Wood Quality Research Papers - Academia.edu (original) (raw)

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- Wood Quality, Basic Density

O presente estudo teve como objetivo determinar as propriedades físicas e mecânicas da madeira de Eucalyptus benthamii Maiden et Cambage. Foram determinadas as seguintes propriedades físicas: massa específica aparente a 12 e 0% de umidade, massa específica aparente básica e os coeficientes de contração, além das propriedades mecânicas, por meio dos ensaios de flexão estática, compressão paralela às fibras, cisalhamento e dureza, para a idade de seis anos. Com base nos resultados obtidos na determinação das propriedades físicas, a madeira de E. benthamii, na idade estudada, pode ser classificada como moderadamente pesada e dimensionalmente instável. Em relação às propriedades mecânicas, de modo geral, a espécie apresentou baixa resistência, o que possivelmente está relacionado com a grande proporção de madeira juvenil presente no material estudado. Palavras-chave: eucalipto, qualidade da madeira, propriedades tecnológicas.

- by Floresta Ambiente and +1
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- Wood Quality, Eucalyptus, Eucalipto, Technological properties

Mangrove forests consist of a mosaic of tree cohorts, each having a regeneration history that depends on episodic recruitment of seedlings based on the availability of a "regeneration niche". The aim of this study was to assess seedling population structure in Ceriops tagal natural monospecific stands and one eight-year old reforested stand at Gazi Bay, Kenya, to determine performance in terms of growth and survival over a period of two years. Four natural monospecific stands (two on the western creek designated as site 1 and 2, and two on the eastern creek designated as site 4 and 5) were identified with the reforested stand (on the eastern creek) as site 3. The vegetation structure of these stands and natural regeneration were assessed by Linear Regeneration Sampling. Regeneration Class I (RCI) seedlings of known age were tagged and their growth parameters (diameter, height, leaf production and number of nodes) and survival rates monitored for a period of two years. The reforested stand had the same basal area (2.2 ± 0.1 m 2 ha -1 ) as site 1 (2.1 ± 0.1 m 2 ha -1 ), and the former's mean height was also similar to that of western creek sites (1 and 2), but lower than the eastern creek sites (4 and 5). The western creek sites had the highest seedling mortality (61 % for both) and lowest growth rates recorded over the two year period compared to a mortality of 45 % for the eastern sites. An analysis of seedling growth over the two years as a function of measured environmental factors showed a weak interaction, with height above datum (HAD) and canopy cover showing the highest correlation of only 30 %. The high mortality on the western creek sites may be attributed to harsh environmental conditions due to the limited expanse of the intertidal area of the western creek mangroves compounded with anthropogenic pressure due to its proximity to human settlements. Overall, C. tagal forests at Gazi Bay seem to be more vulnerable to environmental stress because they occur at the upper intertidal area, which limits their long-term structural development. Of the four species common at Gazi, C. tagal is the least structurally developed with very low basal areas and mean heights, which are both important determinants of wood quality. These upper-shore forests therefore require management approaches distinct from those of other species to ensure that their natural regeneration and overall structural development are not unsustainably compromised.

- by J. Kairo
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- Weak interaction, Requirements Management, Wood Quality, Natural Regeneration

This review critically examines the role of boron (B) in forests in view of recent findings on B nutrition and the continuing occurrence of B deficiency. Many perceptions about the role of B in plants and its uptake and mobility have been altered since the last review on B in forest trees in 1990. Now there is evidence for a fundamental role of B in the formation of the pectic structure in primary cell walls in plants, and further roles in membrane function are being explored. In plants, channel-mediated B uptake, active B uptake and B uptake by mycorrhizas have been shown, B transporters have been identified, and B retranslocation has been shown. We explore these findings and their consequences on forest trees and on ecosystems that they dominate. Particular emphasis is placed on B retranslocation and B in mycorrhizal symbiosis, given their importance in trees.

- by Bernard Dell
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- Management, Forestry, Symbiosis, Forest Ecology And Management

Sapwood samples of Pinus pinaster wood were treated with a 70% furfuryl alcohol mixture. Weight percent gain (WPG), equilibrium moisture content, dimensional stability, MOE, bending strength, hardness, density and durability were determined. WPG was on average 38%. Equilibrium moisture content decreased more than 40%. Dimensional stability increased reaching an ASE of 45%. MOE was little affected by the treatment but bending strength increased by about 6%. Hardness increased by about 50%, and density by 37%. Mass loss due to Postia placenta and Coniophora puteana decreased by 96% and 86%, respectively. Furfurylation of Pinus pinaster wood shows an interesting potential to improve the wood quality for solid timber products. Kiefernsplintholzproben (Pinus pinaster) wurden mit einer 70% Furfurylalkohol-Mischung behandelt und die prozentuale Massezunahme (WPG), die Gleichgewichtsfeuchte, die Dimensionsstabilität, der Elastizitätsmodul, die Biegefestigkeit, die Härte, die Dichte und die Dauerhaftigkeit wurden bestimmt. Die prozentuale Massezunahme lag im Durchschnitt bei 38%. Die Gleichgewichtsfeuchte nahm mehr als 40% ab. Die Dimensionsstabilität nahm zu und erreichte ein Quellresistenzvermögen (ASE) von 45%. Die Behandlung hatte nur wenig Einfluss auf den Elastizitätsmodul, während die Biegefestigkeit um 6% zunahm. Die Härte erhöhte sich um ca. 50% und die Dichte um 37%. Der Masseverlust durch Postia placenta und Coniophora puteana ging um 96% bzw. 86% zurück. Die Furfurylierung von Pinus pinaster Holz zeigt ein hohes Potential zur Verbesserung der Holzqualität von Massivholzprodukten.

- by Lina Nunes
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- Building, Wood Quality, Forestry Sciences, Mass Loss

Juvenile wood has been known as a concept since
the 1960s, but its full impact has not been felt until it
comprises a major proportion of the wood harvested. A
conservative estimate would put it currently at around
50 per cent by volume of wood in a standing tree. Its
characteristics vary according to a number of internal
and external factors but it consistently represents the
lowest density, highest microfibril angle, and highest
spiral grain within each individual stem. For most
high value wood products it is considered undesirable.
Unless there are changes in the overall approach to
management of wood quality in radiata pine, it will
have an increasing financial impact on plantation
forestry due to the proportion of the harvest that will
not meet users’ requirements.

- by Dave J Cown and +1
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- Wood Quality, Juvenile wood

The cell wall of wood tracheids is made up of various layers, distinguished from one other by the alignment of the innumerable, fine crystalline cellulose microfibrils within each layer that helically wind about the cell lumen. Microfibrils themselves are embedded in a die den Durchschnitts-Mikrovibrillenwinkel in einem gegebenen Holzstück reflektiert. Aufgrund dessen wurden akustische Methoden entwickelt, um die Geschwindigkeit der Schallausbreitung zu messen, die direkt mit der Festigkeit des Holzes korreliert und damit auch abhängig ist von der Ultrastruktur der Zellwand. In der Grundgleichung, E dynamic =qV 2 , wird der akustische Modulus von zwei Komponenten abgeleitet, der Dichte, q, und der Schallgeschwindigkeit, V. Letztere bezieht sich auf die intrinsische Holzqualität und die Ultrastruktur der Tracheiden-Wand. Es wird gezeigt, dass die akustische Methode in der Lage ist, Bäume und Rundholz gemäß ihrer Eignung für Bauholz und für eine Bandbreite von Fasereigenschaften, im Interesse der Papierhersteller, zu sortieren und einzuteilen. Auf diese Weise finden akustische Methoden Anwendung bei der Aufzucht von Bäumen, ihrer Abholzung und Verarbeitung.

- by Håkan Lindström
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- Genetics, Building, Wood Products, Wood Quality

Hevea rubber clones are intensively cultivated in tropical regions of the world as main sources for Natural Rubber (NR) production which is one of the important raw materials for many industries. However, the heterozygous nature, long breeding time of trees and the prolonged period required for evaluation of mature traits are strong limitations for conventional breeding and selection methods. The development of methods for in vitro culture and genetic engineering has increased the possibility of producing rubber genotypes with improved latex yield, tolerance to tapping panel dryness (TPD) syndrome, growth rate and wood quality or reduction in undesirable traits. The combination of conventional breeding and molecular techniques will help to develop rubber trees with positive effects on the environment. However, the risks associated with the biotechnological applications should be carefully evaluated and field trials are to be performed with transgenic rubber tree. Genomic technologies were taken up by various research groups working on Hevea to identify new targets for breeding and/or complementary genetic transformation. In addition, molecular markers can provide simultaneous and sequential selection of agronomically important genes in Hevea breeding programs and effectively replace time consuming bioassays in early generation screens. With the advent of molecular techniques, several genes involved in rubber biosynthetic pathway have been characterized. Both HMGR and HMGS are essential enzymes involved in early steps of rubber biosynthesis. Among the genes identified, REF is a key rubber biosynthetic gene involved in polymerization of isoprene chain. However, further research is needed to use these identified genes for genetic manipulation of rubber tree. Most recently, a set of genes associated with TPD has been identified by SSH analysis. This review provides a comprehensive picture on rubber biotechnological research achievements in the last two decades.

- by rekha karumamkandathil and +1
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- Genetics, Plant Science, Genetic Engineering, Tissue culture

We review the main silvicultural interventions used when managing Eucalyptus plantations for solidwood products, including fertilising, pruning and thinning. The growth of a plantation and the quality of the wood produced is closely linked to the development of the tree crowns. These silvicultural interventions influence crown dynamics and can interact with each other, as well as the species, site and the age at which they are applied. This review focuses on the growth and physiological responses observed in Eucalyptus plantations, particularly from an Australian perspective. The implications for wood quality, while given some attention, are beyond the scope of this review. ß

The fungal pathogen Quambalaria pitereka can cause significant damage to spotted gum (Corymbia sp.) plantations in Australia. A series of seven progeny trials, involving seed from a range-wide collection from 527 individuals within 25 native populations of Corymbia citriodora sub-species variegata, were assessed for height growth and damage from Quambalaria around 1 year after planting. Infection at this young age has been found to detrimentally impact growth, form, and wood quality for many years. Genetic variance was found to be significant at both the provenance and family level. However, selection of families within provenances should lead to greater levels of genetic gain than what can be realized from selecting among provenances as estimates of additive genetic variance were consistently greater than estimates of variance among populations. Strong relationships between height and Quambalaria shoot blight (QSB) damage assessments in these trials were evidenced by very high genetic correlations between the traits; therefore, selection for any of these traits could be used to identify more productive and QSB-tolerant populations. While both provenances and families were found to interact with the trial environments at a similar level across traits, genetic correlations indicated that rankings for growth were be less stable than rankings for QSB tolerance across environments. Genetic parameter estimates derived from general and generalized linear models were very similar and either analytical method could be used to evaluate fungal damage.

- by Craig Hardner
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- Genetics, Agricultural Biotechnology, Damage Assessment, Wood Quality

The productivity of plantation forests is essential to meet the future world demand for wood and wood products in a sustainable fashion and in a manner that preserves natural stands and biodiversity. Plantation forestry has enormously benefited from development and implementation of improved silvicultural and forest management practices during the past century. A second wave of improvements has been brought about by the introduction of new germplasm developed through genetics and breeding efforts for both hardwood and conifer tree species. Coupled with the genetic gains achieved through tree breeding, the emergence of new biotechnological approaches that span the fields of plant developmental biology, genetic transformation, and discovery of genes associated with complex multigenic traits have added a new dimension to forest tree improvement programs. Significant progress has been made during the past five years in the area of plant regeneration via organogenesis and somatic embryogenesis (SE) for economically important tree species. These advances have not only helped the development of efficient gene transfer techniques, but also have opened up avenues for deployment of new high-performance clonally replicated planting stocks in forest plantations. One of the greatest challenges today is the ability to extend this technology to the most elite germplasm, such that it becomes an economically feasible means for large-scale production and delivery of improved planting stock. Another challenge will be the ability of the forestry research community to capitalize rapidly on current and future genomics-based elucidation of the underlying mechanisms for important but complex phenotypes. Advancements in gene cloning and genomics technology in forest trees have enabled the discovery and introduction of value-added traits for wood quality and resistance to biotic and abiotic stresses into improved genotypes. With these technical advancements, it will be necessary for reliable regulatory infrastructures and processes to be in place worldwide for testing and release of trees improved through biotechnology. Commercialization of planting stocks, as new varieties generated through clonal propagation and advanced breeding programs or as transgenic trees with high-value traits, is expected in the near future, and these trees will enhance the quality and productivity of our plantation forests.

- by Kamal Chowdhury and +1
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- Genetics, Developmental Biology, Plant Biology, Abiotic Stress

and sharing with colleagues.

- by Ahmed Koubaa
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- Wood Quality, Wood-Polymer Composites

Tarring experiments with pine tar from Scots pine (Pinus sylvestris) obtained from a traditionally accomplished kiln production have been carried out, in order to investigate potentials of improvement concerning tarring of the preserved Norwegian medieval stave churches. Pine tar coated test panels of pine wood were exposed to three different natural climates in Norway and on a regular basis characterised by visual assessment and gas chromatography-mass spectrometry (GC-MS) during 30 months of exposure. Moreover, test panels that were tar coated in the same way, however, on variable substrata, were exposed in a weatherometer. Tar obtained from different stages in the kiln production varies significantly according to chemical composition as well as coating ability. The weather resistance of tar from an early stage in the production proved superior compared to tar from a final stage. Boiling or seething of the pine tar at temperatures below 200°C prior to application increased weather resistance and durability of the coating, without accelerating the decarboxylation process in the tar sample. Even after exposure and weathering of the coated surfaces the initial characteristics of the liquid tar, in accordance with manufacturing temperature were detectable by GC-MS. Weatherometer experiments confirmed the results of the outdoor experiments and moreover showed that the quality of the substrata interacted with the tar coat and significantly affected the weather resistance. Despite different wood qualities of the weatherometer panels, the comparison of tar treatments, which were visually assessed on a macro level, was sufficiently evident to constitute a basis for renewed guidelines for tarring of stave churches.

- by Inger Marie Egenberg
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- Archaeology, Cultural Heritage, Medieval Architecture, Wood Quality

This paper deals with wood quality of Sclerolobium paniculatum for energy purposes. Samples were obtained from trees of two growing conditions: natural regeneration and experimental planting (five trees of each one). No significant difference was found between grouss. Wood was considered to be similar to those commonly used for energy purposes in Southern Brazil.

- by Jose Carlos
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- Wood Quality, Natural Regeneration, Southern Brazil

Heat treatment of Pinus pinaster and Eucalyptus globulus woods, two important species in Portugal, was performed in the absence of air by steaming, inside an autoclave, for 2-12 h at 190-210°C. Mass losses increased with treatment time and temperature reaching 7.3% for pine and 14.5% for eucalypt wood. The wood behaviour with moisture was improved. The equilibrium moisture content decreased by 46% for pine and 61% for eucalypt, the dimensional stability increased (maximum anti-shrinking efficiency in the radial direction of 57 and 90% for pine and eucalypt, respectively) and the surface wettability was lowered. In relation to mechanical properties, the modulus of elasticity was little affected (maximum decrease of 5% for pine and 15% for eucalypt) but the bending strength was reduced (by 40% at 8% mass loss for pine and 50% at 9% mass loss for eucalypt wood). The variation of properties was related to treatment intensity and mass loss but significant improvements could already be obtained for a 3-4% mass loss without impairing the mechanical resistance. The response of eucalypt was higher than that of pinewood. Heat treatment of eucalypt wood shows an interesting potential to improve the wood quality for solid timber products.

- by Bruno Esteves and +1
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- Materials Engineering, Plant Biology, Wood Science, Heat Treatment

An increasing demand, the higher prices and scarcity of wood in the market may cause the craft industry to search other raw materials than wood. Bamboos must be the raw materials that can be used as building construction and handicrafts industry with abundant potency. Black petung bamboo (Dendrocalamus asper (Schult) Backer ex Heyne c.v. ‘black’ is one of bamboos, which is widely used to support the craft industry. This study aims to determine the quality of black petung bamboo propagated by culm and rhizome cuttings, based on chemical properties as fiber content, ash content and starch content and physical properties as moisture content, specific gravity and shrinkage ratio T/R. The qualities for chemical and physical properties of black petung bamboo indicated to be 60.85 ~ 67.13% in culm cutting propagation and 61.34 ~ 62.73% in rhizome cutting propagation by fiber content, 2.90 ~ 4.52 % in culm cutting propagation and 4.19 ~ 5.38 % in rhizome cutting propagation by ash content, 6.32 ~ 8.17% in culm cutting propagation and 7.62 ~ 8.11% in rhizome cutting propagation by starch content, 9.27 ~ 10.17% in culm cutting propagation and 9.84 ~ 10.38% in rhizome cutting propagation by moisture content, 0.508 ~ 0.607 in culm cutting propagation and 0.491 ~ 0.567 in rhizome cutting propagation by specific gravity, 0.289 ~ 0.903% in culm cutting propagation and 0.253 ~ 1.047% in rhizome cutting propagation by shrinkage ratio (T/R). Black petung bamboo propagated by culm cutting has a better quality than that by rhizome cutting, according to the test results for chemical and physical properties.

- by Wawan Sujarwo
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- Bamboo, Wood chemistry, Plant propagation, Wood Quality

Aims: This work investigated the effect of thermal modification on some of the physical properties and mechanical properties of Daniella oliveri wood. Study Design: The study design used for this experiment was 3 x4 Factorial experiment in Completely Randomized Design. Place and Duration of Study: The study was conducted at the Federal University of Technology, Akure wood laboratory and the study lasted for 6 months. Methodology: Wood samples were thermally treated at the temperature of 120, 140, 160 and 180°C, for different durations of 1, 1.5 and 2 hours in a muffle furnace. The planks were air-dried to reduce the moisture content and then machined into the required dimensions in the direction parallel to grain with a circular saw. Thirty-nine defect-free samples of dimensions 20 mm × 20 mm × 60 mm were prepared for dimensional stability and compression test, static bending tests and the hardness tests to make a total of 117 samples. Original Research Article Iyiola et al.; CJAST, 35(2): 1-9, 2019; Article no.CJAST.48727 2 Results: The result showed that the average weight loss of the treated wood samples varied from 3.79% at 120°C for 1 hour to 7.51% at 180°C for 2 hours. The treatment led to reduction in density from 528 to 459 kg/m 3 at 180°C for 2 hours. The heat treatment also led to reduction in water absorption and volumetric swelling of the treated samples. The mean value for Modulus of elasticity (MOE) ranges from 2.17x10 3 N/mm 2 to 2.96 x 10 3 N/mm 2 for the treated samples while the untreated was 2.22x10 3 N/mm 2. Heat treatment brought about improvement in the maximum compressive strength and the Janka hardness parallel to the grain of wood samples. The value of compressive strength increased from 26.58 N/mm 2 to 41.71 N/mm 2 and hardness from 69.24 N to 75.5 N. It can therefore be concluded that thermal modification greatly enhanced the dimensional stability and mechanical properties of wood samples.

- by Ayanleye Oluwafemi and +1
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- Wood Science, Wood Quality, Wood Quality Improvement, Thermal Treatment

The selection criteria for the first generations in the Portuguese Pinus pinaster improvement program have been the growth rate and form traits. In this work we study the consequences of this selection on wood quality traits. This study assesses genetic and phenotypic correlation between growth, wood density components, lignin content and mechanical traits (radial modulus of elasticity and radial modulus of rupture) of 46 half sib families from a progeny trail located in Leiria, Portugal, originated from seed collected in a clonal seed orchard. A total of 552 seventeen-years-old trees (about half of full rotation age) were sampled at 2 m height. Height measured at 12 years old presented a higher genetic control (h 2 = 0.34) relatively to DBH, measured at 12 and 17 years old respectively (h 2 = 0.17 and h 2 = 0.15). The results of this study also showed that DBH growth is more dependent on latewood components than earlywood components and that higher growth in Mediterranean regions can be due to an increase of the period of latewood formation. Further, we can conclude genetic selection based on growth will not result in a decrease of wood density, will not affect the occurrence of spiral grain, and is possible to obtain an increase in the radial modulus of elasticity. The present study also showed that it is possible to select for increased growth with lower lignin proportion. Results also suggest that selection for growth at 12 years will probably not affect negatively the wood properties at 17 years. ß

As características físicas e mecânicas da madeira do eucalipto devem ser avaliadas para promover seu melhoramento e condição de aplicação mais adequada. Para que essa madeira se torne cada vez mais uma opção no mercado de pisos, além de sua caracterização, é importante avaliá-la em condições que simulem sua utilização em serviço. Assim, o objetivo deste trabalho foi avaliar o comportamento de madeira de sete clones de Eucalyptus urophylla para piso. Os ensaios de aplicação de esforço rolante, de atrito, de endentação causada por cargas aplicadas em pequenas áreas e de impacto por esfera de aço foram executados para simular o comportamento de pisos em serviço (ASTM D 2394). Os resultados mostraram que para os ensaios que simulam o uso de pisos em serviço, ocorreu diferença significativa entre os clones e a posição radial de amostragem, exceto para o ensaio de impacto por esfera de aço, que não apresentou diferenças entre os clones. Assim, entre os sete clones e posições de amostragem na tora, pôde-se identificar madeira potencialmente apta para aplicação em pisos. Destas, em ensaios que simulam a aplicação de pisos em serviço, as madeiras externas dos clones RB59, VM1 e RB121 apresentaram os melhores comportamentos frente aos ensaios de impacto por esfera de aço, esforço rolante, atrito estático, atrito dinâmico e endentação por cargas aplicadas em pequenas áreas.

- by Paulo F E R N A N D O Trugilho
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- Wood Quality, Coefficient of Friction

European ash (Fraxinus excelsior L.) is common throughout much of Europe and is a valuable broadleaved tree due to its ecological characteristics, outstanding wood properties and high economic value. It is a fast growing species, associated with several forest types and with a scattered distribution in many different forest communities. In this review, we sum up essential characteristics of European ash, relevant to the further development of silvicultural practices. The paper covers site requirements, regeneration and stand establishment, growth dynamics and wood quality, and health and robustness. The review also highlights implications for silviculture and summarizes new information on ash dieback, a phenomenon which is observed in many European countries. Ash grows best on fertile, pH-neutral, deep, freely drained soils and such sites should be favoured if the aim is for high quality timber. Ash grows well at wide spacing which can result in enlarged ring width and increased lat...

- by Jo Clark
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- Forestry, Wood Quality, Forestry Sciences, Wood properties
- by Cuauhtemoc Saenz-romero and +2
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- Genetics, Climate Change, Gene Flow, Forest Ecology And Management

The production of wood pellets has grown considerably in the last decades. Besides woody
biomass, other feedstocks can be used for pellet production. Among these, miscanthus presents
some advantages because, even if specifically cultivated, it requires low inputs such as fertilisers and
pesticides and shows high biomass yield (up to 28 tons of dry matter ha􀀀1 in Europe). Even if in
the last years some studies evaluated the environmental impact of woody pellet production, there
is no information about the environmental performances of miscanthus pellet production. In this
study, the environmental impact of miscanthus pellet was evaluated using the Life Cycle Assessment
approach with a cradle-to plant gate perspective. Primary data were collected in a small-medium size
pelletizing plant located in Northern Italy where miscanthus is cultivated to be directly processed.
The results highlight how the miscanthus pellet shows lower environmental impact compared to
woody pellet, mainly due to the lower energy consumption during pelletizing. The possibility to
pelletize the miscanthus biomass without any drying offsets the environmental impact related to the
miscanthus cultivation for all the evaluated impact categories (except for Marine eutrophication).
In detail, for global warming potential, 1 ton of miscanthus pellet shows an impact of 121.6 kg CO2
eq. (about 8% lower respect to woody pellet) while for the other evaluated impact categories the
impact reduction ranges from 4 to 59%. Harvesting, which unlike the other field operations is carried
out every year, is by far the main contributor to the impacts of the cultivation phase while electricity
is the main contributor to the pelletizing

- by Andrea Rosario Proto
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- Biomass energy, Green Energy, Miscanthus agronomy, Pellets
- by Shakti Chauhan
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- Wood Products, Wood Quality, Forestry Sciences, Wood properties

The practice of combining row and selective thinning in commercial pine plantation silviculture carries the risk of unwanted irregularities in tree distribution, a situation that is aggravated when tree selection during marking is poor. The potential consequences of poor tree selection are accentuated by gaps along row removal. This leads to spatially asymmetric growing space to adjacent trees. The effect of irregular stand structures on tree morphology and growth are investigated in this study, and are based on two stands of Pinus patula (Schiede ex Schltdl. et Cham.) in Langeni Plantation, South Africa. A comparison between trees grown in an all-sided and one-sided spatial competition situation is presented to assess the degree of differences between the two situations. Results of this study show significantly larger crown diameters, crown lengths, longer and thicker branches, disproportionately one-sided crown growth and a reduction in space-use efficiency in stands with irregular competitive status. These factors potentially negatively affect saw timber quality and volume production from the stands at final felling.

Togolese teak (Tectona grandis L.f) is highly resistant to pathogen attack, but variability in natural durability exists between trees of different ages, plantations and geographical zones. Therefore, further information concerning this parameter of wood quality is necessary; however, traditional testing methods are difficult and timeconsuming to carry out. We tested the possibility of using colorimetry to determine durability in heartwood samples taken from a wide range of trees.

- by H. Baillères
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- Plant Biology, Wood Quality, Teak, Trees

- by Teija Ruuhola
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- Management, Forestry, Symbiosis, Forest Ecology And Management

This study presents the results from seven international provenance trials of Pinus kesiya established in Colombia, South Africa, Swaziland, Vietnam and Zimbabwe. The traits evaluated were total volume per hectare, stem straightness, branch diameter, forking and foxtailing, at ages 5, 6, 7 or 8 years from planting. The tested material included 28 seedlots, comprising 24 provenances from the natural range of the species distribution and four local seed sources from Madagascar and Zambia. Survival was generally high, with percentages exceeding 85% in most of the trials. Significant provenance variance was found for total volume per hectare, stem straightness, branch diameter and foxtailing in all of the trials where these traits were measured. Forking exhibited significant provenance variance in only four of the seven trials measured. Across-site analysis for single traits used a factor analytic structure to model the provenance effects in each trial, and indicated that the practical importance of genotype by environment interaction was not great for the examined traits, as the majority of the provenances did not display relevant ranking changes across trial sites. Bivariate analysis across sites indicated that provenance correlations involving total volume per hectare, stem straightness and forking were statistically significant, moderate to high, and their signs suggested that simultaneous improvement could be achieved in these traits following provenance selection. However, these traits were significantly and adversely correlated with foxtailing. Provenance correlations between branch diameter and the other traits were generally low and not significantly different from zero. Vietnamese provenances, as well as local seed sources from Madagascar and Zambia, provided favourable combinations of growth and wood quality traits, and thus could have an important value for provenance research, seed supply and breeding. ß

- by Lars Graudal
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- Forest Ecology And Management, Vietnam, Biological Sciences, Growth

Genetic variation for wood quality traits and diameter growth for radiata pine (Pinus radiata D. Don) at age 20/21 years was estimated from eight trials in Australia. The traits studied were wood density, acoustic time-of-flight (an indirect measure of stiffness) and diameter at breast height (DBH). Wood density and DBH exhibited significant additive genetic variation whereas non-additive effects were not significantly different from zero. Time of flight was also not significantly different from zero for both additive and non-additive effects, respectively. Average single-site heritability estimates (±SE) for wood density and DBH were 0.38 ± 0.10 and 0.16 ± 0.08, respectively. Pooled-site heritability estimates for wood density and DBH were 0.38 ± 0.10 and 0.08 ± 0.10, respectively. For density, there was little evidence of genotype-by-environment interaction (GEI) across the eight trials at the additive level (type B additive genetic correlation; r BADD = 0.73 ± 0.08) and type B genetic correlation for full-sib families (r BFS = 0.64 ± 0.08). In contrast, the type B additive genetic correlation for DBH was lower, (r BADD = 0.51 ± 0.14), suggesting evidence of GEI. However, type B genetic correlation for full-sib families was moderate (0.63 ± 0.11) for DBH, suggesting that there may be some stable full-sib families. On the basis of the results of this study, GEI should be considered in order to optimise deployment of improved germplasm in Australia.

- by moe sib
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- Genetics, Agricultural Biotechnology, Time of Flight, Wood Quality

To determine the genetic parameters of growth traits and wood density (estimated by Pilodyn penetration) in a population of Eucalyptus grandis formed by families from 11 seed origins in NE Queensland, Australia and a local land race, 8.5-year-old progenies established in three sites in NE Argentina were evaluated. Local trees exhibited higher growth rate at two sites and better stem form, but also deeper Pilodyn penetration, at all sites; thus, there is potential to infuse new genetic variation into the current breeding population in the region. A significant amount of genetic variation was found for all traits assessed, with growth traits [diameter (DBH), height (HT) and volume (VOL)] showing different genetic structure and degree of genetic control as compared to stem straightness (FORM), bark thickness (BARK) and Pilodyn penetration (PILO). The effect of origin was negligible for growth traits while it was important for the other traits, so it should be considered in the selection strategy; in addition, individual heritability for growth traits (0.11-0.16 in the combined analyses) was generally lower than for the other traits (0.20-0.35). Genetic correlations between sites for all traits were high enough to indicate that genotype-environment interaction would not affect the selection program by using a single breeding population for this region. Genetic correlations between growth traits were high (r g > 0.80), and negligible between these and FORM; the only unfavorable genetic correlation was between PILO and BARK (r g = -0.44). Age-age correlations for growth traits and FORM were very high (r g > 0.90). Results suggest that all traits evaluated could be handled in a breeding program, either independently or combined, without negative correlated effects. Early selection for growth traits and stem form is also possible, with major savings in time.

- by J. Jesús Vargas Hernández
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- Genetics, Wood Quality, First Year, Wood Density

The genetic control and phenotypic and genotypic correlations among wood density, modulus of elasticity, height, diameter, and volume were assessed using 967 trees representing 20 unrelated 32-year-old coastal Douglas-fir full-sib families growing on four (spaced and pruned vs. control) comparable test sites. Generally, no significant differences were observed between treatments, indicating their limited effect at assessment time. Family effect did not differ for the growth traits; however, significant differences were observed for wood density and both in situ methods (drilling resistance and acoustic velocity). Growth and wood quality attributes, individually, produced high and positive phenotypic and genetic correlations; however, high and negative correlations were observed between individual variables belonging to the two suites of attributes. Individual tree heritabilities were low for growth (0.04 to 0.08) and modest to high for wood quality attributes (0.14 to 0.68). The observed heritabilities and phenotypic and genotypic correlations imply modest to strong genetic control; however, they operated in opposing direction. The significant and consistent genetic correlations between the in situ methods and wood density and stiffness support their use as a non-destructive and economic assessment approach. The reliability of the in situ assessments was verified through cumulative pith-tobark wood density assessment, resulting in inconsistent genetic and phenotypic correlations for early growth years. These latter findings imply that caution should be used in employing these in situ techniques as early screening tools in breeding programs.

- by Fikret Isik and +1
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- Genetics, Agricultural Biotechnology, Heritability, Wood Quality

The physiological capacities of seedlings to cope with drought may be subject to strong selective pressure in the context of future climate scenarios, threatening the regeneration and sustainability of forests. Characterization of the responses and the variability between species is of interest to breeding and domestication programs. In this study, our main goal was to describe some of the physiological mechanisms involved in the drought response of Nothofagus nervosa and N. obliqua, two forest species of ecological and commercial importance (high wood quality) in NW Patagonia. We tested for differences in water status, gas exchange and survival in response to a gradually imposed severe drought. Based on cavitation vulnerability curves and hydraulic conductivity measurements, we can conclude that N. obliqua stems have higher specific hydraulic conductivity and somewhat lower vulnerability to cavitation than N. nervosa stems, leading it to sustain higher stomatal conductance under non-severe drought conditions. N. obliqua had higher photosynthetic capacity than N. nervosa, due both to characteristics of its hydraulic architecture and to its higher metabolic capacity. Our results indicate that both species present characteristics of plants susceptible to water stress. Also, both species showed behavior resembling an anisohydric response. This behavior results from a lack of stomatal control over transpiration while the soil dehydrates, probably accompanied by very high vulnerability to cavitation. In contrast, both species had similar high stomatal sensitivity to vapor pressure deficit when soil water was limiting.

- by Tomás Schlichter
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- Plant Biology, Drought Stress, Patagonia, Water Stress

Miombo woodlands cover a large part of Southern Africa and contribute an important wood source for the local
wood industry. The already observed and further predicted changes in climatic patterns can be expected to affect
the wood properties of Miombo tree species. The diameter growth response to climatic variables related to water
availability and temperature of three Miombo woodland tree species (Brachystegia spiciformis, Burkea africana and
Isoberlinia angolensis) was analysed using 245 trees samples in three climatic zones in Zambia. Sites were chosen
to represent the range of site conditions under which these species grow in the Miombo woodlands of Zambia.
The study sites differed in moisture availability and average temperature, as indicated by De Martonne’s aridity
index. Tree-ring width correlated with site conditions and differed significantly between sites. A positive correlation
was found between mean annual precipitation and annual ring width, as well as growth variation, while growth
was almost non-responsive to temperature variations. For all three species, trees growing on the outer limits
of the species’ range were found to be more responsive and sensitive to variability in annual rainfall than those
growing under optimal conditions. All three species showed significant variation in inter-annual ring width with
environmental conditions. Water availability was found to have a much larger effect than temperature, especially on
drier sites.

- by Francis Munalula
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- Sawmilling, Wood Quality, Tree-Ring Research, Wood Based Panels

3 Arborgen Tecnologia Florestal, Campinas, SP, Brasil. RESUMO O estudo foi desenvolvido para avaliar o potencial de cinco novos clones de eucalipto para a produção de madeira serrada. Foram utilizadas toras de três clones do híbrido Eucalyptus grandis x Eucalyptus urophylla, um clone de Eucalyptus grandis e um clone de Eucalyptus urophylla. Em todos os materiais genéticos foram avaliados a porcentagem de cerne, o índice de rachaduras de topo das toras e das tábuas, o arqueamento e o encurvamento verde e seco nas tábuas. Houve influência significativa dos clones na qualidade das toras e na qualidade da madeira serrada. Para o arqueamento (verde e seco) e encurvamento (verde) todos os clones foram classificados com empenamento leve. Após o desdobro, os clones 3 (Eucalyptus grandis x Eucalyptus urophylla), clone 4 (Eucalyptus grandis) e clone 5 (Eucalyptus grandis x Eucalyptus urophylla) apresentaram rachadura leve. Sendo assim, os clones 3, 4 e 5 mostraram-se como potenciais fontes de matéria prima para produção de madeira serrada. Palavras-chave: Qualidade da tora; Qualidade da madeira; Processamento da madeira. Quality of the log and wood of Eucalyptus clones for use in lumber industry ABSTRACT The study was conducted to evaluate the potential of five new eucalyptus clones for lumber production. Logs of three clones of the hybrid of Eucalyptus grandis x Eucalyptus urophylla, one clone of Eucalyptus grandis and one clone of Eucalyptus urophylla were used. In all genetic materials were evaluated the core percentage and the top splits index for the logs and the spring, bow and splits for the green and dry boards. The clones had a significant influence on the logs and lumber quality. Considering spring (green and dry) and bow (green), all clones were classified with light warping. After sawing, the clone 3 (Eucalyptus grandis x Eucalyptus urophylla), clone 4 (Eucalyptus grandis) and clone 5 (Eucalyptus grandis x Eucalyptus urophylla) presented light splits. Therefore, the clones 3, 4 and 5 proved to be potential sources of raw material for lumber production. Introdução Entre as espécies plantadas que abastecem a indústria madeireira no Brasil, o eucalipto está entre as mais importantes, devido a taxa de crescimento, facilidade de implantação em grandes maciços, rusticidade e também pela gama de aplicações de sua madeira (LATORRACA et al., 2015). A grande parte destas espécies são resultado do melhoramento genético e clonagem de material, uma operação que tem se tornado uma das principais opções para o aumento simultâneo da produção e melhoria da qualidade da madeira, controlando a expressão das características de interesse (BOTREL et al., 2007).

- by Claudio juizo
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- Wood Processing, Wood Quality

Assessments of genetic variation in wood properties are difficult and expensive to carry out. as a consequence, the inclusion of wood quality traits in eucalypt breeding programmes has to date been limited. this study was part of a large investigation into the use of non-destructive methods of assessing wood properties by comparing the results with those from traditional destructive methods. this component of the study investigated the genetic variation in linear shrinkage of 152 open-pollinated families of Eucalyptus pilularis (Smith) at 17% m.c., 12% m.c., and 5% m.c. increment cores and test blocks were used to assess radial and tangential shrinkage as well as their ratio. heritability estimates were moderate for tangential shrinkage but not significant for radial shrinkage or the ratios of the two. the genetic correlation between shrinkage measured on cores and on blocks at this stage was not sufficient to justify the use of increment cores alone in genetic assessments. Basic density had a moderate and negative correlation with tangential shrinkage, suggesting that selecting for higher basic density may help reduce tangential shrinkage. the increment core method was not successful at measuring radial shrinkage due to core distortion. Measurements from scans and blocks showed that radial shrinkage was not heritable.

- by Jerome K Vanclay
- •
- Genetics, Wood Quality, Forestry Sciences, Wood properties

Anatomical studies were made on the structural and decorative elements of the wooden ceiling of the 12 th century Cappella Palatina in Palermo, Sicily, to identify the timbers used, analyse their likely provenance, and discuss the selection criteria used by the builders. One hundred and fifty fragments were examined. Abies sp., Pinus sp., Betula sp., Populus sp. and Fagus sylvatica were found and all are most probably from Sicily. Some of the Abies fragments probably belong to Abies nebrodensis as they have exceptionally long tracheids, very tall rays, and abundant crystals. This species was over-logged in the past and now only 29 trees remain in the Madonie Natural Reserve in Sicily. Abies and Pinus are found in vertical and horizontal painted panels, while Populus, Betula and Fagus were used in smaller parts of the muqarnas (painted niches). The choice of species seems to have been related to original tree size. The large size of the Abies boles meant that quarter sawn panels could be used. Sicilian Abies was highly valued at that time for its wood quality. Special attention was paid to the problem of distinguishing partly degraded Abies and Cedrus woods. However, the scalloped torus in some samples displayed ambiguous features and these samples were therefore classified as Abies/Cedrus.

- by Marcello Romagnoli
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- Wood Anatomy, Populus, Wood Quality, Selection Criteria

A espécie Acacia mangium apresenta potencial silvicultural no país, em função da sua boa adaptação e do seu rápido crescimento. É muito utilizada em recuperação de áreas antropizadas, porém ainda pouco estudada no que se refere às propriedades tecnológicas de sua madeira, sobretudo em árvores mais jovens. Dessa forma, o objetivo deste trabalho foi avaliar a densidade básica, o teor de extrativos, o valor do pH e a capacidade tampão da madeira de Acacia mangium, além de descrevê-la anatomicamente. Foram utilizadas árvores com 4,2 anos, provenientes de reflorestamento misto com o híbrido Eucalyptus urophylla × grandis, localizado no município de Santa Bárbara, região do Vale do Rio Doce, Estado de Minas Gerais. Análises químicas, físicas e anatômicas na madeira obtida em diferentes alturas do tronco foram realizadas. A densidade básica média encontrada foi de 0,34 g.cm –3. A madeira não apresentou uma grande acidez e os valores de pH e capacidade tampão da madeira variaram de 5,45 a 5,90 e de 0,05 a 0,104 mmolNaOH, respectivamente. Os extrativos encontrados apresentaram baixos teores, indicando não haver uma variação significativa ao longo da árvore. Os caracteres anatômicos apresentaram comportamento com pequenas variações quando comparados com árvores mais adultas. Palavras-chave: tecnologia da madeira, qualidade da madeira, madeira juvenil.

- by Floresta Ambiente
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- Wood Quality, Wood Technology, Tecnologia Da Madeira, Juvenile wood
- by Alfas Pliura
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- Forest Ecology And Management, Forest Ecology, Biological Sciences, Growth
- by Rodrigo Vale
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- Experimental Design, Wood Quality, Forestry Sciences, Wood Density

Pinus radiata D. Don trees were grown in the presence and absence of the woody weed broom (Cytisus scoparius L.) on a dryland site for 2 years to determine the effects of competition from weeds on wood properties in juvenile trees. Wood property measurements made on cross-sections from the bark to the pith were scaled to convert results from distance to a time basis using sigmoidal equations fitted to monthly measurements of tree diameter. When averaged across the 2 years, the presence of the weeds significantly increased wood density (+11%), wall thickness (+6%) and modulus of elasticity (MOESS, +93%), and significantly reduced microfibril angle (MFA, −21%) and radial diameter (−8%). Radial growth rate was significantly correlated to wood density, and this relationship held across both treatment and age. At the seasonal scale, there was close correspondence between changes in MFA and growth rate. Ring width was significantly related to both MFA and MOESS at the annual scale. Although both of these relationships held across treatments, year significantly influenced the value of coefficients in the relationships. The results highlight the direct effects of the presence of weeds on wood properties and the need to consider silvicultural treatments appropriate for balancing gains in productivity with losses in wood quality for timber production.

- by Brian Richardson
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- Plant Biology, Seasonality, Wood Quality, Trees

Selection for both growth and wood quality is the primary goal of many tree breeding programs. In order to investigate the impacts of such selection on adaptive traits, observations were made on phenology, drought resistance, xylem conductance and xylem vulnerability to cavitation of 2-year-old seedlings of lodgepole pine (Pinus contorta Dougl. Ex Loud var. latifolia Engelm) from four subpopulations: (1) fast height growth and high wood density (FH); (2) slow height growth and high density (SH); (3) fast height growth and low density (FL); and (4) slow height growth and low density (SL). Results showed that the impact of the selection on phenology was minor; differences in growth among subpopulations were mainly attributable to maximal growth rate and the duration of the period of rapid growth. The FL subpopulation showed a significantly stronger productivity decline in response to moderate drought compared to the two slower-growing subpopulations. The FH subpopulation showed significantly higher xylem specific conductivity than the two slower-growing subpopulations, and greater resistance to cavitation than the other three subpopulations, suggesting the possibility of selecting families that combine fast growth, high wood density and drought tolerance.

- by Tongli Wang
- •
- Plant Biology, Growth, Wood, Cavitation

Background Genetic selection for one trait can have an impact on other important traits for final use; thus, it is important to assess the correlation between traits. • Methods Genetic control and relationships among lignin content predicted by near infrared spectroscopy, radial modulus of elasticity (MOE Rad ) and the radial modulus of rupture (MOR Rad ), as well as its correlations with wood density components and spiral grain were assessed by estimating heritability, phenotypic and genetic correlations using 552 Pinus pinaster trees from 46 half-sib families.

- by Ana Alves
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- Near Infrared, Near Infrared Spectroscopy, Wood Quality, Coefficient of Variation

Pinus radiataD. Don trees were grown in the presence and absence of the woody weed broom(Cytisus scoparius L.) on a dryland site for 2 years to determine the effects of competition from weeds on wood properties in juvenile trees. Wood property measurements made on cross-sections from the bark to the pith were scaled to convert results from distance to a time basis using sigmoidal equations fitted to monthly measurements of tree diameter. When averaged across the 2 years, the presence of the weeds significantly increased wood density (+11%), wall thickness (+6%) and modulus of elasticity (MOE SS , +93%), and significantly reduced microfibril angle (MFA, −21%) and radial diameter (−8%). Radial growth rate was significantly correlated to wood density, and this relationship held across both treatment and age. At the seasonal scale, there was close correspondence between changes in MFA and growth rate. Ring width was significantly related to both MFA and MOE SS at the annual scale. Although both of these relationships held across treatments, year significantly influenced the value of coefficients in the relationships. The results highlight the direct effects of the presence of weeds on wood properties and the need to consider silvicultural treatments appropriate for balancing gains in productivity with losses in wood quality for timber production.

- by Michael Watt and +1
- •
- Plant Biology, Seasonality, Wood Quality, Trees

Genetic variation and genotype by environment interaction (G×E) were studied in several juvenile wood traits of 11 year-old loblolly pine trees (Pinus taeda L.). Wafer thin (200 µm) samples from juvenile (ring 3) and transition (ring 8) wood of 12 mm increment cores were analyzed. Transition wood had higher α-cellulose content (46.1%), longer fiber (1.98 mm), and higher coarseness (0.34), but lower lignin (29.7%) than juvenile wood (cellulose 40.9%, fiber length 1.4 mm, coarseness 0.28 and lignin 30.3%). General combining ability variance for the traits explained 2% to 10% of the total variance, whereas the specific combining ability variance was negligible, except for α-cellulose content in transition wood (2%). Specific combining ability by site interaction variance explained from 5% (fiber length) to 37% (lignin) of the total variance. Weak individual-tree heritabilities were found for all the traits, except coarseness, which was moderately high in both juvenile (0.39) and transition wood (0.30). Full-sib and half-sib family heritabilities of traits ranged 0.29 to 0.72. Genetic correlations of wood quality traits with volume and stem straightness were weak, while favorable genetic correlations of lignin with cellulose, coarseness and fiber length were observed. Implications on forest tree improvement programs were discussed.

- by Bailian Li and +1
- •
- Wood Quality, General Combining Ability, Specific Combining Ability, Forestry Sciences

To better understand the genetic control of growth and wood properties in the hybrid poplar (Populus spp.), genetic relationships of selected wood properties with growth traits were examined in a 3-yr-old clonal trial located in Windsor and St-Ours, southern Quebec, Canada. In total, 371 trees from 21 hybrid poplar clones were sampled at the two locations. Clone effects are stronger than growth traits effects on wood density and initial moisture content. The estimated clonal repeatability for wood density (0.92) and initial moisture content (0.80) across the two sites are thus considerably higher than for dbh (0.64) and tree height (0.72). Neither wood density nor mean fiber length were found to significantly correlate with growth traits. This suggests that in the hybrid poplar clones selection for growth traits will not result in a significant reduction in the wood quality traits. Selection for stem dry fiber weight appears to be an optimal selection strategy, as it will lead to the highest genetic gain in stem dry fiber yield, or maximum fiber production while wood density is improved. FOR. SCI. 49(6):00-00.

- by Ahmed Koubaa
- •
- Populus, Forest science, Wood Quality, Tree growth

Wood and fibre properties such as wood density, microfibril angle, and modulus of elasticity are industrially relevant factors in determining the mechanical properties of wood. Radial ring-level predictive models of these properties were developed using balsam fir data from a long-term trial in New Brunswick (Canada), where precommercial thinning was applied 8 years after the site was harvested. The mixed effects models developed accounted for most of the variability in wood density (68 %), microfibril angle (94 %), and modulus of elasticity (77 %) with low RMSE. This study shows that balsam fir wood and fibre properties are strongly related to distance from the pith, particularly in the first 20 mm, and much less to annual ring width. Disk height and selected weather variables related to air temperature during the growing season significantly improved the models, whereas the effect of precommercial thinning was not significant. These equations can be incorporated into computer models, such as Optitek, that simulate mill recovery and wood properties to obtain accurate information on wood products. The unexplained variation in these models is likely related in part to between-tree genetic variation, which is unknown in this study.

- by Francesco Cortini
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- Wood science and technology, Wood Quality, Wood Density, Modulus of Elasticity

The most efficient wood-rotting fungi are basidiomy cetes and ascomycetes. In general, microbial decay processes go along with a loss of wood quality. For example, brown rot decay leads to a rapid decrease in wood strength a lready in early stages of growth. On the other hand, a projected bi odegradation may enhance the quality when sound woo d or

O objetivo deste estudo foi avaliar o efeito da densidade e do teor de extrativos na variação da
cor da madeira de teca (Tectona grandis L. f.) proveniente de plantios de diferentes espaçamentos.
As análises colorimétricas foram realizadas nas faces radial e tangencial das madeiras de cerne
e alburno com o espectrofotômetro CM 2600d no espaço de cor L*a*b*. A densidade e o teor de
extrativos foram determinados segundo as normas ASTM D2395 e ASTM D1105. A madeira do
maior espaçamento de plantio apresentou maior densidade e maior teor de extrativos. Na seção
radial, as madeiras de cerne de maior densidade apresentaram mais pigmento amarelo, enquanto
que na seção tangencial elas são mais escuras e apresentam menos pigmento amarelo. As madeiras
de alburno de maior densidade são mais escuras e apresentam mais pigmento vermelho em
ambas as seções. As madeiras mais escuras e com mais pigmento vermelho apresentaram um
maior teor de extrativos.

- by Floresta Ambiente and +1
- •
- Colorimetry, Wood Quality, Colorimetría, qualidade da madeira