POTENCIAL ENERGÉTICO DE COMBUSTÍVEIS FLORESTAIS EM CULTIVOS DE Pinus elliottii NO SUL DO BRASIL

Abstract

In order to determine the potential energy of forest fuels in Pinus elliottii stands, we investigated the best season to collect fuel material considering fuel availability, moisture content, Higher Calorific Value (HCV) and immediate chemical composition, from the plots established and monitored during one year at Rio Negro Research station, Paraná state, Brazil. The year’s seasons (winter, summer, spring and autumn) were considered as experimental blocks while the diameter of the materials (AA, AB and AC) as treatments. These treatments were pre-defined in the following diameter classes: AA, in the upper layer; AB, in the intermediate layer; AC, in the lower layer, all materials up to 0,7 cm; and B, with material of 0.71 to 2.5 cm. The fuel material of all year’s seasons was collected in sub plots of 900 cm2, weighted in the field and taken to the laboratory of the Federal University of Paraná (UFPR) to carry out the rest of analyzes including: moisture on the dry basis, fuel availability, Higher Calorific Value (HCV) and immediate chemical composition. Analyses of variance (ANOVA) and Tukey test were performed to compare the differences between seasons and material classes. Together with low moisture content and greater fuel availability, the mean test showed that, for all material classes, the winter was the best season to collect forest fuel material of Pinus elliottii stands. The results also showed that, for immediate composition and HCV, the mean class AA and B were statistically superior than the other classes. The fuel loading had a considerable density of energetic (12,275.42.105 kcal. ha-1) for bioenergy conversion and utilization.