The growth of intact plants and coppice of juvenile plants of eight eucalypt clones (3 9 3 m spacing) was evaluated in the savanna region, Brazil (17°36 0 09 00 S and 46°42 0 02 00 W), aiming for biomass production for energy in short rotations. The treatments included intact plants and juvenile plant coppice (cut at 13 months of age). Coppice was managed either with thinning to two sprouts/stump at 9 months after harvesting or without sprout thinning. The diameter of the intact plants was greater than that of coppice for clones 58, GG100, 26 and 8B, and no differences were noted between treatments for the other clones. Yield did not differ between the thinned and unthinned sprouts for most clones. At younger ages, the coppice yield was greater than that of the intact plants for most clones. Later, there was a decline in the coppice yield, and intact plants surpassed coppice. Then, the maximum coppice mean annual increment was achieved at younger ages than for the intact plants, which resulted in coppice rotation age shortening. The greatest differences between the coppice and intact plants yield was between 38 and 40 months, when the coppice yield was 59, 56, 127, 149 and 75 % greater than that of the intact plants, for the clones 58, GG100, 1000, 36 and 910, respectively. Clone GG100 revealed the highest yield estimation among the intact and coppice plants. The results indicate that by coppicing juvenile eucalypt clone plants, in dense stands, it is possible to produce biomass for energy, without sprout thinning, if rotation age is shortened.
O objetivo foi analisar a capacidade de manutenção da umidade do solo sob diferentes coberturas vegetais (eucalipto, mata nativa e pastagem) em estágio maduro de desenvolvimento em uma bacia hidrográfica na Zona da Mata de Minas Gerais. Três amostras compostas deformadas de solo por parcela foram coletadas nas profundidades de 0-10 e 10-20 cm para análise da matéria orgânica e das propriedades físicas dos solos (textura, porosidade total, densidade de solo e densidade de partículas). A umidade foi monitorada através de amostras de solo, nas profundidades avaliadas, a cada sete dias, durante cinco semanas. O solo sob plantio de eucalipto apresentou os menores valores de densidade de solo e de partículas, em comparação aos solos sob pastagem e mata nativa. A mata nativa apresentou maior contribuição na formação de matéria orgânica do solo (MOS). O eucalipto foi a cobertura vegetal que melhor reteve umidade do solo, seguido da mata nativa e pastagem (eucalipto > mata nativa > pastagem). O manejo inadequado da pastagem afeta negativamente o conteúdo de matéria orgânica e a capacidade de manutenção da umidade no solo. Plantios de eucalipto, quando bem manejados, favorecem o incremento de matéria orgânica no solo, aumentando a capacidade de retenção de água.
-A pruned stand of eucalypt clone underwent five thinning treatments with the removal of different proportion of the planted trees, at different ages: a) 0% -unthinned, b) 35% at 55 months, c) 35% at 81 months, d) 70% at 81 months, removing sprouts in the thinned plant stumps and, e) 70% at 81 months, without coppice sprouts removal. By the age of 141 months, the Weibull distribution showed higher number of trees in the smallest diameter classes for the unthinned treatment. The 70% thinning, with thinned coppice sprouts removal, presented higher number of individuals in the largest diameter classes. Height and yield were the smallest with the removal of 70% of the trees at 81 months, maintaining coppice sprouts. The afterthinning periodic annual increment was greater by thinning 35% of the trees at 55 months resulting in greater number of trees in the largest diameter classes as compared to the other treatments. Yield was higher for the unthinned treatment. The results of this study indicated that thinning 70% of the trees at the age of 81 months, with coppice sprout removal, could be recommended to obtain trees of larger diameter for multiproduct.Keywords: Forest yield; Diameter distribution; Eucalypt clone. EFEITO DO DESBASTE SOBRE O CRESCIMENTO DE PLANTAS DE CLONE DE EUCALIPTO DESRAMADO RESUMO -Um povoamento desramado de eucalipto foi submetido a cinco tratamentos de desbaste, com remoção de diferentes proporções das árvores plantadas e idades: a) 0% não desbastado, b) 35% aos 55 meses, c) 35% aos 81 meses, d) 70% aos 81 meses, removendo a brotação nas cepas desbastadas e e)
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.