Forma do fuste e qualidade da madeira de eucalipto em diferentes espaçamentos e níveis de desbaste

• Autor(a) principal: Barros, Sandro da Silva
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/11145
• topic: Taper; Form factor; Heartwood/sapwood ratio; Basic density; Fator de forma; Relação cerne/alburno; Densidade básica; Manejo florestal; Desbaste Florestal; Biometria; Afilamento; Recursos Florestais e Engenharia Florestal; 630

The objective of the study was to verify the effects of spacing and thinning on the stem form and on the quality of the wood of a clone of Eucalyptus urophylla x Eucalyptus grandis. The study area has approximately 1.26 ha and is located in a rural property in the municipality of Sooretama, ES. The planting was carried out in May 2013, under a randomized complete block design with three replications, being evaluated six treatments: planting spacings of 3x3 m (T1), 3x2 m (T2), 2x2m (T3) without application of slabs; and 2x2m spacing with removal of 20% (T4), 40% (T5) and 60% (T6) of the basal area by the selective method. The thinning were made at 40 months. It was carried out at 61 months the harvesting of trees for the collection of the discs for analysis of the basic density and heartwood/sapwood ratio and made scaling to calculate the normal form factor and for the fit of the taper models. An identity test was performed to verify the equality between the treatments and, consequently, between the stems profiles. Five trees with a mean diameter per treatment were randomly selected and 5 cm thick discs were collected at the DBH and at the following positions: 0, 25, 50, 75 and 100% of the commercial height of the trees (Hc). Form factors were found varying between 0.46 and 0.50, where greater spacing and weights of thinning resulted in a smaller form factor. There was a significant difference between the equations fitted for the spacings (T1, T2 and T3) and between the equations for the 3x2m spacing without thinning (T3) and the thinning of 20% (T4). Among the equations of the weight of thinning of 40 (T5) and 60% (T6) there was no significant difference, which indicates that the same taper equation can be used to model the tree stem profile of these treatments. The average heartwood/sapwood ratio found was 0.32 and the basic density was 0.55 g.cm-3, with no difference between the spacing and thinning levels analyzed.