Branches remain in the forest environment as logging activity residue. Considering the large size of many Amazonian trees, their branches have considerable dimensions and can contribute to a sustainable wood alternative for various applications. Due to the formation of reaction wood in the branches, relevant macro and ultrastructural changes can occur in its characteristics in relation to the trunk wood. However, the woods of the branches are not technologically well known. Therefore, this work aimed to evaluate the wood quality of branches of Hymenaea courbaril L., comparing it with wood of trunks. The extractives and lignin contents, basic density, shrinkage, fiber biometry, microfibril angle and mechanical resistance to compression parallel to the fibers were analyzed. The branch wood had smaller fiber dimensions and a higher microfibril angle than the trunk wood. The basic density was similar between these materials. The linear and volumetric shrinkages were smaller in the branch wood than in the trunk, while the axial shrinkage was higher in the branch. The parallel compressive strength was also lower in the branch wood than in the trunk. The branch wood has properties suitable for products with higher added value such as furniture, decorative objects, floors and utensils in general.

Brazil is one of the largest producers of tropical wood in the world. Much of this wood is extracted from the Amazon region, especially in the state of Pará. Despite empirical knowledge, there is little information in the literature about the selectivity of trade and how this production has been behaving in recent years. Is there any relationship between this legal timber trade and deforestation? In this work, we compile data reports from control agencies and analyze the dynamics of the legal timber market in the state of Pará between 2009 and 2015 in terms of species, volume, and monetary value. We also correlate changes in volume m⁻³ and value m⁻³ with deforestation increase in the same period and region. We find that only ten groups of species represent almost 50% of the total timber volume marketed in the State, mainly from the Massaranduba (Manilkara) group. According to our models, the supply of a species of wood on the market is defined by its monetary value and not by its availability or characteristics, which hinders the insertion of new species and increases selectivity. Since 2011 the volume of legally traded logs has been decreasing sharply. Traditional forest regions in the state already demonstrate depletion in forested areas. While others, such as the lower Amazon region, have been increasing production, showing that new forestry operations areas are being used for harvesting in the function of the lower availability in traditional areas. Our models show that the legal reduced impact logging timber volume has an inverse relationship with the deforestation increase. Otherwise, preference for a small group of timber types still predominates, which may lead local woods to the danger of extinction.

The study aimed to analyze the physical and mechanical properties of charcoal from eucalyptus clones by principal component analysis and demonstrate the relationships between these properties, in order to assess which charcoal property should aimed in the process to obtain a higher quality product. In this way, was cut eight clones of Eucalyptus and two of Corymbia, collecting three trees per clone and five disk in different heights. The disks were transformed into test samples, totaling an average of 75 samples per clones, which were carbonized under specific conditions for analysis of apparent density, compressive strength parallel to grain and linear and volumetric degradation due to high temperature. It is noteworthy that the data were weighted by disk and per tree, to an average closer to reality. For correlations, was used multivariate analysis of principal components. Herein, it is found that the apparent density of charcoal acts as the focal point of the other properties studied, and observed that as the higher the density, higher will be the compressive strength parallel to grain, the elastic modulus and the gravimetric yield.

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 objective of this study was to evaluate the composition of OSB panels created using the Amazonian species Caryocar villosum Aubl., Erisma uncinatum Warm., and Hymenolobium excelsum Ducke. The OSB was produced using a phenol–formaldehyde adhesive at a ratio of 30:40:30 for each layer. Different mixtures of Amazonian wood and Pinus caribaea var. caribaea. were tested. Physical (water absorption and thickness swelling after 2 and 24 h of immersion in water and non-return rate in thickness) and mechanical (internal bond and parallel and perpendicular static bending) tests were performed. The OSB panels composed of wood mixtures absorbed less water after 2 and 24 h of immersion when compared to the OSB produced using pine wood. After 24 h of immersion in water, the T3 panel (40% Pinus caribaea + 40% Hymenolobium excelsum + 20% Caryocar villosum) presented the lowest absorption value. In terms of swelling in thickness at 2 h and 24 h, the panel composed of 100% pine strands showed the highest swelling value, while the T3 treatment exhibited the lowest swelling value at 2 and 24 h, as well as for the rate of non-return in thickness. Regarding mechanical properties, we observed that all panels exhibited similar resistance for both parallel and perpendicular Modulus of Rupture, as well as parallel and perpendicular Modulus of Elasticity, except for the internal bond, where T3 demonstrated the highest resistance. Additionally, some OSB panels met the requirements of the EN 300 standard for OSB panels.

With few measurement sites and a great need to validate satellite data to characterize the exchange of energy and carbon fluxes in tropical forest areas, quantified by the Net Ecosystem Exchange (NEE) and associated with phenological measurements, there is an increasing need for studies aimed at characterizing the Amazonian environment in its biosphere–atmosphere interaction, considering the accelerated deforestation in recent years. Using data from a flux measurement tower in the Caxiuanã-PA forest (2005–2008), climatic data, CO₂ exchange estimated by eddy covariance, as well as Gross Primary Productivity (GPP) data and satellite vegetation indices (from MODIS), this work aimed to describe the site’s energy, climatic and carbon cycle flux patterns, correlating its gross primary productivity with satellite vegetation indices. The results found were: (1) marked seasonality of climatic variables and energy flows, with evapotranspiration and air temperature on the site following the annual march of solar radiation and precipitation; (2) energy fluxes in phase and dependent on available energy; (3) the site as a carbon sink (−569.7 ± 444.9 gC m⁻² year⁻¹), with intensity varying according to the site’s annual water availability; (4) low correlation between productivity data and vegetation indices, corroborating data in the literature on these variables in this type of ecosystem. The results show the importance of preserving this type of environment for the mitigation of global warming and the need to improve satellite estimates for this region. NDVI and EVI patterns follow radiative availability, as does LAI, but without direct capture related to GPP data, which correlates better with satellite data only in the months with the highest LAI. The results show the significant difference at a point measurement to a satellite interpolation, presenting how important preserving any type of environment is, even related to its size, for the global climate balance, and also the need to improve satellite estimates for smaller areas.