Crescimento e potencial energético de plantas intactas e de brotações de plantas jovens de clones de eucalipto

• Autor(a) principal: Souza, Felippe Coelho de
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/3065
• topic: Talhadia; Decepa; Biomassa para energia; Eucalipto; Coppice; Hew; Biomass production for energy; Eucalypt; CNPQ::CIENCIAS AGRARIAS::RECURSOS FLORESTAIS E ENGENHARIA FLORESTAL::SILVICULTURA

The biomass of fast growth planted forests can be an option to meet the high demand of alternative energy source. This study aimed to analyze the growth and the energy potential of intact plants and coppice with or without sprout thinning, of eight eucalypt clones harvested in juvenile stage, in a 3x3m initial spacing, aimed at biomass production for energy in short rotations. This study was conducted in the municipality of Vazante, MG (17° 36'09"S and 46°42'02"W), in the cerrado region, with very strong water deficit during six months of the year. The decapitation was performed on 13 months old plants and the growth in diameter, height and volume of intact plants and coppice was evaluated until 55 months after planting. At 55 months after planting, wood samples were collected in order to determine its calorific value and the density for intact plants and coppice of the six most productive clones. The highest growth estimates in volume per hectare of the sprouts were displayed by the clones 58, GG100, 1000 and 36. There was no difference (p> 0.05) for the asymptotic values and growth trends in volume per hectare between the two levels of sprout thinning of most of the clones. Clones 8B and 1270 presented very low productivity and are not recommended for planting in the studied region. Comparing the growth of the sprouts and intact plants at 36 months of age, the estimates of volume per hectare of the sprouts were 67% higher than for the intact plants for the clone 58, 61% for the clone GG100, 252% for the clone 1000, 179% for the clone 36, 54% for the clone 26 and 93% for the clone 910, indicating the possibility of anticipating the rotation age for the coppice. The frequency of spouts per hectare at 55 months after planting was higher in the smallest diameter classes, which does not interfere in biomass production due to the greater number of stems per plant compared with the single stem of intact plants. The dry-weight biomass yield and the potential energy of the clone 1000 were smaller (p≤0.05) for the coppice with sprout thinning as compared to intact plants and coppice without sprout thinning, while the potential energy of the clone 36 was smaller for the coppice without sprout thinning. There were no differences (p>0.05) among the treatments for the other clones, for these variables. These results indicate that eucalypt harvesting in the juvenile stage and coppice management in short rotations can be used to produce biomass for energy in successive rotations, not being necessary to perform the sprout thinning for the studied clones. A better understanding of coppice growth and energy potential of different eucalypt genetic material is required as the plantations are managed in several rotations for biomass production for energy.