The Brazilian bioenergy industry is well developed and has numerous highly productive Eucalyptus spp. clones, the wood of which may suit the timber industry. We screened the mechanical wood properties of six bioenergy Eucalyptus spp. clones from young forests to find ones suitable for the timber industry. We evaluated shear strength, parallel compressive strength, strength and stiffness on static bending, and wood density. Eucalyptus camaldulensis clones had low strength and stiffness for their wood density and are less suitable for timber products. However, clones from E. urophylla and E. urophylla × E. grandis had specific strength and stiffness close to the values reported for mature Eucalyptus wood. Their average density ranged from 0.54 g cm⁻³ to 0.68 g cm⁻³ and, while the lightest wood had properties close to those of mature Pinus elliottii trees, the clone with the densest wood produced material similar to mature E. urophylla. We conclude that these clones have distinct wood properties, each with different potential applications. With better understanding of this timber source, young clonal Eucalyptus forests could be an asset to the timber industry in Brazil, substituting pine wood and providing raw material close to the main consumer markets.

Branch wood presents potential volumetry that may have several applications, and its use may improve forest management efficiency in the Amazon. However, there is a lack of knowledge regarding the properties of branch wood when compared to the stem or what its potential applications might be, considering the possible variability of wood formation in branches. This study aimed to characterize physically and mechanically the branch wood of Dipteryx odorata, Hymenolobium petraeum and Hymenaea courbaril and to compare them with their respective stems. No significant statistical differences were observed for the basic density between the branch and stem woods. The branch wood of Dipteryx odorata and Hymenaea courbaril showed a lower coefficient of anisotropy (1.23 and 1.99, respectively) than the stem wood (1.62 and 2.49, respectively). D. odorata showed similar mechanical properties between the branch and stem, except for hardness, while H. petraeum and H. courbaril branch wood showed lower strengths when compared to the stem wood for all mechanical tests, except for the shear strength test. Branch wood has similar potential uses to stem wood and can be used for non-structural purposes such as small artifacts, decorative items, furniture, tools and panels composed of short, glued pieces.

The use of intensive silviculture to increase forest productivity in commercial plantations will undoubtedly persist into the future. This review synthesizes and analyses studies that have investigated the influence of fertilization on density, microfibril angle (MFA), and modulus of elasticity (MOE) of different Pinus species under intensive management. It was found that in general, ring width or growth rate demonstrated a negative correlation with density, and a positive relationship with MFA. Also, the relationship between growth rate and density and MFA were age specific and often non-significant at the whole stem level. Earlywood and latewood were influenced differently by fertilization: Earlywood width and density increased while in latewood, width stayed constant but density decreased. This resulted in a decrease in within-ring heterogeneity of density and density-related properties. Since latewood generally contributed more to whole-ring density, the net effect was that whole-ring wood density of pines mostly decreased with fertilization. Given that fertilization often resulted in a decrease in wood density and an increase in MFA, MOE decreased with fertilization. Most fertilization-wood-property studies on Pinus involved nitrogen and phosphorus fertilizers with differing quantity and ratios. Results suggest that nitrogen may cause the greatest change in wood growth and properties. An important question that was often unanswered in research, was whether the effect of specific fertilization treatments on wood properties were purely based on the influence of increased growth or whether there were direct influences not explained by growth. Also, despite potassium being an important elemental component of many fertilizers, relatively little work has been done to determine its effect on wood properties.

Due to changes in the Amazon forest dynamics after the first cutting cycle, non exploited species become dominant in the forest. The lack of technological knowledge makes it hard to commercialize these woods, making the understanding of their physical-mechanical properties a fundamental step to properly define their applications. This study aimed to characterize physically and mechanically the wood of Pseudopiptadenia psilostachya and Eschweilera ovata from the second cutting cycle of the Tapajós National Forest, intending to commercially promote and to identify usages for them, as well as to evaluate the viability of replacement of highly commercialized species. The tests were performed accordingly to the Brazilian standard NBR 7190. P. psilostachya, presented bulk density of 0.683 g.cm^-3, medium levels of shrinkage and anisotropy, as well as medium hardness (7366 N) and high strength on compression parallel to grain (71.63 MPa) and on static bending (103.9 MPa). It was generally superior to Euxylophora paraensis, but inferior when compared to Bagasssa guianensis and Apuleia leiocarpa, with possibilities to replace these three species. E. ovata, on the other hand, presented bulk density of 0.798 g.cm^-3, high shrinkage and anisotropy values, but high values for hardness (12089 N) and strength on compression parallel to grain (68.67 MPa) and on static bending (127.1 MPa). This species exhibited, in general, similarities with Mezilaurus itauba, although it is a little inferior in relation to Hymenaea sp. and Astronium lecointei. Both species, P. psilostachya and E. ovata fit in the highest strength class described on the Brazilian Standard NBR7190, C60. By means of the results found, it was concluded that although the species studied were unknown, they presented timber with enough quality to replace some Amazon timber species widely commercialized on both national and international market.