Your search resulted in 12 documents.
Effect of felling time related to lunar calendar on the durability of wood and bamboo
-Fungal degradation during above ground exposure test for 2 years- (Preliminary report)
2005 - IRG/WP 05-20311
Current study was carried out to know whether the felling time of trees and bamboos based on lunar calendar affects natural durability of felled wood-bamboo or not. Each of one sugi (Cryptomeria japonica) tree of 28 years old and one Moso bamboo (Phyllostachys heterocycla) of around 3 years old was cut 12 times between February and December in 2003. Six sets of sugi tree and bamboo were felled in a day during “Hassen” period and the other 6 sets of them were also felled in a nearby non-“Hassen” day. There is a belief that “Hassen” should be avoided to perform destructive works such as cutting trees. “Hassen” lasting 12 days based on lunar calendar appears 6 times every year. After felling sample trees and bamboos, these specimens were subject to outdoor exposure at above ground level for 2 years. Properties of specimens such as moisture contents, mould and fungal resistance were examined periodically for 2 years. There was no clear difference in the degree of mould growth on the surface between specimens felled in a “Hassen” day and those felled in a non-“Hassen” day in the same month. The felling seasons, however, influenced the growth of mould on the surface of wood and bamboo clearly, which has been traditionally known in many cases. Fungal degradation evaluated by visual observation and the depth of pin penetration using Pilodyn during 2 years exposure was not affected by not only “Hassen” or non-“Hassen” also seasons when tree and bamboo felled.
K Yamamoto, S Uesugi, K Kawakami
Influence of felling time on the natural durability of norway spruce (Picea abies (L.) Karst.)
1998 - IRG/WP 98-10250
Natural durability was tested in a laboratory test according to EN 113. The test fungi were Coniophora puteana and Poria placenta. Additionally, the test method was modified by using water agar instead of malt agar, so that wood was the only nutrient source for the fungi. In a third attempt the samples were inoculated with Trichoderma harzianum before testing. The trees were felled on the 22.7.97 and the 22.12.97 at the same site (Mariensee, Lower Austria). The distribution of moisture in all trees was typical and showed no significant difference between summer and winter. The durability of the samples taken in summer did not vary according to their position in the stem (sapwood, transition wood, heartwood). By now (27.3.98) the durability test of the samples taken in winter is in progress - data will be available by the end of May and will be presented in Maastricht.
M Hirmke, K Messner, J Fellner, A Teischinger, R Wimmer
Proposal for co-operative work. Testing the ability of accidentally introduced tropical insects to survive the cold season in Europe
1976 - IRG/WP 155
By hibernation-experiments in the past it was found that not only the low temperatures may become fatal by freezing. In some experiments we found indications that larvae died by starvation. For example Lyctus africanus-larvae did so in some years with a cold winter (mean above 0°C). If you like to take starvation as a reason for death into account it may be useful to withdraw pieces of infested wood after different times of hibernation or to add new material later.
A study of wood quality of Juglans nigra and hybrid walnut (MJ 209xRA) : durability against Coriolus versicolor, density and MOR
2004 - IRG/WP 04-10522
The study investigated possible effects of harvesting season on some wood properties of Juglan nigra (JN) and a hybrid walnut (MJ209xRA). The samples were taken from trees which were harvested in June July, August, November of the same year, and March in the year after to determine whether there were any significant differences in wood properties as regards the harvesting seasons. In order to test the durability of the 648 wood samples white rot fungus Coriolus versicolor challenge test (EN113 (AFNOR 1994) was applied by using agar culture medium. The bending strength was also determined after a sixteen-week exposure to the above mentioned fungus. The data obtained clearly indicated that the heartwood of JN was more durable than its sapwood. JN sapwood was more durable than MJ209xRA sapwood. The same trend was observed with the Modulus of rupture (MOR : EN 310): the heartwood displayed higher MOR value than the sapwood. Wood density measurements also demonstrated that the wood density values of the sample heartwoods were much higher than those of the sapwoods. Results also illustrated that, from the wood durability point of view, March is the least interesting period for harvesting. June and November, on the other hand, proved to be more favourable periods as regards harvesting. This study clearly indicates that the durability and the strength of the hybrid walnut (MJ209xRA) are lower than those of the walnut (Juglans nigra), and this fact should be considered in the exploitation of hybrid wood.
B Charrier, F Charrier, D P Kamdem, J B Aurel, G Janin
The effect of felling time of year on CCA fixation rate and quality of selected hardwoods
1998 - IRG/WP 98-40116
White birch (Betula papyrifera), poplar (Populus sp.) and red maple (Acer rubrum) trees were harvested in winter, in spring, before the leaves flushed, after leaf flush and later in the summer. Sapwood discs were cut from the freshly felled trees, dried and cut into 25 mm and 19 mm cubes. The cubes were pressure impregnated with CCA-C and fixed under high relative humidity and at 50°C or at room temperature (21°C) conditions. Fixation rate was measured by expressing cubes periodically and analysing the expressate for CrVI content using a diphenyl carbazide indicator. The expressate was also examined for chromium, copper and arsenic using ASOMA X-ray fluorescence spectroscopy. Red maple wood harvested in spring fixed more slowly than wood cut in either the winter or the summer. This is thought to be related to the sugar, starch and other nutrient content of the wood at different times of the year. The time of year of felling had no consistent effect on the speed of fixation in white birch and poplar sapwood. Fixation quality was evaluated by leaching studies on 19 mm cubes using AWPA standard E 11-87. As has been observed elsewhere with red maple and other species, rapid fixation rate is accompanied by poor quality of fixation of CCA components, and especially of arsenic. We conclude that the season during which red maple is harvested can have a great effect of CCA performance in this species, which helps explain variable fixation rates and quality of fixation observed previously with this species.
Y T Ung, A Taylor, P A Cooper, D P Kamdem
A trial of "sour" felling to prevent bluestain by depletion of sapwood nutrients
2001 - IRG/WP 01-10404
Discoloration of conifer wood caused by bluestain causes large economic losses in Canada. Most deep stain develops in the log stage during storage or transport. In a search for control strategies that will not disrupt woodlands productivity we tested "sour" felling, termed "hagarashi" in Japan. The practice involves delaying the delimbing of freshly harvested trees. The tree continues to transpire and to respire. This could result in partial drying of the wood and/or faster depletion of sapwood nutrients needed for the growth of bluestain fungi. Field experiments were done compared sour-felled trees with ones immediately processed by a harvester/delimber. We examined the development of stain and also analyzed sapwood nutrients. The latter included lipophilic extractives, phenolics, soluble sugars, starch and total nitrogen. There was no stain in both sets of trees, attributable to unfavourably cool weather. The viability of ray parenchyma cells and the moisture content remained similar in both sets of trees. Despite being unable to show a benefit in reduced stain this work provided baseline data for the levels of the extractives in fresh and stored lodgepole pine trees. Starch was depleted to 20-30% of its original amount over the six week period, presumably as it was used by the dying tree.
A Byrne, A Uzunovic, D Minchin, C Breuil
Preservation of coppice wood for the fabrication of glued beams or panels
1987 - IRG/WP 3427
In this survey we will examine the specific problems concerning the conservation and the preservation of timber (issued from trunks of small diameter corresponding to products of clearings or coppices) destined for the fabrication of solid reconstituted elements. Thus for six metropolitan species of wood, we first characterized the biological deteriorations which occur after felling and their kinetics with respect to the exploitation period. We then defined two methods of treatment adapted to coppice timber, i.e. methods which are efficient and compatible with gluing and finishings. The efficiency of the treatments (applied to damp timbers) was verified by determining the penetration of the preservatives in the wood, by chemical analysis and biological assessment. These treatments (with CCA and CCB salts applied by vacuum and pressure) confer a permanent and high degree of protection to the timber from the first cut of the saw, dispense with the need for a temporary treatment of newly sawn timber and can be easily integrated into an industrial manufacturing process. The degree of protection conferred to the species does not appear to be affected by the humidity of the wood at the time of treatment.
G R Y Déon, R Schwartz
An analysis of the effects of some factors on the natural durability of pine (Pinus sylvestris L.) and spruce (Picea abies Karst.)
1986 - IRG/WP 1279
The effects of some factors on the natural resistance of pine and spruce sapwood against fungal decay and against attack of house-longhorn beetle larvae have been studied in laboratory tests and the results are evaluated by analysis of variance and regression analysis. Following conclusions were reached: Wood from summer-felled trees did not have a lower inherent natural durability against fungal decay and house-longhorn beetle than wood from winter-felled trees. Storage of pine logs in water had no significant effect on the weight losses obtained in laboratory tests with Gloeophyllum sepiarium and Fomitopsis pinicola but reduced the weight losses obtained with Phlebiopsis gigantea very significantly. In the case of outdoor use of wood, this result implies that the decreased nutritive value of wood from water-stored logs for certain fungi to some extent compensates for the effect of increased permeability. Wet storage also reduced the growth of house-longhorn beetle larvae. The effects of density on weight loss by fungal decay were different for the three test fungi. The growth rate of the house-longhorn beetle larvae in the inner sapwood was much lower than that in the outer sapwood. In comparison with between-trees variation and with differences between outer and inner sapwood the other observed effects, each on its own account, are of minor practical importance for larval growth.
J B Boutelje, T Nilsson, S Rasmussen
Leaching of the copper component from full scale decking boards during one summer season
2009 - IRG/WP 09-50260
The leaching of copper has been tested in laboratory and in outside exposure for freshly treated pine sapwood samples with three different copper preservatives, Cu HDO, copper quat and copper triazoles. We found in the laboratory leaching test that a fixation with warming to 60 °C (140 °F) for 48 hours without drying and then drying in the laboratory in room temperature gave the lowest leaching of copper. We also found that surface treatments with wood oils reduced the leaching, and that washing of the surface before testing had no effect. Full scale decking board samples (0.25 m2) were then exposed outdoors for rain. The rain water was collected and analysed for copper. After one summer season (about 600 mm rain) we found that the leaching differ for the three preservatives. All samples with a water borne surface treatment had the lowest leaching, about half the amount of untreated.
F G Evans
Chapter 5 - Nursing of bamboo
2007 - IRG/WP 07-10635-05
In this chapter various procedures and steps of nursing of bamboo have been described with introduction, methodologies, examples and photographs. The propagation, improvement and sustainable growth of bamboo are possible through proper nursing of bamboo. The nursing of bamboo includes proper felling or extraction, fertilization and earth filling, protection from diseases and injuries, silvicultural practices, stands and nursing practices etc., and deals with Ecology, Soil Science, Growth and Biomass, Management of bamboo. The total and individual topics have been found out through study, observation and review of literatures.
A K Lahiry
Color change of timber exposed outdoors - Influence of season exposure test starts
2019 - IRG/WP 19-40865
For the client the material and color of the exterior wall are important, because they affect the impression of the building . However, discoloration of the exterior wall begins as soon as the building is completed, by various factors such as rainfall. We tried to quantitatively evaluate the changes of the exterior wood, and to organize the influences of climate conditions, in order to use the discoloration as design factor. It seems that the difference in the color changes in an exterior wood surface is remarkably influenced by what season the test begins. In order to confirm the difference in the color changes, the starting test month was shifted by one month for each specimen. Those plates were scanned at some intervals to get image data and the chromaticity was measured with a colorimeter. As a result, the following was clarified. The color change was divided into the following two patterns. A: Red → yellow → white → black, B: Red → yellow → black. Black discoloration occurred due to the plate material reaching severe climatic conditions after the ΔL * value reached the maximum value. Lignin is eluted from wood with rain and decolored with ultraviolet rays to turn white . However, it seems that the plate material becomes black as soon as it reaches high-temperature and humidity (without passing through the white period). We believe that the white period is the period until it is hit by hard climate conditions. When mild conditions continue, the white period is extended. Initial discoloration is slow under mild conditions.
K Usami, H Ishiyama
The influence of climate changes on Central European forests with an emphasis on Slovenia
2022 - IRG/WP 22-50368
When forests are managed sustainably, they play an essential role in protecting climate and biodiversity. They protect soils and water resources, provide livelihoods, and contribute to the well-being of rural and urban communities. European forests are multifunctional and provide a range of ecosystem services. These include the production of renewable materials that can replace materials with a larger environmental footprint, thus also contributing to climate neutrality and overall sustainability. Forestry is one of the key sectors capable of reducing dependence on non-renewable resources, mitigating climate change, and thus enabling the transition to a circular bioeconomy. At the same time, forest ecosystems worldwide face a number of threats that are exacerbated by climate change. Global warming will affect future species distribution, timber supply and wood properties (quality). Conservation and management of forest genetic resources, the base of forest biodiversity and productivity, is an essential component of sustainable forestry. In addition, sustainable forestry requires a constant and efficient supply of high-quality seed and seedlings of forest trees. With a high share of forest cover and abundant natural resources, Slovenia shows great potential for transition into a circular bioeconomy. Due to the impact of climate change, recognition of the importance of biodiversity and the concepts of sustainable forest management, changes in the species composition of Slovenian forests are expected in the near future, which will be reflected in a higher proportion of deciduous tree species, affecting all actors in the forest-wood value chain. This paper aims to highlight up-to-date facts about the state of forests in Europe, forests and forestry in Slovenia, the importance of sustainable forest management for forest-based climate change mitigation and adaptation, the role of forest genetic resources and provision of tree seeds and seedlings for sustainable forest development.
J Gričar, L Krajnc, M Westergren, S Rus, H Kraigher