Abstract Introduction: The great diversity of tropical timber species demands the development of new technologies capable of identifying them based on their patterns or anatomical characteristics. The application of convolutional neural networks (CNN) for the recognition of tropical timber species has increased in recent years due to the promising results of CNNs. Objective: To evaluate the quality of macroscopic images with three cutting tools to improve the visualization and distinction of anatomical features in the CNN model training. Methods: Samples were collected from 2020 to 2021 in areas of logging and sawmills in the Central Jungle, Peru. They were later sized and, after botanical and anatomical identification, cut in cross sections. A database of macroscopic images of the cross-section of wood was generated through cutting with three different tools and observing its performance in the laboratory, field, and checkpoint. Results: Using three cutting tools, we obtained high quality images of the cross section of wood; 3 750 macroscopic images were obtained with a portable microscope and correspond to 25 timber species. We found the ''Tramontina'' knife to be durable, however, it loses its edge easily and requires a sharpening tool, the ''Pretul'' retractable cutter is suitable for cutting soft and hard wood in small laboratory samples and finally the ''Ubermann'' knife is suitable for use in the field, laboratory, and checkpoint, because it has a durable sheath and interchangeable blades in case of dullness. Conclusion: The quality of the images is decisive in the classification of timber species, because it allows a better visualization and distinction of the anatomical characteristics in training with the EfficientNet B0 and Custom Vision convolutional neural network models, which was evidenced in the precision metrics.

Resumen Introducción: La gran diversidad de especies maderables tropicales demanda el desarrollo de nuevas tecnologías de identificación con base en sus patrones o características anatómicas. La aplicación de redes neuronales convolucionales (CNN) para el reconocimiento de especies maderables tropicales se ha incrementado en los últimos años por sus resultados prometedores. Objetivo: Evaluamos la calidad de las imágenes macroscópicas con tres herramientas de corte para mejorar la visualización y distinción de las características anatómicas en el entrenamiento del modelo CNN. Métodos: Recolectamos las muestras entre el 2020 y 2021 en áreas de explotación forestal y aserraderos de Selva Central, Perú. Luego, las dimensionamos y, previo a la identificación botánica y anatómica, las cortamos en secciones transversales. Generamos una base de datos de imágenes macroscópicas de la sección transversal de la madera, a través del corte, con tres herramientas para ver su rendimiento en el laboratorio, campo y puesto de control. Resultados: Usamos tres herramientas de corte para obtener una alta calidad de imágenes transversales de la madera; obtuvimos 3 750 imágenes macroscópicas con un microscopio portátil que corresponden a 25 especies maderables. El cuchillo ''Tramontina'' es duradero, pero pierde el filo con facilidad y se necesita una herramienta para afilar, el cúter retráctil ''Pretul'' es adecuado para madera suave y dura en muestras pequeñas de laboratorio; el cuchillo ''Ubermann'' es apropiado para el campo, laboratorio y puesto de control, porque tiene una envoltura duradera y láminas intercambiables en caso de pérdida de filo. Conclusiones: La calidad de las imágenes es decisiva en la clasificación de especies maderables, porque permite una mejor visualización y distinción de las características anatómicas en el entrenamiento con los modelos de red neuronal convolucional EfficientNet B0 y Custom Vision, lo cual se evidenció en las métricas de precisión.

ABSTRACT Background: The biodiversity of the Peruvian Amazon tropical forests is one of the most expressive in the world, with 2500 forest species, although restricted to about 250 tree species used commercially. This species diversity indicates the challenge magnitude for research in taxonomy and timber species identification. Likewise, it implies the complexity of biodiversity conservation and restoration measures, which are directly related to the control of deforestation, cutting and transport of illegal wood. With this objective, the present study describes the macroscopic wood anatomical features in order to identify 20 tree species from Peruvian Amazon Forest, “Selva Central”, including an identification key and tree species botanical validation. Results: The wood species are included in 12 families commonly found in the tropical forests of Peru, highlighting the Fabaceae (25%), Moraceae (15%), Podocarpaceae and Lauraceae (10%) families and are sold as timber for several uses and applications in the internal market and for export. The wood species presented common anatomical features, such as diffuse porosity, visible axial parenchyma mainly distinct, and, eventually, with ray storied, e. g: A. cearensis, M. balsamum and M. peruiferum. Conclusion: The tropical tree species identification is possible by analyzing their wood macroscopic anatomical structure. The results can be also applied in the wood trade traceability by controlling deforestation and illegal wood commerce and in proposing policies for biodiversity conservation and sustainable use of natural resources. They constitute, likewise, a database for the recent wood identification methodologies presented in the specialized literature.

ABSTRACT Background: Knowledge of the anatomy and properties of wood help to understand the quality of wood and plan its ideal technological use, therefore, it is necessary to understand the variations in wood characteristics and properties. Here we evaluate the radial variation of wood density and fiber morphology of two commercial forest species in a tropical humid forest of the department of Madre de Dios in Peru: Jacaranda copaia and Hura crepitans collected in a management area. Results: Forestry collecting 10 usable trees by species. We provide general values of the densities and fibers of the two species studied. Conclusions: Regarding the variation of the radial density, J. copaia presented a density growth in the pith-bark direction, while for H. crepitans its variation was not significant, these variations are clearly explained by the morphology of its fibers.

Resumen: En el presente trabajo se determinaron los parámetros colorimétricos mediante el sistema CIELAB y la densidad aparente por densitometría de rayos X en madera de Guazuma crinita para obtener información de su calidad en el uso como madera solida o transformada. La evaluación se realizó en tres niveles del eje axial (basal, medio y apical) de una plantación de 5 y 8 años, en la zona de Puerto Inca, departamento de Huánuco, Perú. En ambas edades, empleando el sistema CIElab, se encontró que la madera es de coloración homogénea y se clasifica como rosa grisáceo. La densidad aparente medida por densitometría de rayos X en el sentido médula - corteza fue de 520 kg/m3 y 560 kg/m3 para 5 y 8 años respectivamente; con promedios mayores en el nivel basal (5 años: 650 kg/m3; 8 años:680 kg/m3) y menores en el nivel apical (5 años: 430 kg/m3; 8 años: 470 kg/m3). Los perfiles densitométricos mostraron, en general, que radialmente hay un aumento de la densidad aparente en el sentido médula - corteza. La densidad de la madera madera de 5 años resultó más uniforme que la de 8 años con un índice de uniformidad de 149,7 y 170,3, respectivamente.

Abstract: In the present work, the colorimetric parameters were determined using the CIELAB system and the apparent density by X-ray densitometry in Guazuma crinita Mart. wood to obtain information of its quality in use as solid or transformed wood. The evaluation was carried out in three levels of the axial axis (base, medium, apical) of one plantation of 5 and 8 years old, in Puerto Inca, department of Huánuco, Peru. It was found that in both ages, according to CIElab system, the wood is of homogeneous coloration and is classified as greyish pink. The apparent density measured by X ray densitometry in the pith - bark direction was found to be 520 kg/m3 and 560 kg/m3 for 5 and 8 years, respectively; with higher values at the basal level (5 years old: 650 kg/m3; 8 years old: 680 kg/m3) and lower towards the apical part (5 years old: 430 kg/m3; 8 years old: 470 kg/m3). The densitometric profiles showed, in general, that there is an increase in apparent density radially in the pith-bark direction. The 5-year-old wood density was more uniform than the 8-year-old one with a uniformity index of 149,7 and 170,3, respectively.

Abstract: This study set out to determine which environmental factors of growth and silvicultural practices can affect the properties of Eucalyptus robusta coppice wood and also to study variability in those properties depending on the factors. Hundred and thirty-five coppice logs aged 2 to 10 years were collected from five zones in the Highlands of Madagascar. Wood density at 12% moisture content was measured by X-ray microdensitometry. Chemical properties, such as the total extractives, Klason lignin and holocellulose contents were predicted using near infrared spectrometry prediction models. The results significantly showed (p-value<0,001) that wood density (543 - 836 kg/m3), total extractives (3,1 - 9,8%) and Klason lignin content (24,6 - 35,3%) increased with age, with the opposite occurring for holocellulose (63,8 - 69,9%). Wood density also varied significantly (p-value<0,001) depending on the zones, which was not the case for chemical properties. The densest woods were found at the hottest zones with less acid soils. Woods were less dense in zones, characterized by high rainfall and a soil rich in nitrogen and organic carbon. The plantation spacing, elevation of the zone and soil texture did not significantly affect wood properties.

Abstract: The aim of the present study was to determine the physical properties of the Guazuma crinita wood by conventional methods, as well as to estimate these properties by near infrared spectroscopy (NIR) through the development of multivariate calibration models. The samples were obtained from five trees and from three levels longitudinally for 5 and 8 years of age randomly selected from a plantation in Puerto Inca, Department of Huánuco (Perú). Basic density, volumetric, tangential and radial contraction were determined by the conventional methods. Models were developed by regression of partial least squares (PLS) through mathematical transformations. For the validation of the models, a new group of samples -which did not participate in the development of the model were used. Statistical significance was found F 5años = 191,5; F 8 años =84,9) between the different heights in the stem. Basic density and volumetric contraction show values of (0,88 and 0,83) and RPDp (1,55 and 3,27) acceptable for prediction.

Resumen: El objetivo del presente estudio fue determinar las propiedades físicas de la madera de Guazuma crinita por el método convencional, así como estimar estas propiedades por espectroscopia infrarroja cercana (NIR) a través del desarrollo de modelos de calibración multivariada. Las muestras fueron obtenidas de tres niveles del eje longitudinal en 5 árboles para 5 y 8 años de edad seleccionados al azar de una plantación en la zona de Puerto Inca, departamento de Huánuco (Perú). Se determinó la densidad básica, contracción total volumétrica, tangencial y radial por el método destructivo o convencional. Los modelos fueron desarrollados por regresión de mínimos cuadrados parciales (PLS) mediante transformaciones matemáticas. Para la validación de los modelos se empleó un grupo de muestras que no participo en el desarrollo del modelo. Se encontró diferencias estadísticas significativas (F 5años = 191,5; F 8años =84,9) entre las tres alturas en el fuste. Para densidad básica y contracción volumétrica se encontró valores de (0,88 y 0,83) y RPDp (1,55 y 3,27) aceptables para la predicción.

ABSTRACT The Atlantic Forest of southeastern Brazil has been considered to have the highest number of tree species per hectare in the world. Assessing the influence of climate on tropical tree species is a priority in the face of ongoing climate change, and for which dendrochronological studies have been important. We address the dendrochronological potential of Licaria bahiana Kurz (Lauraceae), an endemic species of the Atlantic forests. We studied growth ring anatomy of L. bahiana and applied dendrochronological methods to investigate how short-term variation in climate affect its radial growth. Distinct growth rings were observed in all individuals and demarcated by darker tangential fiber zones in latewood. Trees showed high climatic sensitivity (0.48) and growth synchrony (intercorrelation r = 0.69; rbar = 0.38). Radial growth was negatively influenced by high temperatures at the beginning of the current growing season (r = -0.46) and by excessive rainfall at the end of the current growing season (r = -0.29), which are periods that correspond to the phenological reproductive phases of the species. Climate anomalies during this period may alter the tradeoff between growth and reproduction, in favor of the latter.

Resumo As alterações na qualidade da madeira das árvores de Eucalyptus causadas pela fertilização e disponibilidade hídrica podem influenciar as características da biomassa e do carvão vegetal. O objetivo deste trabalho foi avaliar as características da madeira e do carvão vegetal de Eucalyptus grandis sob o efeito da fertilização com potássio e sódio (controle; 4,5 kmol ha-1 de KCl e 4,5 kmol ha-1 de NaCl) e disponibilidade hídrica (100% e 63% das chuvas, com exclusão artificial por lonas em polietileno). Árvores de Eucalyptus de cada tratamento de fertilização x disponibilidade hídrica, com cinco anos de idade, foram cortadas e obtidas amostras, na altura do DAP para a caracterização energética e física da biomassa e do carvão vegetal. A aplicação da fertilização com K e Na não influenciou as características energéticas e físicas da biomassa e do carvão vegetal. A exclusão parcial da água da chuva na plantação florestal de Eucalyptus grandis promoveu alterações nas características da biomassa e do carvão vegetal, com redução do teor de cinzas, aumento da densidade da madeira e do carvão vegetal e rendimento gravimétrico do carvão vegetal.

Abstract Changes in the wood quality of Eucalyptus trees caused by fertilization and water availability may influence the characteristics of biomass and charcoal. The aim of this study was to evaluate the effects of potassium and sodium fertilization (control; 4.5 kmol ha-1 of KCl and 4.5 kmol ha-1 of NaCl) and water availability (100% and 63% rainfall with artificial exclusion) on the energetic and physical characteristics of biomass and charcoal. Eucalyptus trees of each fertilization x water availability treatments, at five years old, were cut down and the samples were taken at the DBH for the energetic and physical characterization of biomass and charcoal. The application of fertilization with K and Na did not influence the energetic and physical characteristics of biomass and charcoal. The partial exclusion of rainwater in the Eucalyptus grandis forest plantation promoted changes in the characteristics of biomass and charcoal, with reduction of ash content, and increase of wood and charcoal density and the charcoal gravimetric yield.

ABSTRACT The aim of this study was to evaluate the effects of potassium and sodium fertilization (control: 4.5kmol.ha-1 of KCl and 4.5kmol.ha-1 of NaCl), and water regimes (100% and 63% rainfall with artificial exclusion) on wood and briquette density in Eucalyptus grandis trees at 5 years, and the application of X-ray densitometry on the quality of briquettes. Tree trunk samples were obtained to determine wood density, production and briquette density by X-ray densitometry and stereometric. The artificial exclusion of rainwater promoted an increase in wood density, and the fertilization treatments versus water availability did not affect the density of briquettes. The method used to determine the briquette density influenced the average values, with an increase of 12% in the X-ray densitometry to the stereometric.

RESUMO Objetivou-se neste trabalho determinar o perfil da densidade aparente em painel aglomerado confeccionado com partículas da madeira de Acacia mangium. Utilizou-se a técnica de microdensitometria de raios X correlacionada com a densidade gravimétrica. Foram utilizados os adesivos ureia formaldeído e tanino comercial de Acacia mearnsii aplicado na forma de pó diretamente nas partículas previamente encoladas. Os painéis foram fabricados com quatro razões de compactação (1,39; 1,55; 1,73; e, 2,00) combinadas a quatro proporções de tanino em pó (0, 10, 20 e 30%), totalizando 16 tratamentos (4 painéis por tratamento). Foram determinados, analisados e comparados o perfil da densidade aparente (densidade média, densidade máxima e densidade mínima) e a densidade gravimétrica dos aglomerados produzidos. O perfil da densidade é apresentado graficamente e interpretado por análise de variância e regressão linear múltipla. Os valores de densidade aparente média, máxima e mínima observados para os painéis aglomerados obtidos pela microdensitometria de raios X variaram de 357 a 697 kg/m3, 386 a 824 kg/m3 e 334 a 634 kg/m3, respectivamente, e pelo método gravimétrico de 369 a 742 kg/m3. A técnica mostrou-se eficiente na determinação de variações nos perfis de densidade aparente ao longo da espessura dos painéis em todos os tratamentos, bem como mostrou-se eficiente na obtenção direta da densidade aparente. Estas variações poderiam ser minimizadas se o tanino utilizado fosse anteriormente hidratado em água. Houve forte correlação entre as médias das densidades obtidas pelo método do microdensitômetro de raios X e pelo método gravimétrico.

ABSTRACT This study aimed to determine the apparent density, by gravimetric technique and X-ray microdensitometry of particleboard produced with Acacia mangium wood and search existence of correlation between both methods. It was used urea formaldehyde adhesive and commercial tannin Acacia mearnsii applied in powder form directly to the previously glued particles. The panels manufactured using four compression ratios (1.39, 1.55, 1.73, and 2.00) combined four levels of powdered tannin (0, 10, 20 and 30%), making up 16 treatments (4 panels by treatment). The particleboard apparent density parameters (mean, maximum and minimum) and gravimetric density were determined, analyzed and compared. The density profile presented graphically and interpreted by analysis of variance and multiple linear regression. The apparent density, medium, maximum and minimum for particleboard obtained by microdensitometry X-ray ranged 357-697 kg/m3, 386-824 kg/m3, and 334-634 kg/m3, respectively, and gravimetric method 369-742 kg/m3. The technique was effective in determining variations in the density profile in the thickness of the particleboards in all treatments, as well as direct obtain the apparent density. These variations could be reduced if the tannin used was previously hydrated in water. Was found strong correlation (R2 = 0.99) between the mean apparent density obtained by X-ray microdensitometer and gravimetric method.

ABSTRACT The productive sustainability of eucalyptus planting is threatened when both diseases and disorders of growth occur. These interferences can have abiotic origin as environmental conditions can negatively affect the wood quality. This study has the goal of evaluating influence of different levels of physiological disorders in dendrometric variables and wood quality from seven-year-old Eucalyptus grandis x Eucalyptus urophylla hybrids intended for wood pulping production. The trees from commercial plantations in State of Maranhão, Brazil were separated into three levels of physiological disorders by means of morphologic changes. Then, they were evaluated according to dendrometric variables, anatomical characteristics, chemical properties, density of wood, and kraft pulp process. The physiological disorder levels significantly influenced all evaluated properties. Moreover, the wood from trees with higher severity of symptoms resulted in higher average values of dendrometric variables, basic density, and fibers dimensions. In addition, apparent density exhibited a different standard in the pith region with increase on radial wood profile. Trees with the least severe disorders exhibited changes in dendrometric and anatomical variables, mainly in wood volume and fibers dimensions, respectively.

ABSTRACT 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.

RESUMO A madeira de eucalipto de árvores adultas é utilizada para os mais diversos fins, entretanto, a utilização desta madeira de árvores de idade precoce é limitada. O objetivo foi caracterizar e propor utilizações para madeira de eucalipto com dois anos de idade. Seis clones de Eucalyptus grandis × Eucalyptus urophylla, com dois anos de idade, foram selecionados e suas características anatômicas, ultraestruturais, físicas e mecânicas avaliadas. A madeira do clone A apresentou fibras mais robustas e de melhor arranjo microfibrilar, resultando em melhores propriedades mecânicas e, por isto, melhor desempenho para uso estrutural. O clone F apresentou madeira com pouca variação da densidade básica no sentido radial, facilitando sua trabalhabilidade e, com o clone B, apresentou menor coeficiente de anisotropia e, por isto, a madeira é recomendada para locais com alta variação de umidade. A heterogeneidade das características da madeira dos clones avaliados corrobora a necessidade estudos por clone para uma sua melhor utilização.

ABSTRACT Eucalyptus wood from adult trees is used for several purposes; however, the wood of younger trees has limited use. This study aims to characterize and propose uses of two-year-old eucalyptus wood. Six two-year-old Eucalyptus grandis × Eucalyptus urophylla clones have been selected and their anatomical, ultrastructural, physical and mechanical wood characteristics evaluated. The wood of Clone A shows more robust fibers with better microfibril arrangement, resulting in better mechanical properties, and therefore, a better performance for structural use. Clone F showed a low variation of wood basic density in the radial direction, facilitating its machinability, and with the Clone B, showed a lower anisotropy, and therefore, the wood is recommended for locations with high variations of humidity. The heterogeneity of the wood characteristics of the evaluated clones confirms the need for further studies, to choose those most adequate to each use.

SUMMARY: An increase in drought conditions over the last century has been documented in Central Chile, a fact that could affect the Mediterranean forests, especially the northernmost Nothofagus populations from South America (Nothofagus macrocarpa). For this reason, it is key to study the climate influence on radial growth and trees establishment to design strategies of conservation and mitigation in the face of a climate change situation. In this study, 10 trees populations of N. macrocarpa were selected across natural distribution for a dendroecological analysis. The relationship between droughts and radial growth was analyzed annually, while the influence of water favorable conditions in trees establishment was evaluated in periods of 10 years. Results identified three growth patterns: (i) most degraded populations of the Coastal Mountains (young trees predominate), (ii) low-intervened forests found at a higher altitude in the Coastal Mountains and (iii) low-intervened forests of the Andes Mountains. All populations showed positive correlations with the SPEI-drought index during winter-spring, being sensitive up to 36 months after a dry period. More than 64% of the years with lowest growth are associated with historical droughts in all the chronologies, whereas trees establishment linked to humid periods was found especially in the less degraded forests (37-41% trees). These results provide an ecological vision of the climatic sensitivity of the Chilean Mediterranean forest and can contribute to the design restoration, conservation and mitigation actions in situations of global warming.

RESUMEN: Se ha documentado un aumento de las condiciones de sequía durante el último siglo en Chile central, que estaría afectando al bosque mediterráneo, especialmente a los bosques septentrionales del género Nothofagus en América (Nothofagus macrocarpa). Por esta razón resulta imprescindible estudiar la influencia del clima en el crecimiento radial y establecimiento de árboles a fin de diseñar estrategias de conservación y mitigación al cambio climático. Diez poblaciones de N. macrocarpa fueron seleccionadas para analizar la relación entre las sequías y el crecimiento radial anual y la influencia de condiciones hídricas en el establecimiento. Se identificaron tres patrones de crecimiento: (i) poblaciones más degradadas de la Cordillera de la Costa, (ii) bosques poco intervenidos y que se encuentran a una mayor altitud de la Cordillera de la Costa, y (iii) poblaciones poco intervenidas de la Cordillera de Los Andes. Todas las poblaciones presentaron correlaciones positivas con el índice de sequía SPEI (índice estandarizado de precipitación-evapotranspiración) durante invierno-primavera, siendo sensibles hasta 36 meses después de un período seco. Más del 64 % de los años con bajo crecimiento en todas las cronologías fue asociado a sequías históricas. Se observó mayor establecimiento de N. macrocarpa vinculado a períodos húmedos especialmente en los bosques poco degradados. Estos resultados entregan una visión ecológica sobre la sensibilidad climática del bosque mediterráneo de Chile y pueden contribuir en el diseño de proyectos de restauración, conservación y mitigación frente al calentamiento global.

RESUMO Expressiva área das plantações florestais de eucalipto de rápido crescimento no Brasil e em outras regiões do mundo encontra-se sob o efeito das mudanças climáticas, do estresse hídrico e da baixa fertilidade do solo, afetando o crescimento e a qualidade do lenho das árvores. O presente trabalho teve como objetivo avaliar a densidade aparente a 12% de umidade do lenho das árvores de Eucalyptus grandis com 12, 24 e 36 meses, com redução da precipitação pluviométrica e nutrição de K e Na. Os tratamentos foram definidos por dois regimes hídricos (100 e 66% das chuvas, com redução artificial com lonas de polietileno) e três tipos de nutrição: K (K - 4,5 kmol/ha), N (Na - 4,5 kmol/ha) e controle. A densidade aparente a 12% de U.R. das amostras da posição do DAP do tronco das árvores foi determinada pela densitometria de raios X e por imagens digitais do lenho. Os resultados indicaram diferença significativa da densidade aparente a 12% de U.R. das árvores de eucalipto nos tratamentos de nutrição e de disponibilidade hídrica. O perfil radial de densidade aparente mostrou maior diferença a partir do terceiro ano de idade das árvores. Pelas imagens digitais, analisou-se a variação radial da densidade aparente da madeira. Os resultados do trabalho fornecem subsídios para a adoção de práticas silviculturais nas áreas de plantações florestais com estresse hídrico e/ou afetadas pelas mudanças climáticas, bem como a substituição parcial de K por Na.

ABSTRACT Expressive area of forest plantations fast-growing of eucalyptus in Brazil and in other regions of the world is under the influence of climate change, water stress and low soil fertility, affecting the growth and the quality of the wood from the trees. This study aimed to evaluate the apparent density at 12% relative humidity of the wood of Eucalyptus grandis trees with 12, 24 and 36 months, with reduced rainfall and nutrition K and Na. The treatments were defined by two water regimes (100% and 66% of rainfall, with artificial reduction with polyethylene sheeting) and three types of nutrition: K (K - 4.5 kmol/ha), N (Na - 4.5 kmol/ha) and control. The apparent density of the samples of diameter at breast height was determined by densitometry profile from digital images of rays X. The results indicated a significant difference in nutrition treatments and water availability in relation to the density of the wood. The radial apparent density profiles showed higher differences in the wood from the third year of evaluation. Digital images of the wood obtained by X-rays allowed to analyze the variation of the apparent density of the wood. Work results may be used as subsidies for the adoption of silvicultural practices in forest plantations in areas with water stress and/or affected by climate change as well as the partial replacement of K by Na.