Abstract

SANQUETTA, Carlos R. et al. Produção de Madeira Roliça para Serraria de Pinus taeda no Sul do Brasil: Abordagem Experimental. Silva Lus. [online]. 2001, vol.9, n.2, pp.161-169. ISSN 0870-6352.

This paper evaluates the effects of initial plant spacing on the round-wood yield for saw timber in loblolly pine plantations in Southern Brazil. Five initial densities were compared: (1) 2.5 m x 1.2 m; (2) 2.5 m x 2.0 m; (3) 2.5 m x 2.8 m; (4) 2.5 m x 3.6 m; and (5) 2.5 m x 4.4 m. Data came from a randomized blocks experiment established in a Brazilian forestry company. The experiment was analyzed through ANOVA and Tukey's test. Graphical analysis was also performed to evaluate the impact of five thinning regimes: (1): a single final cut at age 15 without thinning; (2) a single final cut age 20 without thinning; (3) systematic thinning at age 9 and final cut at age 20; (4) selective thinning at ages 9 and 15 and final cut at age 20; and (5) systematic cut combined with selective thinning at age 9, selective thinning at age 15 and final cut at age 20. The results revealed differences (p<0.01) among plant densities. Saw timber yield gradually increased with decreasing plant density, but remarkable differences were noticed for the two extreme treatments. The densities 2.5 m x 4.4 m and 2.5 m x 3.6 m, non-significantly different one another, were those of better performance. Simulation analysis, however, indicated that density effect may be minimized for a longer period of time, mainly because of the effect of thinning regimes.

Keywords : thinning; spacing; forest management; simulation; site.

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