Custo, tempo e precisão: uma otimização do inventário florestal pré-corte em um povoamento de eucalipto

Abstract

Forest inventory is a key practice for quantifying and qualifying the productive potential of a forest. Sampling intensity, size and shape of the sample plots are crucial for this activity, as they affect directly the costs and time of data collection and the accuracy. This study aimed to evaluate, in terms of precision, costs and time, the use of different sizes, shapes and arrangements of sample plots in a Eucalyptus spp. pre-harvest forest inventory. The research was conducted on a farm, northern of Minas Gerais State, Brazil. A forest census and volume of wood with rigorous cubing data were performed. For the analysis we considered two sampling processes (systematic and simple casual sampling), four plot sizes (200, 300, 400 and 500 m²) and two shapes (circular and rectangular). The sample intensity was set in 5 plots for all scenarios. Simulations (10,000) were carried out by the Monte Carlo method, in order to verify the probability of the values to be close to the mean. The combined analysis of error, costs and measurement time showed that for a 8-year-old stand of Eucalyptus spp., casual sampling with circular sample plots of 300 m² represents the optimal sampling scenario.