ABSTRACT
This study had the objective of simulating and evaluating economically thinning regimes and pruning for Pinus taeda, to obtain clearwood and wood for multiple uses. The area of study, is located in the county of Jaguariaiva, State of Paraná - Brazil. Two scenarios were tested with different numbers, time and thinning intensities from different initial planting densities, at different levels of productivity, aiming at the production of pruning wood, clearwood and no pruned wood for several uses. The generated management regimes were submitted, during the investment analysis, to 3 discount rates and for 6 different options of pruned wood prices related to no pruned wood, totaling 86,022 different management options. The growth, yield and thinning simulations were made by the PISAPRO software. The economic analyses were performed through the maximization of the present net value by using the INVEST software. The management regimes, which presented highest profitability for class I and II sites and for the stipulated prices, were those with 833 trees per hectare initially, and with final felling at 21 years after 3 thinning operations: a pre-commercial thinning followed by pruning at the age of 4 maintaining 500 trees/ha, a commercial thinning at the age of 12 maintaining 400 trees/ha and a third thinning (commercial) at the age of 14 maintaining 100 trees/ha. For the site III, the best option was the adoption of management the age of regimes with 1111 planted trees/ha and final cutting at 20 years, after the accomplishment of a pre-commercial thinning followed by pruning at the age of 4 maintaining 500 trees/ha and a commercial thinning at the age of 12 maintaining 200 trees/ha. The second pruning for the 3 classes for the site III was achieved between 7 and 8 years of age.
Key words:
simulation; thinning; pruning; investment analysis