ENVIRONMENTAL EFFECT ON CHEMICAL COMPOSITION OF EUCALYPTUS CLONES WOOD FOR PULP PRODUCTION

Abstract

This current research aimed to evaluate the environment effect on the wood chemical composition of Eucalyptus grandis x Eucalyptus urophylla clones to pulp production. Seven clones of 6.5 years old were evaluated. It was planted in two growing sites, Nova Almeida – Espírito Santo and Posto da Mata – Bahia stablished in 3 x 3 m spacing. Five trees were selected from each clone and discs were removed from five different positions equidistant from the trunk and the diameter at breast height (DBH) height. From those were obtained two wedge in opposite ways. The chemical analysis was performed with a sample composed of all the wedges of each tree, for the determination of 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 one least influenced by the growth site. For the wood extractive content, most of the studied clones presented a statistical difference between the growing site, as opposed to the total carbohydrates content that was highlighted by presenting values little influenced by the genetic material and the growth site.