Environmental Effect on Chemical Composition of Eucalyptus Clones Wood for Pulp Production

Abstract

OLIVEIRA, J. T. S.; VIDAURRE, G. B.; RODRIGUES, B. P. Environmental effect on chemical composition of eucalyptus clones wood for pulp production. CERNE, v. 24, n. 3, p. 219-224, 2018. HIGHLIGHTSThe extractive content was the characteristic that suffered the highest site effect.The S/G ratio was considered to be the most stable characteristic to environmental change.There is a signifi cant variation between the values of S/G ratio among different clones.The holocellulose (%) was the second characteristic lowest infl uenced by the environment. ABSTRACTThis study aimed to evaluate the environmental effect on the wood chemical composition of Eucalyptus grandis x Eucalyptus urophylla clones for pulp production. Seven clones of 6.5 years old were evaluated. The clones were planted in two growing sites, Nova Almeida -Espírito Santo and Posto da Mata -Bahia, established in 3 x 3 m spacing. Five trees were selected from each clone and discs were removed from fi ve different positions equidistant from the trunk and at diameter at breast height (DBH) height. Two wedge from opposite sides were obtained from the discs. A chemical analysis was performed with a sample composed of all the wedges of each tree in order to determine extractive contents, lignin, holocellulose, carbohydrates and the ratio among syringyl (S) and guaiacyl (G) lignin substructures (S/G) per tree. The S/G ratio was considered to be the most stable characteristic to environmental change, followed by the holloceluloose content, which was considered the second least characteristic infl uenced by the growth site. Most of the studied clones presented a statistical difference between the growing site for the wood extractive content, in contrast to the total carbohydrates content that was highlighted by presenting values which were little infl uenced by the genetic material and the growth site.v.

Evaluation of Chemical and Morphological Properties of Spruce Wood Stored in the Natural Environment

“…After 2 months of storage, the content of extractives decreased by 14%. Bergström and Matison [47] and Freitas et al [28] describe a decrease in the proportion of extractives by approximately half during the first four weeks of wood storage. According to Holmbom [48], the largest decrease in the quantity of extractives is mainly related to the loss of hydrophilic The content of extractive compounds was 1.6% at the time of harvesting.…”

“…When producing wood pulp, it is important to use wood of certain quality, whereas the key point is the wood’s chemical composition, since there is a direct relation with the effectiveness of the pulping process [ 28 ]. For the needs of the pulp and paper production industries and for the production of wood pulp, it is necessary for the solution to penetrate completely into the wood chips.…”

Wood Quality and Pulping Process Efficiency of EliteEucalyptusspp. Clones Field-Grown under Seasonal Drought Stress

“…The Eucalyptus grandis x Eucalyptus urophylla hybrid has been widely used in Brazil, providing most of the raw material which is used for hardwood pulp companies [18]. Additionally, interspecific hybrids from species such as E. grandis, E. urophyla, Eucalyptus camaldulensis, Eucalyptus pellita and Eucalyptus tereticornis have been utilized as a strategy for dry environments [19].…”

Impacto da densidade básica da madeira de >i<Eucalyptus>/i< na eficiência dos processos de polpação kraft estendidos.

“…Dessa forma, a variação do teor de extrativos observada pode estar correlacionada a este conjunto de fatores, tendo em vista que as propriedades da madeira são resultantes da interação entre o potencial genético de dada espécie com as condições ambientais em que se desenvolve. A interação material genético e sítio de plantio foi demonstrada em estudos desenvolvidos por Gouvea et al (2012) e Freitas et al (2018), nos quais foram observadas influências do sítio de plantio no teor de extrativos em madeiras de Eucalyptus.…”

“…Muitos autores relatam correlações positivas entre a relação das unidades monoméricas da lignina siringila e guaiacila (S/G) com a facilidade de deslignificação da madeira e, por sua vez, Para as madeiras analisadas nesse estudo, foi observada correlação negativa entre a relação S/G e o rendimento depurado. Apesar de diversos autores citarem correlação positiva da relação siringila/guaiacila com a facilidade de deslignificação das madeiras, esse assunto ainda é controverso devido à heterogeneidade da madeira dentro da mesma espécie e pelo fato de alguns pesquisadores correlacionarem o rendimento de processo com os carboidratos da madeira, atribuindo à estrutura da lignina efeito secundário (MOKFIENSKI, 2004;GUERRA et al, 2008;FREITAS et al, 2018).…”