Variation of Wood Pulping and Bleached Pulp Properties Along the Stem in Mature Eucalyptus globulus Trees

The wood of a mature (40-year-old) Eucalyptus globulus Labill tree was characterized at different stem height levels (0%, 10%, 35%, and 50% of total height) regarding pulping, bleaching, and paper properties. Pulp yields increased upwards from 46% to 50%, and Kappa number decreased from 17.5 to 12.3 at 0 and 50% height, respectively. The estimated specific wood consumption ranged from 3.2 m odt to 3.1 m odt at 0% and 50% height levels, respectively. Pulp drainage varied along the stem, with less drainability (20.3 oSR) and higher water retention value (1.07 g.g) at the base. Pulp fiber length increased (827 μm vs. 877 μm) and width decreased (19 μm vs. 17 μm) from 0% to 50% height levels. Tensile, tear, and internal bond strength decreased upwards, with mean values of 34.9 N.m.g, 3.1 mN.m.g, and 95.8 J.m, respectively. These findings support the use of mature E. globulus trees without loss of pulp production and quality.