Influence of spacing between trees on wood and charcoal quality indicators

ABSTRACT

Background:

The objective of this study was to evaluate the quality indicators for wood and charcoal from the Eucalyptus urophylla x Eucalyptus grandis hybrid (Clone GG 100) in different planting spacings. The study was conducted with the hybrid using the spacings of 2×1, 2×2, 3×2, and 3×3 m. The chemical properties of wood and charcoal were analyzed, and dry wood mass and energy per hectare were estimated. The data were subjected to the t test for comparison of means. Moreover, principal component analysis was conducted to assess the relationships between wood and charcoal indicators as a function of spacing.

Results:

The 2×2 m spacing showed the highest values for dry wood mass, lignin mass, mass of charcoal, and energy. The wider spacings of 3×2 and 3×3 m resulted in wood and charcoal of increased quality by showing wood of greater resistance to thermal degradation and charcoal of higher yield.

Conclusion:

Spacing between trees influenced wood quality indicators. The 2×2 m spacing showed higher estimates of mass and energy per hectare. However, wide spacings with an area greater than 6 m² are more suitable for charcoal production due to their superior wood properties, especially basic density and total lignin, which influence gravimetric yields and bulk density.

Keywords:
Eucalyptus; Wood quality; Biomass energy

HIGHLIGHTS

Tree spacing influenced the quality indices of wood and charcoal. Lignin and gravimetric yield show highest relative contributions for wood and charcoal. The 2×2 m spacing presented higher estimates of mass and energy per hectare. Wider spacings (> 6 m2) are the most suitable to produce charcoal.