Modelagem e avaliação econômica de plantações de eucalipto submetidas a desbastes / Modeling and economic evaluation of plantations of eucalypts submitted to thinnings

AUTOR(ES)
DATA DE PUBLICAÇÃO

2000

RESUMO

The objective of the present work was to evaluate the efficiency of the Clutter model (1963) to predict the growth and yield of thinned stands of eucalypts and to economically evaluate various thinning intensities. The study was developed with data of an essay about thinnings established in stands of eucalyptus belonging to the Copener Florestal Ltda., located in the Northern Region of the Bahia State, Brazil. The essay was composed by four treatment, which correspond to different percentages of removed basal area, designed in randomized blocks, with two repetitions per block, located in a selected way in three places with different productive capacities, at a total of 48 plots, with a mean area of 2,600 m2 each. The mensurations were made at the age of 27, 40, 50, 61, and 76 months, and on the fourth mensuration, at 58 months, the thinning was done. In each mensuration, the height and diameter of the crown, the total height of almost all trees, and the DBH of all of the trees of the plots were recorder. First of all, the local productive capacities were checked, using the lead-curve method, which is considered to be more efficient than the methods of correlated curves and of prediction of parameters. To obtain the production per area, the Clutter model (1963) was used. Production tables with variable densities were made, with simulations of thinnings, from which the thinned and harvested volumes at the final cut were determined for the various intensities. For the analysis of the technical and economic aspects of the various intensities of thinnings, each one was considered as a single project, using data of outputs and incomes obtained with the intermediate harvest (thinnings) and with the final harvest in each case. For the economic evaluation the projects were compared, using the criteria of the equivalent periodic benefit (BPE). It was found that the differences on the intensities of remotions in based area did not influence the total volumetric production. Greater thinning intensities caused a delay of the final cutting age, or, of the technical rotation age, and, in terms of economy, this decreased benefits (BPE). This fact occurred, mainly, due to the price fixed for wood of find cut, which did not consider the qualitative changes occurring in the stand with the thinning. The Clutter model showed to be efficient for predictions in thinned eucalyptus stands.

ASSUNTO(S)

manejo florestal modeling desbaste thinnings eucalyptus eucalyptus modelagem

ACESSO AO ARTIGO

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