Wood and pulp properties of four New South Wales provenances of Eucalyptus nitens grown on a warm and a cold site in South Africa

Eucalyptus nitens is considered of minor importance as it covers only 150,000 ha of plantation forestry worldwide. However, it is extensively planted in the colder areas of countries such as Chile, Australia and South Africa because of tolerance to frosts and snow coupled with fast growth. Thirty six, six-year-old trees representing four New South Wales provenances planted in species/ provenance trials on a cold and a warm site (mean annual temperatures of 14.8 and 16.0 degrees C) in South Africa are evaluated in this paper for wood and kraft pulp properties. In comparison to the E. grandis control in the trial (Coffs Harbour provenance), E. nitens was found to have a high pulp yield that was stable across sites, higher brightness, higher wood density and slightly faster cooking time. Although there was very little difference in tear strength between the two species, E. nitens had superior burst strength. The alpha cellulose was similar, hemicellulose content higher and lignin lower for E, nitens, while E. grandis had a longer fibre length. Apart from density, extractives content and alkali content, differences between the two trial sites had very little effect on the wood and pulp properties of E. nitens. These results suggest that E. nitens is an exceptional hardwood species for kraft pulping, and in particular for the manufacture of fine papers where burst strength and high brightness are important.