Drying of eucalyptus logs from plantations with different spacing between trees

Abstract

The adoption of dense plantations can reduce the drying time of the logs, by optimizing this step. This study evaluated the drying of eucalyptus wood from plantations with different spacing (3 × 4; 3 × 3; 2 × 3; 1 × 3 m). Five trees were selected per treatment. Logs were removed from the base and at 50% and 100% of commercial height for drying evaluation for 60 days. The diameters of the eucalyptus trees from plantations with wider spacing were bigger, and the productivity per hectare was not affected by the spacing between trees. The planting spacing did not affect the initial moisture, which was higher for those removed from the top of the trees. The logs from the base from the denser spacing showed a drying rate 2.5 times higher than the same logs from the treatment with greater spacing, reducing the final moisture from 37.2 to 18.8%. The logs removed from the top of the trees reached the equilibrium moisture after the drying period. The reduction in the planting spacing reduced the wood moisture and the difference in this parameter between the logs removed from the base and top of the eucalyptus trunks.

Field Drying for Enhancing Biomass Quality of Eucalyptus Logs and Trees in Florida, USA

“…Both E. grandis and E. amplifolia lost moisture at a higher rate in the first month (Table 5, Figure 6) which is consistent with the observations in other studies [29,30]. The average MC od in E. grandis ranged between 63.5 and 86.1% in the first month and between 70.7 and 102.1% in E. amplifolia.…”

“…Each core was next weighed in the field and then dried in the lab at 101 °C until a constant weight was observed (Figure 2). After drying, core dry weights were taken, and MCod at the time of sampling was calculated on an oven dry weight (ODW) basis [29,30] In each season, stem cores were collected approximately monthly for two months after the season began. On each sampling date (Table 3), 12 mm diameter cores (barkto-bark) were extracted from the middle of 2.4 m logs and corresponding stem positions (approximately 1.2, 3.6, 6, 8.5, 11, 13.5, 15.8, and 18.2 m heights = stem core positions 0, 1, 2, 3, 4, 5, 6, and 7, respectively) on whole trees using a powered increment borer.…”

“…Each core was next weighed in the field and then dried in the lab at 101 • C until a constant weight was observed (Figure 2). After drying, core dry weights were taken, and MC od at the time of sampling was calculated on an oven dry weight (ODW) basis [29,30] as follows:…”

“…), sweetgum (Liquidambar styraciflua L.), and yellow poplar (Liriodendron tulipifera L.) [8]. Most of the free water is removed during this initial drying period due to the weak capillary force holding it [30,36]. Eucalyptus wood tends to have relatively more free water.…”

“…In E. amplifolia, the highest loss of 33.4% was observed at position 3. Higher moisture loss from small diameter stems or smaller wood samples is expected because water has to travel less distance from inside the wood to the surface [26,29,30]. In addition, tree tops are dominated by sapwood resulting in higher water storage but faster water flow [30,37,38].…”