ABSTRACT Background: Multiple challenges are faced by industry and certification agencies when commercializing tropical species. Anatomical similarities of tropical hardwoods impair identification. Deep learning models can facilitate microscopic identification of wood by using sophisticated techniques such as deep convolutional networks (DCNN). Our objective was to microscopically identify 23 commercially available Brazilian wood species using a custom DCNN model. Results: Photographs from microscopic slides of each wood species were processed, and the final data set contained 2,448 images. We applied stratified k-fold cross-validation technique during training to increase model’s robustness and trustworthiness. Thus, the dataset was divided into approximately 80% training (1,958 images) and 20% validation (490 images) for each fold. A series of augmentations were performed only on training data to include variations in rotation, zoom, and perspective. Image augmentation was performed on-the-fly. The network consisted of convolutions, max pooling, global average pooling, and fully connected layers. We tested the performance of the DCNN against accuracy, precision, recall, and F1-score on the validation set for each fold. Conclusion: The custom machine learned model accuracy was higher than 0.90. The model’s worst performance was identified in distinguishing between Toona ciliate and Khaya ivorensis, which was due more to wood variability than to a machine learning deficiency. Future studies should focus on integration, verification/monitoring, and updating of current models for end user manipulation, trust, ethics, and security.

Abstract: The aim of the research was to evaluate the effect of the attack Leptocybe invasa in dendrometric variables and wood properties of two clones of eucalyptus (Eucalyptus urophylla and Eucalyptus tereticornis), grown in the municipalities of Imperatriz (state of Maranhão) and Darcinopolis (state of Tocantins), Brazil, for Kraft pulping. Data were collected 10 trees for each clone, the 3-year-old attacked by L. invasa. The diagnosed was based on formation of large guts all over the glass, and emergency hole (closing the loop). The results were confirmed by the variation of the characteristics of species assessed relative to their total height, diameter, volume of bark, vessel frequency, fiber size, radial density profile vessel frequency, fiber size, radial density profile, and ash content. Host trees obtained alterations in dendrometric variables, content of pentosans and wood ashes for both genetic materials, not being observed variations in specific gravity, and size of vessels and fibers, as well as the contents of lignin and wood extractives.

Resumen: El objetivo de la investigación fue evaluar el efecto del ataque de Leptocybe invasa en las propiedades dendrométricas de la madera de dos clones de eucalipto (Eucalyptus urophylla y Eucalyptus tereticornis), cultivados en los municipios de Imperatriz (Estado do Maranhão) y Darcinópolis (Estado de Tocantins), Brasil, destinados a la producción de pulpa kraft. Se analizaron 10 árboles de 3 años de edad atacados por Leptocybe invasa, para cada clon. El diagnóstico fue basado en la formación de grandes agallas en la copa, y con orificio de emergencia (cerrando el ciclo). Los resultados fueron constatados por la variación de las características de las especies evaluadas con relación a su altura total, diámetro, volumen de corteza, frecuencia de vasos, longitud de fibras, perfil radial de densidad y contenido de cenizas. Los árboles hospederos presentaron alteraciones en las variables dendrométricas, contenido de pentosanos y cenizas en la madera para ambos materiales genéticos, no siendo observadas variaciones en la densidad básica, dimensión de vasos y fibras, así como en los contenidos de lignina y extractivos de la madera.

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.