RESUMO Atualmente, há grande demanda por madeira de árvores de espécies tropicais, como a de Schizolobium parahyba var. amazonicum, sendo escassa a literatura sobre as condições de crescimento e a ...qualidade do seu lenho. Este trabalho analisa a estrutura anatômica e o perfil radial de densidade aparente do lenho de árvores de S. Parahyba var. amazonicum, da Reserva Experimental Catuaba (REC) e do Parque Zoobotânico (PZ) da Universidade Federal do Acre (UFAC), no Estado do Acre. Amostras do lenho do tronco das árvores foram extraídas para a análise anatômica, por densitometria de raios X, e a determinação da sua idade. Os resultados indicaram que o lenho das árvores de Schizolobium amazonicum coletado nas áreas do PZ apresentaram maior proporção de madeira adulta em relação à juvenil, pela idade mais avançada (22-33 anos), e maior diâmetro do tronco em relação às árvores da REC (10-18 anos). A caracterização anatômica e a delimitação da área de madeira juvenil-adulta do tronco das árvores permitiram indicar o uso múltiplo e sustentado da sua madeira.
PREMISE OF THE STUDY:
Wood density is the top predictor of growth and mortality rates (vital rates) but with modest explanatory power at best. Stronger links to vital rates are expected if wood ...density is decomposed into its anatomical properties at sapling and adult stages, since saplings and adults differ in wood traits and vital rates. We examined whether anatomical determinants of wood density and strength of the relationship between wood traits and vital rates shift between saplings and adults.
METHODS:
Using wood segments from near pith (sapling) and near bark (adult) for 20 tree species (three adults each) from Barro Colorado Island, Panama, we quantified wood traits. Vital rates for saplings and adults were obtained from an earlier study.
KEY RESULTS:
Anatomical predictors of wood density were similar for sapling and adult wood, with wood density variation largely explained by fiber lumen area and fiber wall fraction. In sapling wood only, growth rates decreased with fiber wall fraction and increased with fiber lumen area, while mortality rates increased with vessel area but decreased with fiber wall fraction and vessel density.
CONCLUSIONS:
Wood traits of sapling trees provide functional insight into the growth–mortality tradeoff. Sapling wood with relatively large fiber lumen area and wide vessels, enabling faster hydraulic transport but less mechanical strength, is associated with fast growth and high mortality. Sapling wood with relatively more fiber wall and many narrow vessels, enabling greater mechanical strength but slower hydraulic transport, is associated with slow growth and low mortality.
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The present study examined the wood properties of Pterocarpus erinaceus, a species found in West Africa's Guineo-Sudanian and Sudano-Sahelian zones. The primarily focus was on wood fiber properties, ...which serve as indicators of cambial growth and the transition between juvenile and mature wood. The aim was to analyze the factors contributing to the variability of the wood fiber properties. Specifically, it examined the effect of cambial age and ecological factors on fiber properties and analyzed how the fiber properties influence density and dimensional characteristics of the wood. Measurements of fiber properties were obtained from 451 specimens collected in the Guinean, Sudanian, and Sahelian zones in Burkina Faso, Niger, and Togo. The results indicate significant variations in average fiber parameters among the three climatic zones. This variability leads to an increase in the length, width, and thickness of the fibers along the north-south decreasing rainfall gradient. However, no noteworthy correlations were observed between cambial age and fiber properties, posing challenges in distinguishing between juvenile and adult wood. In terms of correlation, the analysis shows that fiber length has no effect on physical properties, but fiber width significantly influences basic density, wood shrinkage, and the fiber saturation point (FSP).
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The anatomical changes occurring during transition from juvenile to mature wood were studied in the branch and main trunk of Leucaena leucocephala. To confirm the wood maturity in the 5-yr-old tree, ...the anatomical features were compared with the adult wood collected from the main trunk of a 15-yr-old tree. In both the branch and wood of the trunk, most of the anatomical features—such as increase in dimensions of fibers and vessel elements, and decrease in frequency of vessel elements and rays—were gradual during radial growth from pith to periphery. A noticeable anatomical change is observed in the transition of triseriate rays to multiseriate rays in the region of wood which is about 5.5 cm away from the pith. The ray dimensions and anatomical features of other elements from the periphery of the branch and 5-yr-old trunk xylem match with that of 15-yr-old main trunk wood. This indicates that in both the branches and main trunk of Leucaena, transition from juvenile to adult or mature wood occurs after the trees have attained 14 cm radial growth.
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5.
잣나무와 일본잎갈나무 수지구의 출현형태 김남훈; Nam Hun Kim; 권성민 ...
목재공학,
01/2006, Volume:
34, Issue:
1
Journal Article
Peer reviewed
Open access
Radial variations of resin canals in Pinus koraicnsis and Larix kaempferi which were cultivated-commercial trees in Korea, were examined to understand the characteristics of wood with light ...microscopy. Both species showed significant differences in the number of vertical resin canals along the radial direction from pith to bark. In Larix kaempferi, the diameters of horizontal resin canals and the number of epithelial cells showed a clear variation in radial direction. Namely, significant differences in the characteristics of the resin canals and epithelial cells were found in juvenile and adult woods. Consequently, it was concluded that the characteristics of resin canals can he used to estimate the wood quality. 국내에 가장 많이 조림된 수종이고 중요한 국산 목재자원인 잣나무와 일본잎갈나무 두 수종의 재질특성을 구명하기 위하여 수지구와 에피델리얼세포의 수간내 변이성을 조사하였다. 그 결과, 두 수종 간에 수직수지구의 수와 그 수의 방사방향 변이성에 차이가 있었다. 일본잎갈나무의 수평수지구의 직경 및 에피델리얼세포 수도 방사방향으로 변이성을 나타냈다. 즉 미성숙재부와 성숙재부간에 수지구와 에피델리얼 세포의 출현특성이 차이가 있었다. 결론적으로, 잣나무와 일본잎갈나무에 있어서 수지구와 에피델리얼세포의 출현특성을 성숙재부와 미성숙재부로 구분하는 재질지표로 이용할 수 있을 것으로 생각하였다.
Com o objetivo de analisar a variação anatômica ao longo do caule de Terminalia ivorensis, estudaram-se amostras de madeira de três indivíduos, nos planos radial e axial. Para tal, corpos de prova ...foram obtidos a partir de discos de madeira, de 2 em 2cm, no sentido medula-câmbio. A metodologia usada para desenvolver o trabalho foi aquela tradicionalmente recomendada para estudos em anatomia vegetal. A descrição anatômica realizada seguiu as recomendações do IAWA Committee. No sentido radial do caule, alguns elementos anatômicos apresentaram tendências de variação definidas e significativas estatisticamente quando aplicado o teste Tukey para comparação de médias. São eles: freqüência, diâmetro e comprimento dos elementos de vaso, freqüência de raios/mm linear, comprimento dos raios em número de células, e comprimento e espessura da parede das fibras. Já no sentido axial, todas as variáveis analisadas não se mostraram estatisticamente significativas. Os resultados observados devemse, principalmente, à caracterização bem definida dos lenhos juvenil e adulto na madeira de Terminalia ivorensis.
In order to verify anatomical stem variation of the Terminalia ivorensis wood, were studied wood samples at three different heights in the radial and axial planes. Proof bodies were gotten at a 2cm interval from the pith towards the vascular cambium. The utilized methodology to develop the job followed the traditionally recommended methodology for vegetable anatomy studies. The anatomical description followed the recommendations of the IAWA Committee. In the radial stem direction, some anatomic elements showed a well defined trend, which are statistically significant when using the Tukey test for measures comparison. They were: frequency, diameter and length of the vessel elements, ray frequency/linear mm, length of rays in number of the cells and fiber length and thickness. On the other side, in the axial stem direction, was not found anything statistically significant. This results were observed principally due the clear presence of the juvenile and adult wood in the lumber of Terminalia ivorensis.
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