ENERGY PRODUCTION OF STEM OF Eucalyptus grandis Hill ex Maiden AND Acacia mangium Willd IN DIFFERENT LEVELS OF FERTILIZATION

Abstract

The objective of this work was to compare the energy production of Acacia mangium wood with Eucalyptus grandis at 7 yars old in Botucatu-SP. Both species belonged to a 2x2x2 fertilization trial with two randomized blocks in the presence and absence of calcium. A total of 128 trees from each tree specie was sampled with wood transversal sections collected along the height of each tree, in portions corresponding to the basis (0%), 25%, 50%, 75% of merchantable height and at top (100%). It was considered the diameter top of 4,0 cm outside bark as merchantable diameter. The wood basic density was determined by water displacement method and the dry mass without bark for each tree was estimated. The calorific power was determined and the heat quantities were estimated. Fertilization levels did not affected the parameters studied for both species. The average superior calorific power was 4,619 kcal/kg and 4,641 kcal/kg; the dry mass was of 19.76 kg/tree and 47.83 kg/tree and the energy quantities, in the heat form, produced were 91,285.62 kcal/tree, and 222,085.31 kcal/tree for Acacia mangium and for Eucalyptus grandis, respectively.