Foi avaliada a qualidade de lâminas produzidas com a madeira de paricá (Schizolobium amazonicum). Para tanto, foram observadas propriedades físicas (massa específica, porosidade, teor de umidade e estabilidade dimensional) e mecânicas (resistência à flexão estática e à tração paralela), realizou-se a avaliação não destrutiva por meio Stress Wave, verificou-se a composição química e a caracterização da superfície (análise de imagem, cor, rugosidade e molhabilidade para ambas as faces das lâminas). Os resultados obtidos indicaram ser as lâminas de paricá um material de coloração branco-acinzentada, baixa massa específica, elevada porosidade, baixa estabilidade dimensional, pouca rugosidade e alta molhabilidade. O módulo de elasticidade dinâmico obtido por Stress Wave e a massa específica apresentaram correlação significativa com o desempenho mecânico das lâminas, podendo ser estes parâmetros utilizados como indicadores de resistência nas estratégias de montagem de compostos laminados

Integrated crop-livestock-forest (iCLF) systems are consolidated as alternatives for multiple use of agricultural lands to produce grains, meat, milk, timber and non-timber products. This article reports the analysis of the wood quality of a eucalyptus clone grown in conventional homogenous plantation and iCLF system and evaluated at 7-year age. For this purpose, 12 and 36 trees, respectively, from a conventional plantation and the iCLF system, were collected and sampled to determine their chemical composition (ashes, extractives, total carbohydrates and lignin contents) and physical–mechanical properties. Higher contents of ashes, extractives and holocellulose were found in wood from the iCLF system. Wood from that system had higher density and both static bending and compressive strength. Linear and volumetric shrinkage as well as the anisotropic factor were not influenced by the management system. Despite being juvenile, the wood from iCLF can be employed for industrial uses, notably sawn lumber and firewood.

Objetivou-se avaliar o emprego da colorimetria na caracterização da biodeterioração das madeiras de marupá, jequitibá e cumaru submetidas ao ataque de fungos de podridão branca e parda. Para tanto, corpos de prova de cada espécie amazônica foram submetidos a ensaios de apodrecimento acelerado, de acordo com a American Society for Testing and Materials - ASTM D2017, durante 20 semanas. Os parâmetros colorimétricos L* (luminosidade), a* (coordenada verde-vermelho), b* (coordenada amarelo-azul) e a variação total da cor (∆E) foram determinados semanalmente até a quarta semana, e posteriormente a cada duas semanas até a vigésima semana, com auxílio de um espectrofotocolorímetro. Adicionalmente, foram determinadas as perdas de massa dos corpos de prova. Os resultados permitiram destacar que a colorimetria foi eficaz no monitoramento da biodeterioração da madeira, bem como para diferenciação da podridão branca e parda. As melhores predições da resistência natural aos fungos de podridão branca e parda foram obtidas com os parâmetros b* e L*, respectivamente. Enfatiza-se também, o emprego da ∆E como parâmetro auxiliar na estimativa da biodeterioração da madeira, em razão de suas correlações significativas com a perda de massa.

The great diversity of tropical wood species makes it difficult to obtain information about their technological properties. The present work employed ultrasound to estimate the physical and mechanical properties of four wood species: African mahogany (Khaya senegalensis), ‘freijó’ (Cordia goeldiana), ‘paricá’ (Schizolobium amazonicum), and teak (Tectona grandis). Nineteen-year-old adult trees were selected and harvested from an agroforestry system (AFS) located in the Brazilian Amazon. From the harvested trees, 1.5 m logs were sawn and test specimens were obtained for physical-mechanical assays. The ultrasound propagation speed (V ₀) and the dynamic modulus of elasticity (E _d ) were obtained from applying ultrasound longitudinally in wood samples. Values of V ₀ decreased from the lightest wood (paricá) to the heaviest (African mahogany), and E _d presented the opposite behavior. For the physical properties, the coefficient of determination (R ²) ranged from 12 to 35% and the best linear regression models were fitted for the basic density, having V ₀ and E _d as independent variables. For the mechanical properties, the values of R ² varied from 18 to 63% and higher correlations were found between parallel-to-grain compression strength and E _d , and rigidity, static bending and E_d. Ultrasound presented the potential to estimate the properties of tropical wood species from the ASF.

The present work aimed to evaluate the wood of fourteen genetic materials (nine species, between native and exotic, and five clones of Eucalyptus) cultivated under two post-planting irrigation regimes in the Brazilian semiarid region. For each genotype, six trees (11 years old) were selected and subjected to two initial irrigation regimes (up to 12 months and up to 36 months) after planting. Discs of different stem heights were taken: 0% (base), breast height (DBH), 20%, 40%, 60%, 80%, and 100%. Samples were extracted along the radial axis of each disk at three regions (the pith-adjacent region, intermediate region, and bark-adjacent region). Samples were subsequently saturated in water to determine their density via the water displacement method. The irrigation systems caused changes in the pattern of radial and longitudinal variation in the clones regarding the proportion of woody material in the stem. Among the native species, Angico stood out with a high density and little juvenile wood, and Pau d’arco, with a low density and a high rate of juvenile wood. Among the exotic species, Nim presented a high density and a low rate of juvenile wood, and Chichá presented a high rate of juvenile wood and a low density. In the Eucalyptus hybrids, VE38 stood out with a high density. Overall, there was an influence from irrigation management, observed with greater intensity in exotic species for Mahogany and Acacia and for the VE41 and AEC1528 clones of Eucalyptus. The values of basic densities in the trees varied from 0.35 to 0.85 g·cm⁻³. There was good adaptation of native and exotic species and clones to the planting area in the Semiarid region.