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Comparing microbial colonisation and Decay Rates of Wood from Sound and Aphid-Killed Kenyan-Grown Mexican Cypress (Cupressus lusitanica)
2006 - IRG/WP 06-10599
Samples of wood from 10, 15, and 30-year old trees attacked and killed by the cypress aphid (Cinara cupressi) and sound Kenyan-grown Cupressus lusitanica trees were investigated for variations in moisture content, density and susceptibility to microbial decay. MC varied with tree age, a normal trend, and between samples from aphid-killed and sound trees. In samples from 10, 15 and 20-year old sound trees, MC was higher by 11.1%, 8.6% and 7.8% respectively, than in samples from aphid-killed trees. Similarly density varied with age, to be expected, and between samples from aphid-killed and sound trees, being 3.5%, 2.6% and 2.1% higher in samples from sound trees of the 3 age classes. Exposure to riverwater and soil revealed a pattern of microbial colonisation and degradation normal for each environment. In riverwater, samples were mainly colonised by bacteria, actinomycetes, stain fungi, and softrot fungi, bacteria and softrot fungi being the main wood degraders, but their action on samples were slow and generally moderate in severity of attack. Exposure to soil followed a similar pattern of colonisation, the principal wood decaying organisms being bacteria and softrot fungi, and to a lesser extent brown and white rot fungi. Samples from both aphid-killed and sound trees were colonised and decayed in a similar fashion, but microbial decay in the soil environment was more pronounced than in riverwater. The soil block test recorded low weight losses after 2 weeks exposure, rising to between 29% and 36% after 12 weeks, with no significant differences between weight losses in samples from aphid-killed and sound trees, or tree age. The results of the study revealed that there are no significant differences between microbial decay susceptibility of wood from aphid-killed and sound trees, and that slight differences in MC and density did not influence decay rate. Consequently, wood from aphid-killed cypress trees should not be considered as of inferior quality, in terms of decay susceptibility, by wood processors and consumers.
R Venkatasamy


Comparative studies on penetration and retention of CCA (C) and creosote in wood from APHID-killed and sound Kenyan-grown Mexican cypress (Cupressus lusitanica)
2006 - IRG/WP 06-40352
Properties of wood from Kenyan-grown Mexican cypress (Cupressus lusitanica), attacked and killed by the cypress aphid (Cinara cupressi), in terms of density and treatability, were investigated in comparison to the properties of wood from sound trees. Density in small wood samples from aphid-killed trees was found lower than density in samples from sound trees, and reduced with tree age in samples from both. However, differences were slight, being 3.8%, 2.5% and 2.3% lower than density in samples of sound trees aged 10, 12 and 14 years respectively. Conversely, penetration and retention of both CCA and creosote were higher in samples from aphid-killed trees of the 3 age classes. Along the grain penetration of CCA was higher by 3.6%, 4.5% and 6.2%, and across the grain penetration higher by 3.8%, 7.0% and 11.3% in samples from aphid-killed trees of the 3 age classes respectively, compared to penetration achieved in samples from sound trees. Higher penetration of creosote in samples from aphid-killed trees was in the order 3.9%, 5.8%, 7.1% along the grain, and 3.7%, 6.2%, 11.9% across the grain. Along the grain retention of CCA in samples from aphid-killed trees was higher by 1.2%, 1.5%, 2.0%, and across the grain higher by 5.1%, 6.3% and 7.4% for the 3 age classes. Similarly, retention of creosote in samples from aphid-killed trees of the 3 age classes was higher by 3.2%, 4.5%, 5.6% along the grain, and 2.6%, 3.2%, 4.6% across the grain. Differences in density and treatability could not be properly explained, but was assumed associated with extensive sap depletion by aphids, interference with tree growth and normal wood formation, hence lowering of wood cell wall materials and increased cellular spaces within the wood cell wall structure of wood from aphid-killed trees. However, the results revealed that differences between wood from aphid-killed and sound C. lusitanica were minimal, and did not warrant wood from aphid-killed trees being branded as of lower quality, and restricted end uses.
R Venkatasamy, F M Opar


Acoustic communication between Microcerotermes crassus Snyder
1982 - IRG/WP 1158
An unusual acoustic communication within a nest of Microcerotermes crassus SNYDER is reported. The signals produced by the termites are described and possible reasons for this behavior are considered.
U Kny


Physical properties variation of sound and top dying affected sundriwood (Heritiera fomes) in mangrove forest of Bangladesh
2004 - IRG/WP 04-10504
Top dying of sundri (Heritiera fomes Buch.-Ham.) in the Sundarbans is considered to be the most severe of all the diseases of tree crops in Bangladesh. The wood samples from sound, moderately affected and severely affected sundri trees from three different tree heights for every individual test were collected and their respective physical properties were examined to make a comparison. It was found that density decreased with the increase of disease severity and was found 5% for both the cases. The volumetric shrinkages also increased due to top dying and were found 6.42% and 3.34% higher for moderately affected and severely affected trees respectively. Similarly the initial moisture contents also decreased due to top dying and were found 5.34% and 16.19% lower for moderately affected and severely affected trees respectively.
S C Ghosh, A K M A Bosunia, M A Islam, A K Lahiry


Estimation of the population of a sound colony of Coptotermes lacteus (Froggatt)
1988 - IRG/WP 1353
Selecting an area with a high termite hazard is deemed essential in locating field sites in order to screen potential termiticides and wood preservatives. Yet, quantifying termite populations in such sites remains imprecise. There are major problems associated with estimating populations of termites in mound colonies (either free-standing or in trees), and these are briefly discussed. In this paper we estimate the population of a mound colony of Coptotermes lacteus as 3.06 x 105. The estimate relates to foragers collected at baits that had been inserted into the mound. The technique adopted, "removal sampling", did not destroy the integrity of the mound nor incur unnecessary expense.
D M Ewart, J R J French


The effect of mortality diseases on wood quality of sissoo (Dalbergia sissoo Roxb)
2006 - IRG/WP 06-10569
Sissoo (Dalbergia sissoo Roxb.) is a lagre deciduos, fast growing, strong light demanding and leguminous tree specie. It is an important multipurpose specie widely being planted in the agro forestry and and social forestry pratices in Bangladesh, particularly in the north and south-western parts of the country. On account of its better quality, sissoo is valued as good as construction and utility timber in Bangladesh. It is used as high value timber, wood fuel, nitrogen fixing and fodder trees. For about a decade, sissoo plantings of varying ages have been found dying due to an unknown cause. By 1996 the mortality was wide spread especially in the western part of the country, and it affects the wood properties of sissoo. The wood properties are very important in selecting wood for numerous uses. So, a comparative study of various physical properties of wood among sound, moderately affected and severally affected sissoo trees was conducted. Sound, moderately affected and severally affected sissoo trees showed significant differences in respect of tangential, radial, longitudinal and volumentric shrinkage respectively. Radial shrinkage didn’t differ significantly among top, middle and bottom sections of a particular condition of wood and the same result was of tangential, longitudinal and volumetric shrinkage. The same trees also showed a significant difference in density, but the density didn’t differ significantly among the top, middle or bottom sections of a particular condition of wood. Besides these, the presence of decay, stain, tunnel and discolouration were observed which also determine the wood quality. In sound, sissoo wood these are absent, but in disease affected sisso wood decay, stain, tunnel and discolouration are present which deteriorate the wood quality. It is observed that the wood quality of sound sissoo trees have been found superior to that of moderately affected and severally affected wood.
M M Islam, M O Hannan, G N M Ilias


New approaches to practical evaluation method of bio-degradation of wooden construction - Non-destructive detection of defects using radar technique
2000 - IRG/WP 00-20214
There have been a number of researches and developments on the techniques and apparatus for the nondestructive evaluation of the biological deterioration in wood and wooden constructions, such as decay or insect attack in house, public buildings or in historically important architectures. As for the detection of the decay in wood, techniques using sound in audible or in ultrasonic frequency ranges, stress waves, heat wave and X- ray have been investigated, where the changes in the physical properties expressed in the wave form were related to decay. The change in the velocity, the attenuation or the frequency spectrum of these physical energy waves can be associated with the decrease of the specific gravity or the structural change due to decay. Some mechanical properties such as the boring resistance and the elastic properties of wood surface could be an indicator of decay. The dielectric property of wood and its relation to decay is also useful. Miller et al. (1989) applied a radar technique to diagnosing of standing trees. However the techniques previously developed are not always feasible. One of the possible reasons is that these physical or mechanical properties change not only on decay but also on other factors, such as the water content or the grain direction in wood. In addition, sometimes the techniques are less practical, strictly not non- destructive or too expensive. In practical maintenance operation of wooden constructions, visual inspection together with sampling method plays an important roll, however a specialized training is needed for the operator to get the skill of the diagnosing. In this study, to establish a practical evaluation method of bio- degradation in wooden construction, scanning using a newly developed portable radar apparatus was investigated. By comparing the results with other methods, a more practical method to evaluate the bio-degradation in wood was proposed.
Y Fujii, Y Komatsu, Y Yanase, S Okumura, Y Imamura, M Tarumi, H Takiuchi, A Inai


An investigation of the nutritional physiology of the wood-boring weevil Euophryum confine Broun
1994 - IRG/WP 94-10082
The digestion of Picea abies Karst and Pinus sylvestris L. by Euophryum confine, at two sites is reported in this study. The composition of sound wood, wood from the heads of the weevil tunnels and the frass egested has been determined by gravimetric analysis. A comparison of sound wood and wood ingested showed that weevils tunnelled in microbially decayed wood, while a comparison of the wood ingested and frass egested showed weevils digested 15.5% of the hot water solubles, 22.5% of the hemicelluose and 26.7% of the cellulose in wood during gut transit, assuming lignin remained unchanged.
A J Pitman, S M Cragg, G S Sawyer


Criteria for environmentally and socially sound and sustainable wood preservation industry
2006 - IRG/WP 06-50237
This paper is dealing with critical criteria for environmentally and socially sound and sustainable wood preservation industry. A research study supported by past experience, knowledge and training on relevant topics and consultation of relevant appraisal manual, training module and technical guideline revealed concise widespread checklists for sustainable establishment of wood preservation industry. Through this paper safe and sound site selection, safe land acquisition and involuntary resettlement, sound regulatory aspects, safe planning and information, safe design and construction, safe operation, appropriate environmental management plan (EMP) and environmental impact assessment (EIA) of wood preservation industry have been ensured. The relevant industrialists can easily follow the checklists during establishment or renovation of wood preservation industry.
A K Lahiry, M Hasan, M A J H Chowdhury


Preference of Reticulitermes flavipes (Kollar) for Southern Pine Blue-Stained Sapwood from Beetle-Killed Trees
2012 - IRG/WP 12-10763
Bark beetles and their associated Ophiostomatiod fungi are the major pests of pine forests in the southeastern USA, and termites are the major insect decomposers of dead trees and wood products in the southeastern USA. While both are the principal destructive insects of southern pine trees and southern pine lumber, respectively, no relationship between the two has apparently been reported in the literature. While recently inspecting bark beetle-killed southern pine trees, we noticed that subterranean termites were often present in the lower trunk of pines with incipient bark beetle infestations and always present in trees that had been dead for several months. This unusually rapid termite infestation suggested a possible attraction of termites to beetle-killed wood. AWPA E1 choice termite tests with three colonies of the subterranean termite Reticulitermes flavipes (Kollar) always showed a significant feeding preference for both air-dried and kiln-dried blue-stained southern pine sapwood compared to unstained southern pine sapwood. These initial results indicate that subterranean termites play a significant role in the ecosystem of southern pine forests and carbon recycling, and termite attack on southern pine lumber cut from beetle-killed trees may be associated with the death of the host tree. As the implications of these results may be of major importance to forest health, ecology, and utilization of wood products from the southern pines, we are conducting additional laboratory and field studies.
N S Little, J J Riggins, A J Londo, T P Schultz, D D Nicholas


Effects of heat treatment on sound absorption coefficients in nanosilver-impregnated and normal solid woods
2017 - IRG/WP 17-40770
Effects of impregnation with silver nano-suspension as well as heat-treatment on sound absorption coefficients (AC) were studied in tangential direction of five different solid woods based on their importance. AC was measured at two frequencies of 250 and 500 Hz. A 400 ppm nanosuspension was used for the impregnation; silver nanoparticles had a size range of 30-80 nm. Based on the obtained results, the species reacted significantly different in absorbing sound at the two frequencies. Impregnation with nano-suspension substantially decreased AC at the lower frequency of 250 Hz; it did not show any particular trend when AC was measured at the frequency of 500 Hz. Heat treatment significantly increased AC at the frequency of 250 Hz. ACs of mulberry tended to be similar at the two frequencies; in the other four species though, ACs were significantly different. High significant correlations were found in the hardwoods between the ACs measured at the two frequencies.
A Esmailpour, J Norton, H R Taghiyari, H Zolfaghari, S Asadi