Impact of rotation length of Eucalyptus globulus Labill. on wood production, kraft pulping, and forest value

Abstract

Most of the wood from Eucalyptus globulus Labill. plantations in Uruguay is harvested for pulp industry at an average age of 11 years. In this study we evaluated the volume and quality of the wood produced and the economic return for owners using different rotation length (from 6 to 13 years) and two different provenances (Jeeralang, Australia and Chivilingo, Chile) in experimental plots planted at two different sites (southwest and southeast of Uruguay). Silvicultural practices, industrial process, and economic aspects of the plantations were evaluated by measuring the following variables: survival, individual and per hectare growth, basic density, cellulose yield, wood consumption, cellulose production per hectare, dry solids content, fiber length, paper resistance, internal rate of return, and soil expectation value. The results showed that an increase in the harvest age generates: (i) an increase in the production of wood and cellulose per hectare at decreasing rates; (ii) an increase in wood density and yield; (iii) a reduction in the consumption of wood and solid contents in the cooking liquor; and (iv) a reduction in economic profitability at the farm level. No differences were found in the fiber length and resistance properties of the paper from wood harvested at different ages.