Variation in whole-tree basic wood density for a range of plantation species grown in New Zealand.

Whole-tree basic wood density of individual trees of a variety of species has been determined in many different studies in New Zealand since 1977. These data were recently collated, and whole-tree values for each species have been aggregated across sites into 5-year age-classes, from <7 years up to 70 years. Means, ranges, and standard deviations of each species/age-class have been tabulated for a total of 968 trees and 13 species or species groups, with numbers of trees/species varying from 15 to 232. Sites sampled were mainly in the central and northern parts of the North Island (latitude 39°30 '-35°25 S). Logarithmic regression equations fitted to the age-class mean densities for each species have provided predictions of whole-tree basic density with age and, in conjunction with predicted volume yields, were used in a related study to predict stem dry matter production per hectare for different species. The species included were: Acacia dealbata Link., A. mearnsii De Wild., cypresses (data from Chamaecyparis lawsoniana (Murray) Pari, Ch. nootkatensis (D.Don) Spach x Cupressus macrocarpa, C lusitanica Miller, and C. macrocarpa Gordon were amalgamated), Pseudotsuga menziesii (Mirbel.) Franco, Eucalyptus fastigata Deane et Maiden, E. globoidea Blakely, E. globulus Labill., E. maidenii Labill., E. muelleriana Howitt, E. nitens (Deane et Maiden) Maiden, E. pilularis Smith, E. regnans F.Mueller, and E. saligna Smith. Predicted mean whole-tree basic density (from logarithmic regression) for the eucalypts (30-year-old trees) varied from 452 kg/m3 for E. regnans to 623 kg/m3 for E. globoidea. No data at age 30 years were available for Acacia mearnsii and E. maidenii but their mean density was respectively 658 kg/m3 at age 14 and 572 kg/m3 at age 11 years. Whole-tree mean density was about 418 kg/m3 for the cypresses and 406 kg/m3 for Ps. menziesii, almost irrespective of tree age.