ABSTRACT Background: The fibres dimensions vary along a tree trunk, and these variations are related to the apical meristem and vascular cambium activities; understanding these variations would guide the best use of wood. There have been studies on the pattern of fibres dimensions variation along the tree trunk in the radial and longitudinal directions; however, the vast majority do not take into account the structure of the annual growth rings. Hence, this study aimed to obtain the pattern of fibres dimensions variation and their quality indexes along the tree trunk take into account the structure of the annual growth rings. Two Eucalyptus urophylla x Eucalyptus grandis hybrid clones were used in the study. Ten-year-old trees were selected and discs were removed from 13 longitudinal positions. The disks were prepared and the growth rings were subsequently identified and the samples used for maceration were collected. Twenty fibres were measured in the annual growth rings present in each longitudinal position. Results: In the longitudinal direction, within the annual growth rings, the fibre dimensions and their quality indices did not show a well-defined pattern of variation. In the radial direction, the length, cell wall thickness, wall fraction, and Runkel ratio of the fibres tended to increase following the pith-bark direction, while the lumen diameter and flexibility coefficient decreased. Conclusion: Nevertheless, the fibre width and fibre slenderness index did not present a well-defined pattern of variation in the radial direction.

Resumo As funções de afilamento são ferramentas úteis para estimar diâmetros de toras e volumes comerciais de madeira a quaisquer alturas, sendo de grande importância para os empreendimentos florestais que buscam a otimização do uso de suas florestas. Este trabalho teve como objetivo avaliar modelos de afilamento segmentados, não segmentados e modelos de forma variável para estudo do afilamento do tronco de árvores de Eucalyptus sp. Com uma base de dados proveniente de um plantio de Eucalyptus sp. localizado no sul do estado de São Paulo aos 6,3 anos de idade, os modelos de afilamento testados foram: os modelos não segmentados de Ormerod (1973) e de Schöepfer (1966), o modelo segmentado de Max e Burkhart (1976), e os modelos de forma variável de Muhairwe (1999), Methol (2001) apud Rachid et al. (2014) e de Kozak (2004). Os volumes reais foram calculados utilizando-se o método de Smalian. O modelo de Kozak (2004) obteve as melhores medidas de precisão para estimativa dos diâmetros, já a equação de Muhairwe (1999) demonstrou os melhores resultados gráficos de dispersão de resíduos para a mesma estimativa. Para a estimativa volumétrica, a equação que obteve os melhores resultados foi a proposta por Methol (2001) apud Rachid et al. (2014), com as melhores medidas de precisão e melhor comportamento gráfico, com menores tendências e dispersão mais concentrada dos resíduos.

Abstract Taper functions are useful tools for estimating log diameters and commercial wood volumes at any height, being of great importance to forestry enterprises that aim to optimize the use of their forests. Thus, the aim of this work was to evaluate segmented, non-segmented and variable-exponent taper models for studying the trunk taper of Eucalyptus sp. With a database from a 6.3-year-old Eucalyptus sp. planted forest, in the south of the state of São Paulo, the taper models tested were: the non-segmented models of Schöepfer (1966) and Ormerod (1973) the segmented model of Max and Burkhart (1976), and the variable-exponent models of Muhairwe (1999), Methol (2001) apud Rachid et al. (2014) and Kozak (2004). Real volumes were calculated using the Smalian formula. The equation proposed by Kozak (2004) obtained the best accuracy to estimate the diameters, whereas the Muhairwe (1999) equation showed the best graphic dispersion results for the same estimate. For volume estimation, the equation that obtained the best results was that proposed by Methol (2001) apudRachid et al. (2014), with the best measures of precision and better graphical behavior, with smaller trends and more concentrated dispersion of the residues.

Abstract: This study aimed to determine the wood density using destructive and non-destructive sampling methods in a eucalypt hybrid clonal and determine the best point for the non-destructive sampling of the tree. A 5,6-year-oldEucalyptus urophylla x Eucalyptus grandis hybrid clone, from an energetic forest, was used, planted in the municipal district of Martinho Campos, MG, Brazil. The trees were sampled by three methods of destructive sampling. The traditional method (0%, 25%, 50%,75% and 100% of the commercial height Hc); alternative method (2%, 10%, 30% and 70% Hc) and via a meter by meter method starting from a height of 1,30 m from the soil (DBH). Three non-destructive sampling methods were also appraised: Resistograph®, Pilodyn® and 22 mm diameter cores at a DBH. The use of the Resistograph® at the 1,10 m or 1,50 m points and the Pilodyn® at 1,50m of height from the soil results the best correlations with the basic density determined by the three destructive sampling methods considered.

ABSTRACT The aim of this study was to apply geostatistics to predict the spatial pattern of variations in moisture content of eucalyptus wood chip piles to generate subsidies for adequate sampling and material handling. Wood chip piles were installed in three different storage cycles using newly cut material for 7, 30, and 60 days. Sampling was performed in axial (top, middle, and base) and lateral positions, so that all samples were georeferenced in relation to the distance from the ground and the center of the pile. Moisture values were submitted to geostatistical analysis and kriging. The results confirmed the spatial dependence of moisture content over the piles stored at 7 and 30 days; however, the effect of rainfall was crucial to reduce the spatial dependence of moisture content. The results showed that geostatistics is a useful tool for the creation of reliable sampling protocols.

A diversificada e importante aplicação do lenho das plantações de eucalipto de rápido crescimento exige a análise do efeito dos fertilizantes minerais na qualidade do lenho. Dessa forma, objetivou-se, neste trabalho, avaliar as características anatômicas e a densidade aparente do lenho de árvores de Eucalyptus grandis, plantadas no espaçamento 3m x 2m e fertilizadas com potássio e sódio (no plantio, no 6º e no 12° mês). Foram selecionadas 15 árvores (5 árvores/tratamento) com 6 anos das quais foram cortadas amostras do lenho a 1,3 m de altura (DAP), para a análise das características anatômicas (fibras e vasos) e física (densidade aparente). Os resultados apontaram que as árvores de eucalipto que receberam aplicação de fertilizantes minerais não sofreram alterações significativas na densidade aparente média do lenho, com modelos dos perfis radiais comuns nos três tratamentos, caracterizados pelo aumento dos valores da região próxima à medula em direção à casca. A fertilização mineral influenciou as características anatômicas do lenho das árvores de eucalipto: o tratamento com sódio foi responsável pela diminuição na espessura da parede e pelo aumento no diâmetro do lume; no tratamento com potássio foram detectados vasos de maior diâmetro tangencial.

The diverse and important use of wood from fast growth eucalyptus plantations requires the analysis of the effect of mineral fertilizers on wood quality. The objective of this study was to evaluate the anatomical characteristics and wood density from Eucalyptus grandis trees (3 m x 2 m spacing) fertilized with potassium and sodium (at planting, 6 th and 12th month). Fifteen (15) 6 years old eucalyptus trees were selected (5 trees/treatment), cut and wood samples at DBH (1,3 m) were taken for anatomical characteristics (fiber and vessels) and wood density analysis. Results showed that eucalyptus trees treated with mineral fertilizers did not show significant alteration in average wood density, with radial profile model common to all three treatments, characterized by a values increase in the region next to the pith, toward to bark. Mineral fertilization influenced wood anatomical characteristics: treatment with sodium was characterized by thinner walls and lumen larger diameter; in treatment with potassium, larger vessels were detected.

RESUMO A produção de painéis envolve parâmetros de processamento que interferem nas propriedades e na umidade de equilíbrio dos painéis. Dentre os parâmetros do processamento, podemos citar a massa específica dos painéis, razão de compactação, tipo e conteúdo de adesivo, conteúdo de parafina, dimensão e umidade das partículas, tempo de fechamento da prensa, temperatura e tempo de prensagem e pressão específica. Todos esses parâmetros podem ser controlados, visando a melhorar as qualidades do painel. Este trabalho teve como objetivo estudar a influência das variáveis de processamento (teor de resina, temperatura de prensagem e tempo de prensagem) nas propriedades físicas dos painéis. No Laboratório de Tecnologia e Produtos Florestais da Universidade Federal do Paraná, foram produzidos 27 painéis homogêneos de camada única sem orientação com partículas strand, com as dimensões de 480 x 480 x 15 mm; e no Laboratório de Tecnologia da Madeira da Universidade Federal de Lavras, foram gerados os corpos-de-prova para estudo das propriedades físicas (inchamento em espessura, absorção de água e taxa de não-retorno - TNRE) dos painéis. Os resultados demonstraram que o teor de resina, a temperatura e o tempo de prensagem afetam, de forma significativa, a retenção de água pelos painéis.

ABSTRACT The production of panels encompasses processing parameters that interfere in the properties and in the equilibrium moisture content of the panels such as specific gravities, compaction ratio, type and amount of adhesive, paraffin content, dimension and moisture content of the particles, time of closing the press, temperature and time of pressing and specific pressure. All these parameters can be controlled aiming to improve the quality of the panels. The study determined the influence of some processing variables (resin content, temperature and time of pressing) in the physical properties of the panels. At the Wood Technology and Forestry Products Laboratory of Universidade Federal do Paraná, 27 homogeneous single layer measuring 480 x 480 x 15 mm were produced with strands without orientation and, at the Wood Technology and Forestry Products Laboratory of Universidade Federal Lavras, samples for the physical properties testing (thickness swelling, water absorption and the nonrecoverable tax - TNRE) were generated. Results demonstrated that the resin content, temperature and time of pressing affect drastically the retention of water by the panels.