Variations in heartwood formation and wood density as a function of age and plant spacing in a fast-growing eucalyptus plantation

The heartwood formation process is little known in fast growing plantation woods. Therefore, the aims of this study were to determine how planting spacing and tree age affect the formation and proportion of heartwood and sapwood, as well as the density of eucalyptus wood. Trees from a eucalyptus clonal plantation (Eucalyptus grandis × E. urophylla hybrid) cultivated in three spacings (3 × 1, 3 × 2 and 3 × 3 m) were sampled at 14, 27, 32, 53, 64 and 76 months of age. Heartwood percentage was quantified with Dimethyl yellow indicator, while the wood density was determined by X-ray densitometry. The heartwood percentage, wood volume, heartwood density and wood density were correlated with the different growth rates. The heartwood formation process started between 32 and 53 months, regardless of spacing. The heartwood proportion doubled with increasing age in the widest spacing and increased about four times in 3 × 1 and 3 × 2 m spacing. The planting spacing influenced the growth rates of the trees, but did not affect the heartwood and sapwood percentage or density. The greatest increase in density values occurred between the first year of growth (14 months) and the beginning of heartwood formation (53 months).

Variation of Heartwood Proportion and Wood Colour from Fast Grown 5-Year-Old Teak

The heartwood percentage and wood colour of fast plantation grown teak destined for harvest at 5 years of age were characterized using automatic image processing ’ImageJ’ routines and CieLab’s colour system with the following coefficients: L for lightness, a* for redness and b* for yellowness. Analyses were conducted on material from different dry and wet sites. Comparison with 6-year old plantation from a dry site was conducted to study differences arising in older trees. Analyses of variation of those properties between and within different tree diameter classes were also conducted. The results showed that brightness, redness and yellowness values of 5-year old teak trees were 60.7, 10.7 and 23.1, respectively. Tree clone had a more dominant effect on wood colour and heartwood proportion than site, thus if specific colour preferences are needed of plantation trees, clone selection is important. The drier site produced larger proportions of heartwood in trees, as well as a more attractive figure. The trees produced heartwood proportions of 20% and 14% from the dry and wet sites respectively. On average, these 5 year old teak trees already produced 18% heartwood. Faster tree growth (larger diameter) appeared to have produced significantly larger heartwood proportions. Radially, the palest colour (the highest L but the lowest a*b* parameters) occurred in an area between heartwood and sapwood indicating the presence of a transition zone in all the tree samples.

Effects of Density Control and Fertilization on Log Wood Quality from a Douglas-fir Stand in Western Oregon, USA

This study aimed to investigate the effects of juvenile spacing (precommercial thinning), thinning, and fertilization on Douglas-fir butt log (first 4.9 m) and second log (4.9–10 m) quality attributes: juvenile wood percentage, heartwood percentage, rings per inch, specific gravity, and modulus of elasticity. A 41-year-old, 36.6 m site index Douglas-fir stand in western Oregon, USA was selected as the first stand to explore. Nine common silviculture pathway treatments of juvenile spacing, thinning, and fertilization were applied to independent 0.404-hectare plots. Ninety-nine trees were felled and disks cut at five heights along the stem. Wood properties were measured and calculated from the disks for log quality attributes. There was no effect of silvicultural treatments on log heartwood percentage, but significant effects on other log quality attributes were observed. Juvenile wood percentage and rings per inch declined with stand density control and fertilization treatment. Responses to thinning and fertilization in log specific gravity depend on juvenile spacing. Also, thinning and juvenile spacing were shown to have impacts on log modulus of elasticity.

Effect Of Planting Spacing In Production And Permeability Of Heartwood And Sapwood Of Eucalyptus Wood

ABSTRACT The objective of this work was to evaluate the influence of different useful areas provided by the planting spacings (3 × 1, 3 × 2, 3 × 3, 3 × 4 m) on the production and permeability of heartwood and sapwood of Eucalyptus grandis and Eucalyptus grandis × Eucalyptus urophylla clones at 4 years old. Regardless of the clone, there was no effect of planting spacing on the heartwood/sapwood relation and wood permeability. All clones showed a heartwood decrease with increased height, regardless of planting spacing, and E. grandis (B) was the only one that had its heartwood percentage positively and significantly correlated with the dendrometric variables (DBH and commercial height). The use of the dymethil yellow compound was indispensable in defining the heartwood and sapwood regions in the samples from 50% of the stem height. The heartwood permeability was low in all evaluated clones, suggesting vessel obstruction by tyloses or other deposits, while sapwood permeability reached 405.4 cm3/cm.atm.s.

Inheritance Pattern of Growth and Wood Traits in Teak (Tectona grandis L.f.).

Inheritance pattern of wood traits, especially heartwood/ sapwood percentage and specific gravity and interactions of wood traits with other growth traits were investigated in a 27-year-old half-sib progeny trial of teak. Wood traits showed highly significant variation for specific gravity, heartwood and sapwood percentage at family level. There was non-significant family vs. replication variation for these traits. Among the growth traits, there was significant variation for height and girth. Families and individual trees showed varying levels of heritability. Among the growth traits, height showed high heritability (individual tree heritability, h2 (i) = 34.3%; family heritability, h2 (f ) = 34.1%) followed by girth (h2 (i) = 19.4%; h2 (f ) = 31.4%). Among the wood traits, maximum heritability values were obtained for sapwood percentage (h2 (i) = 76.6%; h2 (f ) = 70.7%) and heartwood percentage (h2 (i) = 76.9%; h2 (f ) = 69.7%). Specific gravity exhibited heritability values of 29.1 and 41.8%, at individual tree and family level, respectively. Family heritability was higher than single-tree heritability for specific gravity; single-tree heritability exceeded family heritability for heartwood percentage. Specific gravity exhibited significant positive genotypic correlation with heartwood percentage suggesting that improvement in heartwood percentage would lead to a correlated improvement in specific gravity. Heartwood percentage showed significant positive correlation with growth traits viz., height and girth. Some of the families showed good GCA for growth and wood traits investigated. The good general combiners identified in the present study can be used for establishment of advanced generation seed orchards and breeding arboreta for improvement of teak for specific or combination of above traits.