The use of wood in the form of charcoal for energy production, has great economic importance in Brazil. In this context, the study of variables and mechanisms that affect charcoal quality is essential. The present study aimed to verify the influence of some physical properties of Eucalyptus wood on the quality and yield of the produced bioreducer. We used three commercial Eucalyptus clones, cultivated for use in the steel industry, determining wood density and shrinkage, density and immediate chemistry of the charcoal produced and the charcoal gravimetric yield. The data was submitted to Pearson’s correlation analysis. Correlations between wood density and apparent charcoal density as well as charcoal ash content were observed. All clones presented characteristics suitable for the production of charcoal for the steel industry, with emphasis on the hybrid E. urophylla x E. grandis.

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.

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.

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.

Half of the Amazon Forest, which has a marked seasonality in rainfall, is susceptible to intense droughts caused by positive phases of the El Niño-Southern Oscillation (ENSO). Cedrela odorata L., sensitive to climate variations, emerges as a promising candidate for studies on how trees respond to climate change. Given the demand for its wood and the imperative for its protection in the Amazon Biome, applying the principles of environmental sustainability becomes crucial. This study characterizes local climatic variables near the Amazon River and assesses their impact, as well as the effect of ENSO, on the radial growth of Cedrela odorata using Pearson correlation analyses. Ring synchronization followed the standard methodology in dendrochronology, confirming common growth patterns and the formation of growth rings in C. odorata. Significant correlations with growth were noted concerning local climate, with negative associations for maximum and average temperatures and evapotranspiration, and a positive correlation with relative air humidity. ENSO exhibited a significant negative correlation with growth rings, indicating reduced growth during El Niño events. The species is notably sensitive to water availability, particularly at the onset of the growth period. The study concludes that the growth of C. odorata in the Óbidos-PA microregion responds to climate change.