Estrutura de copa, crescimento e valor econômico de um povoamento de eucalipto submetido a desrama e desbaste

• Autor(a) principal: Ramos, Diêgo Correa
• 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/123456789/3085
• topic: Desrama artificial; Desbaste; Multiprodutos; Artificial pruning; Thinning; Multiproduct; CNPQ::CIENCIAS AGRARIAS::RECURSOS FLORESTAIS E ENGENHARIA FLORESTAL::SILVICULTURA

Canopy structure, growth and economic value were evaluated in a pruned and thinned Eucalyptus grandis W. Hill ex Maiden clone stand, in Abaeté, Minas Gerais (19º 15 94 S e 45º 44 56 W ). The thinning treatments included the removal of trees in the following ages and weights: 0% (SD), 35% of total planted trees at 55 months (35% 55) and 81 months (35% 81), and 70% at 81 months, with coppice removal (70% 81 SB) and without coppice removal (70% 81 CB) from thinned trees. The canopy cover index (CCI) was obtained at the age of 141 months by taking digital photographs (3216x2116 pixels), which were processed through the software SIDELOOK 1.1. The leaf area index (LAI) was obtained with the LI-COR canopy analyzer. The diameter (DBH) and height (Ht) of the trees were measured from the age of 81 to 141 months. The multiproduct economic viability was evaluated at the age of 141 months. LAI varied significantly (p ≤ 0.05) with thinning treatments up to 141 months. The treatments 35% 81, 70% 81 CB and no thinning presented LAI 20% higher than for the 70% CB 81 treatment. There was a 25% LAI reduction at 141 months as compared to 102 months, indicating a possible site quality decline. All thinning treatments presented different (p ≤ 0.05) CCI s. At 141 months, there were differences (p ≤ 0.05) in DBH, Ht, volume outside bark (Vcc), periodic annual increment after thinning (PAI) and mean annual increment (MAI) among thinning treatments. The total height was lower (p ≤ 0.05) for the treatment 70% 81 CB. The number of individuals was greater in larger diameter classes for the 70% 81 SB followed by the 35% 55, 35% 81, 70% 81 CB and SD. By maintaining one sprout per stump in the thinned trees there was growth reduction of the remaining trees. The PAI was higher (p ≤ 0.05) for the 35% 55 and the Vcc was higher (p ≤ 0.05) for the SD treatment. The 70% 81 SB and 35% 55 thinning treatments attained economic return higher than for the other treatments due to large production of clearwood. All management regimes studied presented economic viability for a discount rate of 8% a.a.