BASIC WOOD DENSITY, FIBER DIMENSIONS, AND WOOD CHEMICAL COMPOSITION OF FOUR Eucalyptus SPECIES PLANTED IN SOUTHERN BRAZIL

• Published in: Revista árvore 2023-01, Vol.47
• Main Authors: Bonfatti Júnior, Eraldo Antonio, Lengowski, Elaine Cristina, Cabral, Bruna Mulinari, Oliveira, Thiago Wendling Gonçalves de, Barros, Jeinna Michelly Rodrigues de, Oliveira, Rudson Silva, Andrade, Alan Sulato de, Klock, Umberto, Silva, Dimas Agostinho da
• Format: Article
• Language: English
• Subjects: Basic density; Fibers; FORESTRY; Wood chemistry
• ISSN: 0100-6762; 1806-9088; 1806-9088
• DOI: 10.1590/1806-908820230000004

ABSTRACT In the Brazilian planted forest sector, most of the species used are from the genus Eucalyptus. Even though Southern Brazil has a suitable climate for species of the genus Pinus, the planting of frost-resistant Eucalyptus species has been increasing annually. The objective of this study was to evaluate the basic density, fiber dimensions, and chemical composition of Eucalyptus benthamii, Eucalyptus dunnii, Eucalyptus saligna, and Eucalyptus cloeziana woods. The trees used were from a six-year-old experimental plantation located in Canoinhas, state of Santa Catarina. For each species, three trees were selected, and discs were removed from each tree at 0%, 25%, 50%, 75%, and 100% of the commercial stem height. To evaluate the quality of the wood, the basic wood density, fiber dimensions, and chemical composition of the wood were determined by comparing the values between species and between the heights in the stem. The highest basic density was that of the wood of E. cloeziana; this species also had the greatest length and width of fibers. E. dunnii had the lowest levels of lignin and the highest levels of holocellulose. The highest lignin content was found in the wood of E. benthamii, E. saligna, and E. cloeziana. The relationship between wood properties and stem height was not relevant. The results highlight the tendency for higher extractives to be found at taller heights (100%), and holocellulose and lignin content are similar at all heights. RESUMO No setor de florestas plantadas brasileiro, a maioria das espécies utilizadas são do gênero Eucalyptus. Embora o Sul do Brasil tenha clima propicio para espécies do gênero Pinus, o plantio de espécies de Eucalyptus resistentes à geada vem aumentando anualmente. O objetivo deste estudo foi avaliar a densidade básica, as dimensões das fibras e a composição química da madeira de Eucalyptus benthamii, Eucalyptus dunnii, Eucalyptus saligna e Eucalyptus cloeziana. As árvores utilizadas foram provenientes de um plantio experimental de seis anos localizado em Canoinhas, estado de Santa Catarina. Para cada espécie, três árvores foram selecionadas e os discos foram removidos de cada árvore a 0%, 25%, 50%, 75% e 100% da altura do caule comercial. Para avaliar a qualidade da madeira, a densidade básica, as dimensões das fibras e a composição química foram determinadas comparando-se os valores entre as espécies e entre as alturas no fuste. A maior densidade básica foi a da madeira de E. cloeziana; esta espécie ta