scholarly journals INFLUÊNCIA DA IDADE E DA POSIÇÃO RADIAL NA MASSA ESPECÍFICA DA MADEIRA DE Eucalyptus grandis Hill ex. MAIDEN

FLORESTA ◽  
2004 ◽  
Vol 34 (1) ◽  
Author(s):  
José De Castro Silva ◽  
José Tarcísio Da Silva Oliveira ◽  
Mário Tomazello Filho ◽  
Sidon Keinert Júnior ◽  
Jorge Luis Monteiro De Matos
Keyword(s):  
Specific Gravity ◽  
Eucalyptus Grandis ◽  
Radial Position ◽  
Wood Specific Gravity ◽  
Old Trees

Este trabalho objetivou avaliar a variação da massa específica da madeira de Eucalyptus grandis, de quatro idades em diferentes posições radiais. Para os ensaios de massa específica básica e aparente, as amostras foram retiradas de seções radiais de três discos, retirados da base e do final da primeira e da segunda toras, com comprimentos comerciais de três metros, tomando-se quatro posições eqüidistantes (0, 33, 66 e 100%), no sentido medula-casca. Para o ensaio de densitometria de raios-X, as amostras foram retiradas dos mesmos discos, utilizando-se-se toda a seção radial. Em todos os ensaios, verificou-se que a madeira de dez anos apresentou os menores valores de massa específica, seguida da madeira de quatorze anos. Os maiores valores de massa específica foram encontrados na madeira de vinte anos, seguida da madeira de vinte e cinco anos. Em todas as idades, verificou-se um crescimento dos valores de massa específica no sentido radial medula-casca. Os resultados obtidos com a análise densitométrica foram semelhantes aos dados apresentados na análise de massa específica aparente. INFLUENCE OF AGE AND RADIAL POSITION ON THE DENSITY OF THE WOOD OF Eucalyptus grandis HILL EX. MAIDEN Abstract The objective of this work was to evaluate the variation of wood specific gravity of Eucalyptus grandis of four ages and radial positions. Specific gravity samples were taken radial disks in the bark-to-pith direction at 0, 33, 66 and 100% of the radii. For the densitometry study samples were collected radially from disks at three positions of the stem. It was observed in all cases that 10-year-old trees had the lowest values of specific gravity, fourteen-year-old trees came second. Heaviest wood was found in 20-year-old trees, while the older (25-year) trees were a little lighter. It was found in all ages, that specific gravity increased from the pith to the bark.

Assessing specific gravity of young Eucalyptus plantation trees using a resistance drilling technique

Holzforschung ◽  
2017 ◽  
Vol 71 (2) ◽  
pp. 137-145 ◽  
Author(s):  
José Tarcísio da Silva Oliveira ◽  
Xiping Wang ◽  
Graziela Baptista Vidaurre
Keyword(s):  
Specific Gravity ◽  
Eucalyptus Grandis ◽  
Clear Trend ◽  
Eucalyptus Plantation ◽  
Breast Height ◽  
Average Resistance ◽  
Drilling Technique ◽  
Resistance Drilling ◽  
Old Trees ◽  
The Relationship

Abstract The resistance drilling technique has been in focus for assessing the specific gravity (SG) of young Eucalyptus trees from plantations for pulpwood production. Namely, the data of 50 34-month-old and 50 62-month-old trees from Eucalyptus grandis×Eucalyptus urophylla clonal plantations was evaluated, while the relative resistance profiles were collected with the amplitude in a scale from 0 to 100% of each tree at the breast height. For laboratory determination of SG and moisture content (MC), 3-cm-thick disks were taken at breast height. The average resistance amplitude of a full drill penetration or a half-diameter penetration showed weak correlations with SG for both 34-month-old and 62-month-old trees. However, when the two age classes were combined, the strength of the relationship was improved significantly, with a correlation coefficient ranging from 0.71 to 0.77 with respect to SG determined from strip samples and from 0.59 to 0.72 with respect to SG determined from wedge samples. The drill penetration depth had a significant effect on the relationship between average amplitude and SG. A clear trend of weakening correlation was observed with increasing drill penetration. As a result, the average resistance amplitude of a half-diameter drilling (from bark-to-pith) is more advantageous for assessing the SG of young Eucalyptus trees than a whole-diameter drilling.

scholarly journals MASSA ESPECÍFICA E RETRATIBILIDADE DA MADEIRA DE SEIS ESPÉCIES DE EUCALIPTO CULTIVADAS NO LITORAL DE SANTA CATARINA

FLORESTA ◽  
2014 ◽  
Vol 45 (2) ◽  
pp. 329
Author(s):  
Jackson Roberto Eleotério ◽  
Douglas Reichert ◽  
Kerling Fabiane Hornburg ◽  
Isalena Meneguelli
Keyword(s):  
Specific Gravity ◽  
Eucalyptus Grandis ◽  
Volumetric Shrinkage ◽  
North Coast ◽  
Eucalyptus Urophylla ◽  
Santa Catarina ◽  
Eucalyptus Pilularis ◽  
Eucalyptus Cloeziana ◽  
Old Trees ◽  
Shrinkage Coefficient

O objetivo deste trabalho é determinar e comparar a massa específica básica e aparente a 12% de umidade e os coeficientes de contração radial, tangencial e volumétrico de cinco espécies e um híbrido de eucalipto. As amostras de Corymbia torelliana, Eucalyptus cloeziana, Eucalyptus pilularis e Eucalyptus resinifera foram retiradas de árvores com 17 anos; as de Eucalyptus grandis, de árvores com 14 anos; e as de Eucalyptus grandis x Eucalyptus urophylla, de árvores com oito anos, todas plantadas no litoral norte de Santa Catarina. A madeira do híbrido Eucalyptus grandis x Eucalyptus urophylla e a de Eucalyptus grandis e de Eucalyptus pilularis classificam-se como leve, e a das demais espécies é classificada como madeira moderadamente pesada. Independentemente da contração analisada, os grupos formados na comparação de médias foram os mesmos. Os coeficientes de contração radial de Eucalyptus cloeziana e Eucalyptus resinifera são altos; já os coeficientes de contração tangencial e volumétrico de Eucalyptus grandis e volumétrico de Eucalyptus pilularis são baixos; e os demais podem ser classificados como médios. A variação na massa específica não é acompanhada de proporcional variação nos coeficientes de contração, resultando em baixas e moderadas correlações entre essas variáveis, apesar de significativas.Palavras-chave: Propriedades físicas; contração; Eucalyptus; Corymbia. AbstractSpecific gravity and shrinkage coefficients of wood of six species of eucalypts cultivated on the coast of Santa Catarina. This work aims at determining and comparing the basic and 12% moisture content specific gravity and radial, tangential and volumetric shrinkage coefficients of five species and a hybrid of eucalypts. The samples of Corymbia torelliana, Eucalyptus cloeziana, Eucalyptus pilularis, Eucalyptus resinifera were extracted from 17 years old trees; ones of Eucalyptus grandis from 14 years old trees and the ones of Eucalyptus grandis x Eucalyptus urophylla from eight years old trees, all of them planted on the North Coast of Santa Catarina State. The wood of the hybrid Eucalyptus grandis x Eucalyptus urophylla, of the Eucalyptus grandis and of the Eucalyptus pilularis can be classified as light, the others can be classified as moderately heavy. Independently on the shrinkage analyzed, the groups formed during the multiple mean comparing are the same. The radial shrinkage coefficient of Eucalyptus cloeziana and that of Eucalyptus resinifera are high. However, the tangential and volumetric shrinkage coefficients of Eucalyptus grandis and the volumetric shrinkage coefficient of Eucalyptus pilularis are low; the others can be classified as medium. The variation on specific gravity is not followed by proportional variation on the shrinkage coefficients, resulting in low and moderate correlations between coefficients even tough significant.Keywords: Physical properties; shrinkage coefficients; Eucalyptus; Corymbia.

scholarly journals WOOD DENSITY OF CLONES OF Eucalyptus urophylla x Eucalyptus grandis IN DIFFERENT CONDITIONS OF GROWTH

FLORESTA ◽  
2014 ◽  
Vol 45 (1) ◽  
pp. 193 ◽  
Author(s):  
Renata Mauri ◽  
José Tarcísio da Silva Oliveira ◽  
Mário Tomazello Filho ◽  
Antônio Marcos Rosado ◽  
Juarez Benigno Paes ◽  
...  
Keyword(s):  
Specific Gravity ◽  
Sampling Method ◽  
Wood Quality ◽  
Genetic Material ◽  
Eucalyptus Grandis ◽  
Growth Conditions ◽  
Eucalyptus Urophylla ◽  
Growth Site ◽  
Wood Specific Gravity

AbstractVariations in the growth site of trees have influence on the internal structure of the trunk. Considering this fact, this study investigated influence of the characteristics of the growth site on wood specific gravity of two clones of Eucalyptus urophyllax Eucalyptus grandis,  approximately six years old, growing in different altitudes and topographies. Furthemore, two methods of sampling of the wood specific gravity were studied, for comparison purpose. Results showed that wood specific gravity underwent variations between growth conditions andtrends in wood specific gravity variations, compared between growth conditions, were the same regardless of the clone. With relation to  sampling method, the wedge was more appropriate for determination of wood specific gravity, in order to extrapolate the disc density. These results provide tools to forestry companies about consolidation of genetic material and its behavior in different growth conditions, to attend wood quality requirements.Keywords: Eucalypt; wood quality;topography; altitude. ResumoDensidade do lenho de clones de Eucalyptus urophylla x Eucalyptus grandis em diferentes condições de crescimento. As variações nas características do local de crescimento das árvores apresentam influência na estrutura interna do tronco. Diante deste fato, foi estudada a influência das características do local de crescimento na densidade básica da madeira de dois clones de EucalyptusurophyllaxEucalyptusgrandis, com aproximadamente seis anos de idade que cresceram emaltitudes e topografias diferentes. Além disso, estudou-se duas formas de amostragem da densidade básica na árvore para fins de comparações. Por meio dos resultados pode-seobservar que a densidade básica da madeira sofreu variações nas diferentes condições de crescimento e que as tendências de variações na densidade básica da madeira, frente às condições de crescimento, foram as mesmas independentemente do clone. Em relaçãoao método de amostragem,a cunha mostrou-se mais apropriada para determinação da densidade básica da madeira para fins de extrapolação da densidade do disco.Estes resultados fornecem subsídios para as empresas do setor florestal no que diz respeito à consolidação de material genético e seu comportamento em diferentes condições de crescimento para atender suas demandas de qualidade de madeira.Palavras-chave:Eucalipto; qualidade de madeira;topografia; altitude.

Wood Specific Gravity in Species from Two Tropical Forests in Mexico

IAWA Journal ◽  
1987 ◽  
Vol 8 (2) ◽  
pp. 143-148 ◽  
Author(s):  
Josefina Barajas-Morales
Keyword(s):  
Specific Gravity ◽  
Tropical Forests ◽  
Tropical Rainforest ◽  
Deciduous Forest ◽  
Woody Species ◽  
T Test ◽  
Tropical Deciduous Forest ◽  
Wood Specific Gravity ◽  
Dry Deciduous Forest

The specific gravity of 220 woody species, half of them from a tropical rainforest, half from a tropical deciduous forest was measured. The two groups were compared using a Student t-test. The results show highly significant differences in specific gravity between the species from the two areas: woods from the dry deciduous forest tend to be much heavier than those from the rainforest.

Heartwood decay resistance by vertical and radial position in Douglas-fir trees from a young stand

1999 ◽  
Vol 29 (12) ◽  
pp. 1993-1996 ◽  
Author(s):  
Barbara L Gartner ◽  
Jeffrey J Morrell ◽  
Camille M Freitag ◽  
Rachel Spicer
Keyword(s):  
Leaf Area ◽  
Decay Resistance ◽  
Douglas Fir ◽  
Radial Position ◽  
Sapwood Area ◽  
Decay Fungus ◽  
Postia Placenta ◽  
Young Stand ◽  
Wide Range ◽  
Old Trees

Heartwood durability of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) was studied as a function of vertical and radial position in boles of trees with a wide range of leaf area/sapwood area ratios. Six 34-year-old trees were harvested from each of three plots established 14 years before: very dense, thinned, and thinned and fertilized. Heartwood samples from three radial positions and five heights were incubated with the decay fungus Postia placenta (Fr.) M. Larsen et Lombard. There were no significant differences in wood mass loss (decay resistance) by vertical or radial position. One could expect that trees with high leaf area/sapwood area could have the carbon to produce heartwood that is more resistant to decay than trees with lower leaf area/sapwood area. However, we found no relationship between leaf area above node 20, sapwood area there, or their ratio, and the decay resistance of outer heartwood at that node. These results suggest that, for young Douglas-fir trees, heartwood durability does not vary with position in the bole or with environments that alter the tree's balance of sapwood and leaf area. We suggest that young stands may thus be robust with respect to the effect of silvicultural regimes on heartwood durability.

Within-Tree Variation in Wood Fibre Biometry And Basic Density of the Urograndis Eucalypt Hybrid (Eucalyptus Grandis × E. Urophylla)

IAWA Journal ◽  
2006 ◽  
Vol 27 (3) ◽  
pp. 243-254 ◽  
Author(s):  
Teresa Quilhó ◽  
Isabel Miranda ◽  
Helena Pereira
Keyword(s):  
Wall Thickness ◽  
Fibre Length ◽  
Eucalyptus Grandis ◽  
Basic Density ◽  
Wood Properties ◽  
Axial Variation ◽  
Average Fibre ◽  
Length Width ◽  
Hybrid Eucalyptus ◽  
Old Trees

Within-tree variations in fibre length, width, wall thickness and wood basic density of Eucalyptus grandis × E. urophylla (urograndis) were studied in five 6.8-yr-old seedling trees and five 5.6-yr-old trees from one clone from Brazil. Samples were taken at 5%, 25%, 35%, 55%, 65% and 90% of stem height and five radial positions (10%, 30%, 50%, 70% and 90% of radius). The tree average fibre length, width and wall thickness were in seed and clone trees: 0.955 mm and 1.064 mm, 18 μm and 20 μm, 3.6 μm and 4.4 μm respectively. The axial variation of fibre dimensions was very low, while there was a consistent but small increasing trend from pith to periphery. The basic density ranged from 397–464 kg/m3 to 486–495 kg/m3 respectively in seedling and clone trees with a low variation along the stem. In comparison with other eucalypt pulpwood, e.g. E. globulus, the urograndis hybrid showed similar fibre dimensions and lower basic density. Overall the within-tree variation of these wood properties was low and age had a small impact on the variation of density and fibre dimensions.

scholarly journals Pan tropical biomass equations for Mexico's dry forests

2014 ◽  
Vol 32 (3) ◽  
pp. 367-376 ◽  
Author(s):  
José Návar
Keyword(s):  
Specific Gravity ◽  
Stand Structure ◽  
Gravity Data ◽  
Theoretical Models ◽  
Tropical Dry Forests ◽  
Large Sample Size ◽  
Dry Forests ◽  
Wood Specific Gravity ◽  
Spatial Coverage ◽  
Ecological Importance

This study reports a set of robust regional M-tree allometric equations for Mexico's tropical dry forests and their application to a forest inventory dataset for the States of Durango and Sinaloa, Mexico. Calculated M data from 15 reported equations were fitted, applied and validated for regional and global models. Proposed theoretical models, empirically derived equations, as well as global and local reported equations were fitted and applied to calculated M-tree data using wood specific gravity, diameter at breast height, and top height as exogenous variables. Empirically-derived, computer-based equations assessed the M-tree evaluations slightly better than the theoretical, the global and the local models. However, the theoretical models projected compatible M-tree values and deserve further attention once wood specific gravity data are collected in the field. Using the best fit equation, mean M plot density values of 30, 41 and 35 Mg ha-1 were estimated from 57 plots (1,600 m2 each), 217 plots (1,000 m2 each) and 166 plots (1,000 m2 each) in the tropical dry forests of the States of Durango, Tiniaquis and Vado Hondo (Sinaloa), respectively. The large sample size, the richness of the tested allometric models, the economic and ecological importance of this data-source, and the spatial coverage of these equations made this dataset uniquely useful for biomass, charcoal, and other bio-energy estimations, as well as for understanding the inherent heterogeneity of the stand-structure in dynamic tropical forest environments.

scholarly journals DETERMINAÇÃO DAS PROPRIEDADES ENERGÉTICAS DA MADEIRA E DO CARVÃO VEGETAL PRODUZIDO A PARTIR DE Eucalyptus benthamii

FLORESTA ◽  
2014 ◽  
Vol 45 (1) ◽  
pp. 57 ◽  
Author(s):  
Daniela Letícia Nones ◽  
Martha Andreia Brand ◽  
Alexsandro Bayestorff Da Cunha ◽  
Adriel Furtado De Carvalho ◽  
Solange Maria Krug Weise
Keyword(s):  
Chemical Analysis ◽  
Specific Gravity ◽  
Calorific Value ◽  
Biomass Energy ◽  
Energetic Properties ◽  
Different Ages ◽  
End Use ◽  
Immediate Analysis ◽  
Old Trees ◽  
Volumetric Yield

Este trabalho teve como objetivo caracterizar energeticamente a madeira e o carvão vegetal obtidos a partir da espécie Eucalyptus benthamii Maiden & Cambage para duas diferentes idades, 5 e 13 anos. Para a madeira de cada idade, foram confeccionados 48 corpos de prova, com aproximadamente 2 x 2 x 2 cm, que foram utilizados para determinação da massa específica, poder calorífico superior, análise química imediata e carbonização. Após a carbonização, as propriedades energéticas do carvão vegetal foram avaliadas a partir da massa específica aparente, rendimento gravimétrico e volumétrico, poder calorífico superior e análise química imediata. Tanto para a madeira quanto para o carvão vegetal houve influência da idade. A madeira com 13 anos apresentou maior massa específica básica e maior poder calorífico. Porém as diferenças nas propriedades físicas e energéticas da madeira das duas idades não justificam a manutenção da floresta até os 13 anos de idade, quando seu uso final é a geração de energia na forma de carvão. Em relação ao carvão, aquele produzido com madeira de 13 anos apresentou maior rendimento, enquanto o carvão vegetal de 5 anos apresentou melhor qualidade final para uso energético.Palavras-chave: Energia de biomassa; propriedades energéticas; eucalipto. AbstractDetermination of energetic properties of wood and charcoal produced from Eucalyptus benthamii. This research aimed to characterize the energetic properties of wood and charcoal obtained from Eucalyptus benthamii for two different ages, 5 and 13 years. For each timber age, we prepared 48 specimens, approximately 2 x 2 x 2 cm, used to determine specific gravity, calorific value, immediate analysis and carbonization. After carbonization, we evaluated the energetic properties of the charcoal in relation to density, gravimetric and volumetric yield, calorific value and immediate chemical analysis. As the wood as charcoal were influenced by age. The 13 years old timber revealed higher specific gravity and higher calorific value. However, the differences in the physical and energetic properties of the wood of the two ages do not justify maintaining the forest until the age of 13, as its end use is generation of energy as coal. The charcoal produced from 13 years old trees had the highest yield, while the charcoal from 5 years old trees had better quality to energy usage.Keywords: Biomass energy; energy properties; Eucalyptus.

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