Marcela Gomes da Silva

Sobrevivência de espécies arbóreas plantadas em clareiras causadas pela colheita de madeira em uma floresta de terra firme no município de Paragominas na Amazônia brasileira

Analisou-se a sobrevivencia de mudas plantadas em 400 clareiras causadas por exploracao florestal de impacto reduzido, em floresta de terra firme na Amazonia Oriental. Foram plantadas 3.818 mudas de 17 especies, das quais apenas Schizolobium amazonicum nao ocorre na area de estudo. A distância entre as mudas plantadas foi de aproximadamente 5m. As avaliacoes ocorreram em 2005 e 2006. Com base na sobrevivencia das mudas aos 11 meses apos o plantio, as especies indicadas para o enriquecimento de clareiras sao: Schizolobium amazonicum, Cedrela odorata, Jacaranda copaia, Manilkara huberi, Astronium gracile, Pouteria bilocularis, Tabebuia impetiginosa,Pseudopiptadenia suaveolens, Cordia goeldiana, Parkia gigantocarpa, Simarouba amara, Sterculia pilosa, Laetia procera, Dinizia excelsa e Schefflera morototoni. Estudos sobre a taxa de crescimento, em periodos mais longos, sao necessarios para confirmar a utilizacao dessas especies em plantios de enriquecimento de clareiras oriundas de exploracao florestal, como alternativa para aumentar a produtividade e o valor economico das florestas naturais manejadas na Amazonia brasileira.

IMPORTANCE OF WOOD DRYING TO THE FOREST TRANSPORT AND PULP MILL SUPPLY

The forest transportation represents a great proportion of raw material cost for pulp and paper production and, for this reason, the wood moisture content should be low to reduce these cost. The objective was to relate the wood moisture with fuel consumption per kilometer in each vehicle and the number of trips to supply a pulp mill. Three trees of

Properties of osb panels with veneer inclusion

This work aimed to evaluate the effect of veneer inclusion with different wood species, and also different levels of pressing pressure applied in the moment of the veneer inclusion over physicalmechanical properties of already consolidated OSB (Oriented Strand Board) panels. Treatments were arranged in factorial scheme 4 x 2 (four wood types for veneer inclusion – Pinus oocarpa, Eucalyptus urophylla, Parkia gigantocarpa and Brosimum parinariodes; and two pressing pressures – 1 and 2 MPa) and also a control (without veneer inclusion). Veneer inclusion was made with 180 g.cm-2 phenol formaldehyde adhesive, in a simple glue line, perpendicular to the external layer of panels. The pressing cycle used was 150oC for 4 minutes under pressure 1 or 2 MPa pressure depending on the pre-established treatment. It was possible to conclude that: 1) Veneer inclusion with pines, eucalypt and amapa promoted significant improvements for physical-mechanical properties of OSB panels, highlighting eucalypt and amapa; 2) There was not a significant effect of the level of pressing pressure over mechanical properties of OSB with veneer inclusion; and 3) Regarding physical properties, the highest pressure level (2 MPa) promoted a negative effect in some properties, while veneer inclusion the pressure of 1 MPa generally promoted significant improvement of all physical properties.

Adesivos tânicos de Stryphnodendron adstringens (Mart.) Coville na produção de painéis aglomerados

The world seeking alternative sources for adhesives production by using renewable raw material. In this context, the use of Stryphnodendron adstringens (Mart.) Coville tannins bark have been showing potential. The aim of this study was to evaluate the technical feasibility of using tannic adhesive from the barks of barbatimao, for particleboard production. Tannin-based adhesives extracted from the bark of barbatimao were used in ratio of 0, 25, 50, 75 and 100% with commercial urea formaldehyde adhesive. Pure and mixtures adhesives had their properties determined. Particleboards with urea-formaldehyde, tannin-formaldehyde and its mixtures were produced and had their physic-mechanical properties tested. The adhesive tannic of barbatimao proved be technically feasible in the proportion until 50% for particleboard panels type, however, it is recommended to indoors use only, without moisture contact.

Prediction of the physical, mechanical and colorimetric properties of Eucalyptus grandis heat-treated wood using artificial neural networks

Heat treatment is important to change wood color and increase its dimensional stability, though the quality control and modeling during this process need to be further studied. The aim of this study was to evaluate the efficiency of artificial neural network based in temperature to predict the Eucalyptus grandis wood properties after heat treatment. The physical, mechanical and colorimetric properties of the wood samples after heat treatment at 140, 170, 200 and 230°C for three hours under atmospheric pressure and the presence of air were evaluated. An artificial neural network based on the heat treatment temperature was established to predict the equilibrium moisture content, total volumetric swelling, modulus of rupture, modulus of elasticity, lightness (L*), green-red coordinate (a*) and blue-yellow coordinate (b*) of the wood. The equilibrium moisture content, total volumetric swelling and modulus of rupture (MOR) were affected from 170°C, the modulus of elasticity from 200°C, the oven-dry density from 230°C and colorimetric parameters from 140°C onward. The artificial neural network estimated results with precision, showing its potential for quality control in the wood heat treatment process.

Effect of the post-harvesting silviculture on a Lecythis Lurida (Miers) Mori population in a 'terra firme' forest in Brazil's Amazon forest

The growth rate of trees dbh > 35cm of a Lecythis lurida (Miers) Mori (jarana) population was evaluated in a 700ha area of natural forest after logging and applying silvicultural treatments in the municipality of Paragominas, in Para state. Seven treatments were established: in three of them climbers were cut and competitor trees were girdled after logging; in two of them only climber cutting was performed; in one 1 Engenheira Florestal, Mestre em Ciencias Florestais, Universidade Federal Rural da Amazonia, Rua Duque de Caxias, 71, Matinha, CEP 68030-000, Santarem (PA), Brasil. sol_taffarel@yahoo.com.br 2 Engenheiro Florestal, Dr., Professor Visitante Nacional Senior (CAPES/UFRA Universidade Federal Rural da Amazonia), Estrada do Quarenta Horas, Villa Firenze 0718, CEP 67120-370, Ananindeua (PA), Brasil. Bolsista do CNPq. olegario@pq.cnpq.br 3 Engenheira Florestal, Dra., Professora da Universidade Federal do Oeste do Para. Rua Vera Paz, s/n, Bairro Sale, CEP 68035-010, Santarem (PA), Brasil. lcolivei@gmail.com 4 Engenheira Florestal, Msc., Doutoranda do Programa de Pos-Graduacao em Ciencia e Tecnologia da Madeira, Universidade Federal de Lavras, Caixa Postal 3037, CEP 37200-000, Lavras (MG), Brasil. marcela.gsilva@gmail.com 5 Engenheira Florestal, Msc., Doutoranda do Programa de Pos-Graduacao em Ciencias Florestais, Universidade Federal Rural da Amazonia, Cidade Nova III, Travessa SN 13, Casa 01, CEP 67130-400, Ananindeua (PA), Brasil. jaquelinemacedogomes@hotmail.com 6 Engenheiro Florestal, Empresa Cikel Brasil Verde Madeiras, Estrada do Quarenta horas, Villa Firenze 1305, CEP 67120-370, Ananindeua (PA), Brasil. evandro@cikel.com.br Recebido para publicacao em 31/03/2011 e aceito em 23/04/2013