The anatomical structure and physical properties of wood change signifcantly among trees of the same species and even among different parts of the same tree. However, studies that characterize radial variation of anatomical characteristics and wood density among clones are scarce, specifcally for the rubber tree [Hevea brasiliensis (Will. ex Adr. De Juss.) Muell]. Thus, the objective of the research was evaluating the anatomical radial variation and density in wood of Hevea brasiliensis clones. For this study, 30 trees, three of each progeny from 10 clones were used. For most clones, we noticed an increase in fber length and vessel diameter towards the bark. For vessel frequency, ray height, width and frequency, we observed a decrease towards the bark. Fiber wall thickness was the most distinctive anatomical characteristic, compared to the others, presenting a trend of thicker walls in the middle position, consequently infuencing basic density clones.

Based on the use of Hevea brasiliensis in latex production, the species has a consolidated role in the Brazilian economy. However, at the end of the production cycle, which lasts from 25 to 30 years, resulting wood, in general, has no added value and is normally used for firewood, without further exploring its technological properties. Seeking to introduce this species into the pulp and paper industry, we aimed to determine the fiber quality of 20 commercial clones. Wood samples were collected from planted trees (11 to 12 years old) in the municipality of Selvíria - MS. We calculated wood quality indexes of H. brasiliensis for cellulose and paper, including Flexibility coefficient, Wall proportion, Runkel ratio, Slenderness ratio (Aspect ratio), and Luce's Shape Factor. The fiber quality indexes that best indicate the potential use of wood from Hevea brasiliensis clones for cellulose and paper production were Wall Fraction, Runkel Ratio and Luce's Shape Factor, indicating that H. brasiliensis fibers, if used for proper industrial purposes, will give origin of a rigid paper with greater bonding contact on the surface. The clones that presented better results for fiber quality indexes were IAC 311, IAC 41, IAN 873, IAC 326, IAC 40 and RRIM 725. Enabling the use of wood after the latex exploratory cycle for pulp and paper will serve as a basis for genetic improvement of these clones and expansion of forest plantations for this purpose.

Este trabalho tem por objetivo analisar a homogeneidade das amostras de solo das árvores nativas plantadas há 20 anos na Floresta Estadual de Batatais em comparação com outros usos/ocupação. Ao longo da projeção da copa de oito espécies nativas foram coletadas amostras compostas de solo na profundidade 0-0,20 m, que foram avaliadas junto com o solo de outros estudos com árvores de progênies de Eucalyptus pellita, de E. tereticornis e do plantio comercial de Pinus caribaea hondurensis e P. c. bahamensis. A análise multivariada dos atributos do solo das espécies nativas restou não significativa, indicando a homogeneidade do solo na área de estudo, restando a expressão genética das espécies para outras variáveis dendrométricas e de qualidade da madeira a serem estudadas. Por outro lado, a análise multivariada das espécies nativas com as de Eucalyptus e Pinus resultaram altamente significativas, mostrando que existe diferença dos atributos do solo em relação aos diferentes usos/ocupações. Os Eucalyptus apresentam maior teor de bases que o Pinus e o Florestamento, em áreas com menor acidez potencial e maior capacidade de troca de cátions (CTC), restando à área com Florestamento maior acidez potencial e menor CTC.