Número de alturas medidas e seus efeitos sobre os custos operacionais do inventário florestal

Abstract

Forestry inventory is a fundamental part of the process for obtaining stock and productive potential from a planted forest. Height measurement is one of the most time-consuming and, therefore, expensive steps of this process. The planning of height sampling for hypsometric relations adjustments must take into account besides the adequate precision of estimates, the reduction of inventory costs. Therefore, this study aimed at test technical variability reduction of 50% in the number or measured trees in the inventory data from a company in the North of Minas Gerais State, and simulating the resulting operational costs reduction. Curtis Model was used for adjustments per plot according to the standard adopted by the company (measurement of 10 trees plus the trees with the dominant height) and for the adjustment with the reduction of 50% of the measured trees, plus the trees with the dominant height. Observed through statistics the of Adjusted Determination Coefficient (R2) and the Standard Error (Syx) showed that the reductions were acceptable for all tested plots. The simulations of costs reduction were carried out for na expectative of addition of one, two and three plots per day and per team. The results showed that reducing the number of height measurements can lead to a cost reduction of over 20% a month.