Marcos Felipe Nicoletti

Metodologia alternativa para o Teste de Tetrazólio em sementes de Araucaria angustifolia (Bertol.) Kuntze

The objective of this research was to verify the possible use of an alternative methodology for the tetrazolium test in A. angustifolia seeds. Seeds of three lots were submitted to immersion in water for 18 hours. The seeds had their coats and nutritive tissue removed and the embryos were soaked in 1.0%, 0.5% and 0.1% tetrazolium solution at 25 °C for one hour, applying the standard methodology described for the species. Germination tests were performed to verify the reliability of results through the tetrazolium test. Immersion in water for 18 hours followed by the removal of seed coat and nutritive tissue and immersion in tetrazolium solution at 0.1% or 0.5% at 25 °C for 1 hour was an efficient methodology to evaluate the seed viability of A. angustifolia.

Metodologia Alternativa para o Teste de Tetrazólio em Sementes de Araucaria angustifolia (Bertol.) Kuntze / Alternative Methodology for the Tetrazolium Test in Araucaria angustifolia (Bertol.) Kuntze Seeds

The objective of this research was to verify the possible use of an alternative methodology for the tetrazolium test in A. angustifolia seeds. Seeds of three lots were submitted to immersion in water for 18 hours. The seeds had their coats and nutritive tissue removed and the embryos were soaked in 1.0%, 0.5% and 0.1% tetrazolium solution at 25 °C for one hour, applying the standard methodology described for the species. Germination tests were performed to verify the reliability of results through the tetrazolium test. Immersion in water for 18 hours followed by the removal of seed coat and nutritive tissue and immersion in tetrazolium solution at 0.1% or 0.5% at 25 °C for 1 hour was an efficient methodology to evaluate the seed viability of A. angustifolia.

Avaliação das Principais Propriedades Físicas e Mecânicas da Madeira de Eucalyptus benthamii Maiden et Cambage

The present study aimed to assess the physical and mechanical properties of Eucalyptus benthamii Maiden et Cambage wood. The following physical properties were determined: apparent density at 12 and 0% moisture content, basic density, and indices of contraction. Mechanical properties were determined through tests of static bending, compression parallel to the grain, shear, and hardness in six-year-old wood. Based on the results obtained in the determination of physical properties, E. benthamii wood at the age studied can be classified as moderately heavy and dimensionally unstable. The species showed low resistance with respect to mechanical properties, which can be related to the large amount of juvenile wood observed in the material studied.

Avaliação das Principais Propriedades Físicas e Mecânicas da Madeira de Eucalyptus benthamii Maiden et Cambage / Evaluation of the Main Physical and Mechanical Properties of Eucalyptus benthamii Maiden et Cambage Wood

The present study aimed to assess the physical and mechanical properties of Eucalyptus benthamii Maiden et Cambage wood. The following physical properties were determined: apparent density at 12 and 0% moisture content, basic density, and indices of contraction. Mechanical properties were determined through tests of static bending, compression parallel to the grain, shear, and hardness in six-year-old wood. Based on the results obtained in the determination of physical properties, E. benthamii wood at the age studied can be classified as moderately heavy and dimensionally unstable. The species showed low resistance with respect to mechanical properties, which can be related to the large amount of juvenile wood observed in the material studied.

Exatidão de dendrômetros ópticos para determinação do volume de árvores em pé

The aim of this paper is to verify the accuracy of the optical dendrometers Criterion 400 and RC3H by studying the quality of measures of wood volume determination of standing trees through these dendrometers. The study was developed at the Experimental Station of Forest Sciences, in Itatinga, Sao Paulo state, which belongs to the University of Sao Paulo (ESALQ / USP). It was sampled a total of 175 trees in three plots of Eucalyptus grandis. The stem diameter of standing trees was measured by the two optical dendrometers at distances of 0.1, 0.4, 0.7, 1.0, 1.3, 2.0 meters from this point meter by meter along the stem up to 8 meters height. After measuring the standing trees they were felled and the diameter was obtained in different positions with a caliper and a tape in the same positions that the non-destructive measures were taken. With the diameters the volume was calculated by section and by individual trees by the Smalian formula for the comparison of methods. Analyzing the measurements of stem diameter and the individual tree volume realizes that the two dendrometers provided measures generally underestimated. However, the Criterion provided the best estimates. For the diameter and individual tree volume the Criterion showed underestimated errors averaging approximately 1 cm (10%), while the RC3H resulted in errors greater than 5 cm (30%) on average.Thus, when measuring observed variables in a non-destructive way with reliability and accuracy, the Criterion showed better results.

Relação Hipsométrica para Pinus taeda L. em Diferentes Fases do Ciclo de Corte

This study aimed to evaluate the different phases of the cutting cycle, seeking a proper hypsometric rate to estimate the height of these different phases in a reforestation of Pinus taeda. The study consisted of five treatments, being the fifth the combination of the data belonging to the other treatments. The sampling followed the fixed area method where plots size and number of dominant trees varied with each cutting cycle. The plots location was defined by simple random sampling (eight portions by cutting cycle). We determined the statistical adjustments, adjusted coefficient of determination, standard error and residual analysis. We performed the Graybill identity test to assess the need to use different models for different age classes. Results showed that there are significant differences between adopting a specific model to each stage and use a single best model for the full settlement.