Estoque de biomassa e carbono em cerrado e em plantio comercial de eucalipto no Estado de Minas Gerais

• Autor(a) principal: Ribeiro, Sabina Cerruto
• Data de Publicação: 2011
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/565
• topic: Plantação florestal; Cerrado; Equações alométricas; Plantation forestry; Cerrado; Allometric equations; CNPQ::CIENCIAS AGRARIAS::RECURSOS FLORESTAIS E ENGENHARIA FLORESTAL::MANEJO FLORESTAL

In Brazil plantations occupy about 6,510,693 hectares and usually form a mosaic with native forests. Therefore biomass and carbon stock studies should consider both vegetation forms. This study aimed the quantification of biomass and carbon stock of a commercial Eucalyptus planting and a cerrado sensu stricto (cerrado s.s.) remnant embedded in an Eucalyptus matrix. The biomass and carbon stock quantification in both vegetation forms took place in Curvelo, in the state of Minas Gerais, in a privately owned forestry company that operates in pig-iron production. In the cerrado s.s. remnant, 120 trees from 18 species were destructively sampled for biomass and carbon content determination of the stem, branches and leaves. Five models with DBH, height (H), DBH2H and wood basic density as independent variables were tested for the estimation of individual tree aboveground biomass. One model based on basal area as a stand parameter was also tested as an alternative approach for predicting aboveground biomass in the stand level. Belowground biomass and roots‟ carbon content was estimated by subsampling on 10 sample plots. For the Eucalyptus, 23 sample trees were harvested for aboveground biomass assessment. Nine of the 23 sampled trees were selected to assess the roots biomass. Beside of the biomass quantification of the stem, branches, leaves and roots, the carbon content of these compartments were determined in laboratory. Two models were tested to estimate the total amount of carbon and total biomass using DBH, H and DBH2H as independent variables. An estimate of carbon stock in the stand level was also generated. In the cerrado s.s. remnant we verified that the mean aboveground tree biomass (bole, branches and leaves) and mean belowground biomass accounted for 62.97 t ha-1 and 37.50 t ha-1, respectively. Our estimates of aboveground biomass are higher than reported by other studies developed in the same physiognomy, but the estimates of belowground biomass are within the range of values reported in other studies. The best-fit equation for the estimation of individual tree aboveground biomass include DBH and wood density as explanatory variables ( 2 = 0.896; SEE = 0.371). In the stand level, the model tested presented a good fit ( 2 = 0.926; SEE = 0.224). The mean carbon content of bole + branches, leaves, roots, shrubs and litter is 48%. The total estimated carbon stock for the cerrado s.s. remnant is 54.36 tC ha-1. For the Eucalyptus plantation, we found an average carbon content for the stem, branches, leaves and roots of 44.6%, 43.0%, 46.1% and 37.8%, respectively. The carbon content of stem, branches, leaves and roots was smaller than the generic value commonly used (50%). This highlights the importance of determining the carbon content in laboratory instead of using a default value. Total stand carbon stock in the Eucalyptus plantation was estimated to be 73.38 tC ha-1, being within the carbon stock range for Eucalyptus plantations. The best-fit allometric equations to estimate the total amount of carbon and total biomass had DBH2H as independent variable.