preservatives provided excellent protection to white pine and white spruce: 5% pentachlorophenol in varsol, phenyl mercury oleate in varsol, and 0.75% oxine copper in varsol.