Basic Density

Os objetivos deste estudo foram determinar a variação das propriedades físicas da madeira de
Eucalyptus pellita F. Muell; determinar a variação das dimensões dos elementos anatômicos
da madeira pelo método de aquisição e análise de imagens digitais através do software CELLF
(Olympus®); e determinar as correlações existentes entre as variáveis estudadas. Amostras
não destrutivas (baguetas de 20 mm de diâmetro) foram retiradas de árvores com 15 anos
de idade e dividas em três posições: cerne, transição cerne/alburno e alburno. As análises
estatísticas não indicaram diferenças significativas entre as três posições para nenhuma das
variáveis dependentes estudadas, provavelmente devido à predominância de madeira juvenil. A
densidade básica mostrou estar mais relacionada às dimensões das fibras (comprimento, largura
e espessura de parede) do que aos demais elementos anatômicos. A contração volumétrica
tendeu a diminuir com o aumento da largura dos raios e com a redução do comprimento dos
vasos, sendo pouco afetada pelos demais elementos anatômicos.

Field trials testing a total of 27 clones of the interspecific hybrid Acacia mangium × A. auriculiformis and seedling controls of the parental species were established at Ba Vi and Yen Thanh in the north of Vietnam and Long Thanh in the south. At both Ba Vi and Yen Thanh there were significant (P < 0.001) differences in height and diameter at breast height (DBH) among 22 tested clones at 4 years. At Long Thanh, twelve hybrid clones did not differ significantly in DBH at age 3 years, but did (P < 0.001) at age 5 years. At the two northern sites the acacia hybrid clones had significantly greater DBH than control seedlots of the parental species. At Long Thanh, DBH of the hybrid clones and A. mangium was similar, with a genetically improved seedlot of A. mangium displaying the best DBH. Mean wood basic density at breast height of the acacia hybrid clones was 539 kg m−3 at Yen Thanh at age 8 years, and 473 kg m−3 at Long Thanh at age 5 years; density for A. mangium at Long Thanh was only slightly lower than the hybrid clones at 461 kg m−3. Linear regressions of Pilodyn penetration (PP) at breast height on wood basic density explained 60% of the variance in density of treatments (clones and control seedlots) at Yen Thanh and 36% at Long Thanh. There were significant differences between hybrid clones in PP at all three trial sites. Clonal DBH performance was not strongly correlated across the three trial sites; Pearson correlations of clone mean DBH between pairs of sites ranged from −0.47 to 0.20. Clonal rankings for PP were more stable, with Pearson correlations between pairs of sites ranging from r = 0.71 to 0.78.

The main objective of this paper was to estimate the wood basic density (DB) and the resistance to the per- foration of seven 16-years-old Eucalyptus clones, experimentally planted at Aracruz, Espirito Santo State, Brazil. For this, the trees stems were perforated at the DBH level, following the determination of the wood basic density of discs cut at the same position.

Neste trabalho, investigou-se a variação da densidade básica, dos constituintes químicos e das características anatômicas em função da classe de diâmetro (superior, mediana e inferior) e posição radial nas árvores de uma população de Eucalyptus umbra, de 25 anos de idade. Apenas o comprimento das fibras variou entre as classes de diâmetro. Fibras mais longas ocorreram na classe superior e fibras mais curtas, na classe inferior. Os resultados mostram a homogeneidade da madeira entre as classes de diâmetro. A largura e a frequência de raio, bem como o teor de lignina, não foram influenciadas significativamente pela posição radial. O comprimento de fibras e os elementos de vaso, assim como o diâmetro dos vasos, aumentaram significativamente no sentido medula-casca. A partir das análises de regressão, concluiu-se que a variação radial é decorrente da maturação do câmbio vascular e da transição de lenho juvenil para lenho adulto.

One hundred and forty families from 13 provenances of Acacia auriculiformis A. Cunn ex Benth were tested in a progeny trial in Ba Vi, Ha Tay Province, on a typical hill site in northern Vietnam. Two selective thinnings were done, at 3 and 5 years, to retain only the best tree in each four-tree family plot. All remaining trees were

Genetic parameters for stem diameter and wood density were compared at selection (4–5 years) and harvest (16–17 years) age in an open-pollinated progeny trial of Eucalyptus globulus in Tasmania (Australia). The study examined 514 families collected from 17 subraces of E. globulus. Wood density was assessed on a subsample of trees indirectly using pilodyn penetration at both ages and directly by core

OSB Panels of mixtures of clones of Eucalyptus spp were produced, using alternative types of PMUF and MUF resin. The average basic density of the studied clones was 0.56 g/cm3. The dimensions of particles were 85mm length, 20mm width and 0.60mm thickness. The nominal density of the produced panels was 0.70 g/cm3. According to the conditions in which this work

• Vène wood (Pterocarpus erinaceus Poir.) is currently the favorite wood for manufacture of xylophone in Mali. A dynamic analysis method with free boundary conditions, known as BING, was used to determine the main acoustic properties: specific dynamic modulus (E L /ρ), damping coefficient or internal friction (tan δ), sound radiation coefficient (SRC) and peak response (PR). • The aim was to investigate the acoustic properties of vène wood (1) along three radial locations (internal: IHW, median: MHW, external: EHW); (2) related to two geographic origins (Guinean and Soudanian areas); and (3) to investigate the effect of ring width (RW), basic density (D b ) and extractive content (EC) on these properties. • High correlations were shown between tanδ with E L /ρ and EC. tan δ decrease with increasing E L /ρ or EC. No significant difference of SRC was found between the geographic areas and the radial locations. No correlation between RW and acoustic properties was observed. E L , E L /ρ and PR were significantly higher for wood from the Guinean area than from the Soudanian area and also higher for EHW and MHW than for IHW. tan δ follows inverse trends. These results could explain why the Malian xylophone makers empirically use only the wood from EHW and MHW.

The wood quality of the Eucalyptus clones was evaluated by their physical, chemical, mechanical charac- teristic and fiber dimensions, looking for define their best form of use. The results showed that exist poten - tial of multiple application for the studied clones. Clones 5, 7, 9, 10 and 11 present potential to be used as solid wood; clones 1, 2

Data taken from 261 4-year-old trees growing within a nationwide set of site quality plots where Pinus radiata D. Don and Cupressus lusitanica Mill. were established at high stand densities (40,000stemsha−1) were analysed to (i) determine how site, species and fertilisation influence the wood properties basic density and green dynamic modulus of elasticity (MOE) for the stem at the tree

The relationships between growth characteristics and wood properties were investigated for a threatened species, Pericopsis mooniana, to promote the establishment of plantations of this species in the tropics. Growth charac-teristics (diameter and height) and stress-wave ...