Variation in wood, kraft fibre, and handsheet properties among 29 trees of Eucalyptus regnans, and comparison with e. nitens and e. fastigata

Variation in and relationships between wood, chemical, kraft fibre, and kraft handsheet properties were studied in 29 individual trees of Eucalyptus regnans F. Mueller, aged 20-21 years, grown in Kaingaroa Forest, New Zealand. Means and ranges of these characteristics for E. regnans were also compared with those for similar 29-tree samples from E. nitens (Deane et Maiden) Maiden and E. fastigata Deane et Maiden from the same forest, aged 15-16 years. The trees sampled of E. regnans were of lower wood density (in spite of their greater age) and had kraft fibres that were longer, broader, thinner-walled, and had higher levels of collapse than those of either of the other species. Eucalyptus regnans individual-tree pulps showed the widest range of apparent sheet density compared with the other two species but had a similar mean, which was well predicted by wood density or by the level of fibre collapse in handsheets. Eucalyptus regnans trees had a good pulp yield, similar to those of E. nitens. For a market kraft pulp, E. regnans grown for 15 years could be expected to give a kraft pulp very deficient in handsheet bulk.