EFEITO DO ESPAÇAMENTO NA PRODUÇÃO, VARIÁVEIS DENDROMÉTRICAS E PROPRIEDADES DA MADEIRA DE Eucalyptus benthamii

Abstract

Whereas the spacing is one of the determining factors for forestry production and considering that can cause changes in the growth rates of the forest and on the wood properties, the present study aimed to evaluated the effect of four planting spacing in the production and development of dendrometric Eucalyptus benthamii variables and the physical and mechanical properties of the wood. Evaluations were performed at six years of age, with dendrometric data and wood samples obtained from an experimental planting deployed to the 2006, in Guarapuava - PR. The planting was conducted in randomized block design on four spacings: 3 x 2m, 3 x 3m, 4 x 3m and 4 x 4m. The dendrometric variables DBH(cm), total height(m), cross section area (m?) , basal area (m? .ha?¹), individual volume (m³) and volume .ha?¹ ha (m³. ha- 1) were evaluated according of different planting spacing. The correlation between these variables and the vital space were also evaluated. The physical properties of wood, the variation of average basic density and dimensional stability of wood were evaluated against the planting spacing and sampling position on the stem wood. The basic density weighted by the volume and properties of strength and stiffness of the timber were determined by mechanical testing, were characterized and analyzed only under the effect of spacing. In general, the dendrometric variables were highly correlated with the spacing. The wider spacings favored the diameter, height, cross-section area and individual volume, while smaller vital spaces were responsible for the higher values of basal area and volume per hectare. Production ranged from 238.90 m³. ha- 1 in the greater spacing and 392.08 m³. ha?¹ in smaller spacing. Basic density was not influenced by spacing, and the average recorded between the four spacings was 0.49 g/cm³. The values of wood shrinkage demonstrated high dimensional instability. Few effects of spacing were recorded on the mechanical properties of the wood, and in age evaluated the wood can be characterized with low to medium strength. In this study it was concluded that different planting spacings influenced the growth of dendrometric variables and forestry production, however, were not responsible for changing the physical and mechanical properties of wood.