干旱区生态环境知识资源中心

Energy production is one the most important topics worldwide. Native forests are good contributors for the production of bioenergy. However, in environmentally difficult conditions, such as arid and semi-arid lands, native trees species produce low woody volume. Alternatives of raw sources from forest plantations of fast growing species, such as eucalyptus, should be analyzed. Firewood production and physical properties of Eucalyptus camaldulensis and E. microtheca on semi-arid land were determined. Yield and quality of charcoal produced at 450, 650, 850, and 1050 degrees C from sapwood and hardwood under laboratory conditions were analyzed. Data were analyzed as random blokes, and ANOVA tests were developed to determine differences in charcoal yield and quality between temperatures and anatomical sections on both species. Eucalyptus microtheca produced higher firewood volume (71.10 m(3) ha(-1)) than E. camaldulensis (19.78 m(3) ha(-1)). Green (1.0 to 1.3 g cm(-3)), oven-dry (0.8 to 1.1 g cm(-3)), and basic densities (0.6 to 0.9 g cm(-3)) showed statistical differences between species and wood type. Statistical differences (p < 0.0001) in the charcoal yield of both species were found; E. microtheca heartwood produced the highest charcoal yield (44%) at a temperature of 450 degrees C. Correlation coefficient between basic density and charcoal yield at all temperatures was high (r = 0.36 to 0.72). Values of moisture content, ash, volatile materials, fixed carbon, and calorific value meet the international standard requirements.