Acta Amazonica

Anatomical study of the seed of andiroba (Carapa guianensis) through stereo and scanning electron microscopy

2025-02-25T21:42:43.110000Z

Silva, Bruna Aparecida Da; Scussel, Vildes Maria; Tribuzi, Giustino;

ABSTRACT The points of susceptibility of seeds to deterioration are important factors, especially when stored in hot and humid tropical conditions. The seeds of andiroba (Carapa guianensis) are an important resource for Amazonian traditional communities, as the oil extracted from the seeds is widely used in popular medicine and the cosmetic industry. Yet andiroba seeds are subject to fungal spoilage, which affects the quality of the oil. We analyzed the morpho-histological characteristics of whole andiroba seeds by stereo and scanning electron microscopy to identify susceptibility points to fungi. The shell (tegument), a thick lignin-rich, protective wall structure, varied in the type and number of tissue layers, with polygonal and long shaped cells presenting pores (plasmodesmata). The junction of the three faces of the seeds at the top formed a relatively tight small cavity, the micropyle, rich in vascular bundles of helically and tracheid-shaped vessels. An interchange channel from the pod through the micropyle to the inner seed is formed between the shell and a thin brown skin towards the cotyledons, with its surface covered with adhered residues of dry placental tissue. The seed cotyledons (cross and longitudinal sections), presented different cell layers containing randomly distributed lipid droplets. We concluded that the highly irregular surface of the micropyle and channel at the seed top, which forms deep recesses and accumulates tissue residues, presents the righest risk for fungi conidia deposition and/or moisture absorption, which leads to spoilage.

Assessing the potential of tropical secondary forests in the Central Amazon for timber production

2025-02-25T21:42:43.110000Z

Modolo, Guilherme Silva; Santiago, Daniel Andrade; Dos Santos, Victor Alexandre Hardt Ferreira; Guimarães, Zilza Thayane Matos; Campos, Taynãna Freitas Leite; Reis, Aluandra Ferreira; Coelho Silva, Debora; Tomazello Filho, Mario; Schöngart, Jochen; Albiero Junior, Alci; Assis Pereira, Gabriel; Ferreira, Marciel José;

ABSTRACT Sustainable forest management is an important strategy for the conservation of tropical secondary forests. However, knowledge about their potential for timber production is scarce, especially in the Central Amazon. We performed a silvicultural diagnosis in Central Amazon secondary forests to understand their potential for forest management. The diagnosis was carried out in two secondary forest patches at advanced successional stages located 38 km north and 75 km northeast of Manaus. We quantified the commercial tree species, classified their stem quality and growth conditions (crown exposure and liana infestation), and related tree size (diameter at breast height-DBH) to growth conditions. We identified 46 commercial tree species. Goupia glabra, a very important timber species, exhibited the highest density of individuals (more than 95 individuals ha-1). Good and reasonable quality stems accounted for 87% of the commercial trees, with 45 and 42% classified as of good and reasonable quality, respectively. The species composition and stem quality of the examined secondary forests support timber production through sustainable management. Commercial trees predominantly had crowns with low light exposure (63% with a Dawkins index lower than 4) and were liana infested (62% with lianas on some part of the tree), requiring silvicultural treatments to improve growth conditions. The number of trees under suppressed growth conditions (low light and liana-infested) varied according to species and tree size, requiring specific recommendations for silvicultural treatments. These results demonstrate the potential of secondary forests for timber production and provide valuable insights for management strategies aiming at promoting sustainable management to prevent secondary forest deforestation.

Selection of chilli-pepper seedling's growth promoting rhizobacteria from an Amazonian savanna

2025-02-25T21:42:43.110000Z

Canche-Iuit, Carlos Enrique; Uchôa, Sandra Catia Pereira; Matos, Kedma Da Silva; Schurt, Daniel Augusto; Silva, Gilvan Ferreira Da; Maffei, Miguel; Silva, Deyse Cristina Oliveira Da; Severo, Eduardo Medeiros; Maia, Sonicley Da Silva; Ribeiro, Eduardo Alex Carvalho;

ABSTRACT The genus Capsicum includes economically important species important species, widely used as food and condiment. A critical stage of its production is obtaining quality seedlings, better adapted to transplanting, vegetative and productive development. The use of plant growth-promoting rhizobacteria (PGPR) in the production of high-quality vegetable seedlings can contribute to a more efficient agriculture, less dependent on crop protection products and mineral fertilizers. Therefore, the aim of this study was to select PGPR from pepper plants in the Brazilian Amazon savanna, using the quality index (QI) as a selection criterion and to evaluate their ability to produce promoters of plant growth, such as indole-3-acetic acid (IAA), phosphate solubilization (SCa-P), and biological nitrogen fixation (BNF). The experiment was conducted in Randomized Block Design (RBD) with four replications and 139 treatments, including a positive control (PC) and a negative control (NC). The ten best isolates were identified molecularly and subjected to three biochemical tests. The ten best bacteria demonstrated high growth promotion of pepper seedlings in the in vivo tests. Although not all isolates in this group demonstrated SCa-P and BNF capabilities, all of the isolates produced IAA. The bacteria isolated from the rhizosphere promoted the production of seedlings with higher QI, but the selection of bacteria based solely on the production of IAA, SCa-P, and BNF in vitro may not be enough to find the best isolates for promoting growth in pepper seedlings, as not all exhibited these mechanisms even though they improved the quality index (QI) of the seedlings.

Biomechanics evaluation of Amazonian tambaqui (Colossoma macropomum) skin puncture after preservation with glycerol 98%

2025-02-25T21:42:43.110000Z

Silva, Bárbara Rafaella Alves; Santos, Ivan Felismino Charas Dos; Mascarenhas, Adriano Reis Prazeres; Prado, Ed Johnny Da Rosa; Bergamin, Anderson Cristian; Pereira, Vinícius Lima; Moraes, Alessandra Cristina De; Pizzigatti, Dietrich; Andrade, Evelyn Rabelo;

ABSTRACT Tambaqui (Colossoma macropomum) skin represents a promising alternative for wound treatment due to its histological characteristics and mechanical properties. This study aimed to evaluate tambaqui skin preserved with glycerol 98% using mechanical puncture tests. A total of 85 tambaqui skins were randomly divided into two groups: Group 1 (G1, n = 40) - skins not subjected to glycerol preservation; Group 2 (G2, n = 45) - skins preserved in 98% glycerol. Group 2 samples were immersed in glycerol 98% and refrigerated at 5° C for 32 days. All skins underwent mechanical puncture testing to assess maximum puncture force, resistance, and deformity. Group 2 (G2) exhibited significantly higher puncture force and resistance values, and lower deformity values compared to G1. A strong correlation was found between maximum puncture force and resistance. Tambaqui (C. macropomum) skins showed greater maximum puncture strength and higher tissue resistance, with less deformity, after being preserved in glycerol 98% at a temperature of 5°C for 32 days.

Influence of fasting and refeeding cycles on growth, health and feeding costs of the Amazonian fish Colossoma macropomum

2025-02-25T21:42:43.110000Z

Gomes, Ádria Silva; Chung, Samantha; Santos, Renata Franco Dos; Gimbo, Rodrigo Yukihiro; Kojima, Juliana Tomomi; Gonçalves Junior, Lucas Pedro;

ABSTRACT Feed restriction can be used as a management strategy to increase feed efficiency through compensatory growth (a higher growth rate after a period of restricted feeding). However, there is still a lack of information on the physiological mechanisms underlying the fish responses to feed restriction. Therefore, this study aimed at investigating the cycles of fasting and refeeding on the performance, cost feeding, health and physiological mechanisms of juvenile tambaqui (Colossoma macropomum). For this purpose, feeding protocols were tested for 60 days: continuous feeding (control); two days of fasting and refeeding for two days (F2R2); two days of fasting and refeeding for three days (F2R3) and two days of fasting and refeeding for four days (F2R4), on a total of 108 two-month-old tambaqui juveniles (29.53 ± 1.31 g), distributed in 300 L boxes. Weight gain (g) was lower for the F2R2 and F2R3 treatments compared to the control. Fish subjected to the F2R4 feeding strategy showed similar growth to the group of fish continuously fed. Only the restriction protocol F2R3 resulted in a reduction in blood glucose, while cholesterol was reduced in F2R2 and F2R3. There was mobilization of hepatic glycogen in the F2R3 and F2R4 treatments, while muscle lipids were not altered. The different fasting cycles did not affect leukocyte respiratory activity, hematocrit or hemoglobin. The lowest relative feed cost values were in the F2R2 and F2R4 treatments. The F2R4 protocol reduces feed cost and maintains the ability to adjust energy metabolism without causing stress in C. macropomum.

Incidental capture and diversity of Elasmobranchii and Teleostei caught by red snapper and lobster fisheries in the Great Amazon Reef System

2025-02-25T21:42:43.110000Z

Marceniuk, Alexandre Pires; Soares, Bruno Eleres; Medeiros, Aline Paiva Morais; Caires, Rodrigo Antunes; Carvalho Filho, Alfredo; Santos, Wagner Cesar Rosa Dos; Romão Júnior, João; Costa, Wesley Assunção Da; Muniz, Mairink Ribeiro; Abreu, Valdo Sena; Gadig, Otto Bismarck Fazzano; Rosa, Ricardo De Souza; Klatau, Alex Garcia Cavalleiro De Macedo; Cintra, Israel Hidenburgo; Rotundo, Matheus Marcos;

ABSTRACT The Great Amazon Reef System is one of the least known mesophotic environments on the Atlantic coast of northern South America, threatened by oil and gas exploration projects and explored by different industrial fisheries. Here, we provide the first inventory of the cartilaginous and bony fishes captured by industrial fisheries of the red snapper and lobster in the Great Amazonian Reef System, including a list of species with ecological and conservation information, in addition to biogeographic considerations. A total of 143 species were recorded, with 17 elasmobranchs and 126 teleosts. A specimen likely representing a hybrid between Cephalopholis fulva and Cephalopholis furcifer (Serranidae) was also recorded. Community ecology descriptors were employed to explore the diversity patterns of the species captured by different fishing gears. Our results highlight the relevance of monitoring fishery activities to enhance knowledge of the biodiversity in poorly sampled areas and understanding the local impacts of human activities.

Taxonomic synopsis of Anomospermum (Menispermaceae) in the Brazilian Amazon

2025-02-25T21:42:43.110000Z

Sousa, Julio Dos Santos De; Gurgel, Ely Simone Cajueiro;

ABSTRACT Anomospermum comprises nine species and five subspecies distributed from Central to South America. This work consists of a synoptic treatment for the genus Anomospermum in the Brazilian Amazon and involved the analysis of field collections from 21 expeditions (between January 2020 and December 2022), types and botanical specimens from 32 Brazilian and foreign herbaria. In Brazil, Amazonia is the main center of diversity for the genus. The genus is represented in the Brazilian Amazon by eight species, two of them with three subspecies. Amazonas state was the most representative with seven taxa. Two new occurrences were found, one for Pará state (A. chloranthum subsp. chloranthum) and another for Amapá state (A. matogrossense). Anomospermum reticulatum subsp. reticulatum is the most common and widely distributed species of the genus in the Brazilian Amazon region. An identification key for taxa of the Brazilian Amazon, descriptions, illustrations, distribution data, and additional comments for each species are provided.

Microsternarchus javieri, a new species of weakly electric fish (Gymnotiformes: Hypopomidae, Microsternarchini) from the Negro River basin, Amazonas, Brazil

2025-02-25T21:42:43.110000Z

Escamilla Pinilla, Carolina; Cox Fernandes, Cristina; Alves-Gomes, José Antônio;

ABSTRACT Here we describe a new hypopomid species, Microsternarchus javieri n. sp., encountered in flooded savanna streams of the Branco River and in terra-firme streams in the mid- and lower portions of the Negro River basin. We compared this new species with M. bilineatus from the San Bartolo River, Venezuela, and M. brevis from the upper portion of the Negro River. We also compared this new species with two recently described species in the genus Microsternarchus, M. longicaudatus and M. schonmanni. We examined morphometrics, anatomical characters, DNA barcode distances for the COI (cytochrome C oxidase subunit I) gene, and electric organ discharge (EOD) parameters. We diagnosed M. javieri n.sp. based on variation in maximum body depth, eye diameter, caudal vertebral counts, number of anal fin rays, and the shape of the maxillae. The average intra-specific genetic distance (K2P) in M. javieri n.sp. was 0.83%, whereas the average inter-specific genetic distance to M. brevis was 12.45%, and to other hypopomids ranged from 17.21 to 21.54%. When comparing EOD waveforms of the new species with M. brevis, we found differences in repetition rate, the ratio between the first and second phase areas, and the polarity balance. The description of M. javieri n. sp. increases to five the number of species in the genus.

Unveiling the taxonomic identity of Vanilla sprucei (Orchidaceae, Vanilloideae): its phylogenetic position and a new record for Brazil

2025-02-25T21:42:43.110000Z

Krahl, Dayse Raiane Passos; Silva, João Batista Fernandes Da; Damián-Parizaca, Alexander; Flanagan, Nicola Sian; Chiron, Guy; Krahl, Amauri Herbert; Cantuária, Patrick De Castro; Pansarin, Emerson Ricardo;

ABSTRACT The pantropical Vanilla is the most species-rich genus among Vanilloideae (Orchidaceae). With 38 species, Brazil is the center of diversity for Vanilla. Several of the Brazilian taxa are considered obscure, as species boundaries are often unclear when studies are performed exclusively on dried specimens. This is the case of Vanilla sprucei Rolfe, a rare taxon with ephemeral flowers that has been referred to Brazil based on a specimen collected in the Colombian Amazonia. We present data confirming its occurrence in Brazil, together with a taxonomic evaluation of this poorly-known species including a detailed, illustrated morphological description. An epitype for V. sprucei based on Brazilian material is designated. The geographical distribution of this taxon is presented. The phylogenetic position of V. sprucei within Vanilla and its relationships with Neotropical congeners are discussed based on a phylogenetic hypothesis. Vanilla sprucei emerges at a basal node among the non-membranaceous, Neotropical Vanilla clade. The inclusion of V. sprucei in the molecular data matrix reinforces the V. trigonocarpa group as polyphyletic. For this reason, further infrageneric rearrangements will be necessary. Preliminary evaluation of the species´ conservation status according to IUCN criteria indicate a global status of Endangered, with subpopulations in Brazil assessed as Critically endangered.

Exploring local phenological and phenotypic variation of mosses (Bryophyta) in two common Amazonian habitats

2025-02-25T21:42:43.110000Z

Silva, Anna Kelly Nogueira Campos Da; Alves Júnior, Tales; Zartman, Charles E.;

ABSTRACT Species variation in relation to habitat differences may offer valuable insights into understanding population divergence and speciation itself. In central Amazonia, phenotypic and phenological variation of four bryophytes - Octoblepharum albidum, Octoblepharum pulvinatum, Leucobryum martianum and Pilosium chlorophyllum - were investigated among white-sands and terra-firme plateaus to examine whether habitat differences relate to trait variation. In three of the four species, sexual expression was significantly more restricted temporally in the drier habitat type (white-sands forest) than that observed in more mesic, terra-firme plateau forests. Contrary to global patterns of reproductive behavior for bryophytes, male expression was notably more prevalent than female expression for three of the four species. Furthermore, significant infra-specific phenotypic variation among habitat types associated with multiple measured traits (e.g., total leaf length, apex length, base width) illustrate the evolutionary potential of Amazonian bryophytes in the framework of habitat differentiation. Future priorities should focus on resource allocation dynamics and ecophysiology in a phylogenetic context to better understand the role of habitat differentiation in speciation processes among Amazonian bryophytes.

First cytogenetic characterization of Pseudoloricaria laeviuscula (Valenciennes, 1840): a monotypic genus of Loricariidae (Loricariinae)

2025-02-25T21:42:43.110000Z

Alegria Serra, Ana Júlia; Soares, Simone Cardoso; Marajó, Leandro; Feldberg, Eliana; Alves Gomes, José Antônio;

ABSTRACT This study presents the first cytogenetic characterization of Pseudoloricaria laeviuscula, a species widely distributed in the Amazon and Tocantins-Araguaia basins. Individuals collected from the Negro River, Amazonas, Brazil, exhibited a diploid chromosome number (2n) of 54, with a karyotypic formula of 14m + 10sm + 4st + 26a and a fundamental number of 82. The nucleolus organizer region (NOR) was interstitially located on a pair of subtelocentric chromosomes, confirmed via FISH using the 18S rDNA probe. Constitutive heterochromatin is preferentially located in centromeric regions, and 5S rDNA was mapped pericentromerically in a single acrocentric pair. The telomeric probe exclusively mapped the terminal regions of the chromosomes. The cytogenetic study revealed plesiomorphic characteristics of the Loricariidae family, such as the diploid number, NOR location and heterochromatin distribution. However, the localization of 18S and 5S rDNA sites on distinct chromosomes represents a derived feature. Comparative cytogenetic analysis of species in the Loricariichthys group indicates the occurrence of non-Robertsonian chromosomal rearrangements. Thus, the data from the present study expand our knowledge of the genus Pseudoloricaria and can serve as cytotaxonomic markers for a better understanding of the Loricariichthys group and its relationships within the subfamily Loricariinae.

How to remove the brain of Amazonian manatee (Trichechus inunguis) calves preserving the skull for morphological analysis

2025-02-25T21:42:43.110000Z

Avelino-De-Souza, Kamilla; Valdevino, Gisele De Castro Maciel; Melo-Santos, Gabriel; Mota, Bruno; Da Silva, Vera Maria Ferreira;

ABSTRACT Although there are several studies on the skull of Amazonian manatees (Trichechus inunguis) to better understand the anatomy, physiology, and behavior of these animals, the analysis of the brain has been often neglected. Typically, in osteological studies, the brain is discarded to preserve the integrity of the skull. One of the main reasons for this neglect of the brain is the lack of adequate dissection protocols to allow the extraction of the intact brain while preserving the integrity of the skull. In this study, we present a simple step-by-step protocol for a comprehensive procedure of brain extraction and fixation in manatee calves while ensuring the preservation of the skull structure to the best possible extent for further studies. The protocol is based on an incision at the posterior part of the skull, extending laterally toward the parietal bone until reaching the frontal bone, followed by removing the upper portion of the skullcap to extract the brain. After the procedure, the removed skull portion can be reconstituted to preserve the entire skull structure. The protocol also offers adaptations to simplify the methodology according to the reality of places with little laboratory structure, allowing the preservation of rare tissues with limited resources and/or in areas of difficult access. Our proposed methodology enables maximum utilization of the collected animal, which not only aligns with ethical and practical considerations, but also makes material available for a detailed description of the manatee brain, and a better understanding of the neuroanatomy of aquatic mammals in general.

Avifauna of a white-sand forest in the Colombian Amazon

2025-02-25T21:42:43.110000Z

Colorado Z., Gabriel J.; Valencia-C, Giovany;

ABSTRACT White-sand forests are unique ecosystems with high levels of biological specificity. Despite their uniqueness, these ecosystems have significant knowledge gaps in Colombia regarding the associated vertebrate communities, particularly birds. Between February and March 2015, richness and composition of birds in a white-sand forest in the southern-most region of the Colombian Amazon were evaluated using mist nets and censuses. 38 bird species were detected, less than half of the number recorded in the surrounding terra-firme forest (81 species). In addition, the white-sand forest exhibited a high degree of specificity, as indicated by a Jaccard index of 0.25 when compared to the terra-firme forest. Although this ecosystem currently faces low conservation threats in this region of Colombia, its biological fragility and specificity, and the absence of a legal protection status, make it a vulnerable ecosystem.

First record of the predaceous midge Schizonyxhelea zoologica Huerta & Grogan, 2017 (Diptera: Ceratopogonidae) in South America, with description of the female

2025-02-25T21:42:43.110000Z

Da-Silva, Irene M.; Cazorla, Carla G.; Desidério, Gleison R.; Ferreira-Keppler, Ruth L.;

ABSTRACT Schizonyxhelea zoologica Huerta & Grogan, 2017, previously known from North America (Mexico), is reported for the first time in South America (Brazil). Additionally, the female of this species is described and illustrated for the first time. The females were collected in association with males in a preserved forest and an urban forest fragment, located in Amazonas State, Brazil. Schizonyxhelea zoologica is the fifth species of the genus recorded in Brazil, and the first species of the genus documented in Amazonas. Finally, a brief commentary on the environment in which the specimens were found, as well as their biogeographical importance, is provided.

Contributing to the knowledge of the distribution of the world’s smallest angiosperms in the Amazon: first record of Lemna minuta Kunth (Araceae) in the state of Pará, Brazil

2025-02-25T21:42:43.110000Z

Soares, Witalo Cleidson Rodrigues; Comassetto, Thaisa Pegoraro; Fidanza, Karina;

ABSTRACT Lemnoideae is a yet little known taxon in Brazil in taxonomic and distributive terms, given the few records for the country, especially in the Amazon region. Here, we present the first record of Lemna minuta Kunth for the state of Pará, providing a description of the species, its occurrence in Brazilian territory, and additional comments. This contributes to expanding the knowledge of the species’ distribution in the Amazon.

Microbiological and antimicrobial evaluation of drinking water in floating houses of the Brazilian Amazon

2025-02-25T21:42:43.110000Z

Chamy, Michel Nasser Corrêa Lima; Secoli, Silvia Regina; Soares, Fernando Mauro Pereira; Poveda, Vanessa De Brito;

ABSTRACT Limited access to safe water and basic sanitation contributes to morbidity and mortality caused by waterborne diseases, and reinforces social inequalities. The aim of this study was to evaluate the microbiological quality of water consumed by residents of floating houses and the antimicrobial susceptibility profile of the isolates in the low and increasing flow regime in the Amazon River basin. The samples consisted of drinking water from floating domestic units located on the edges of cities in the Amazon region, Amazonas state, Brazil. Sampling occurred during the low (LWL) and raising river-water level (RWL) periods. Water samples were analyzed using the filtering membrane method. The antimicrobial susceptibility test was performed using the disk-diffusion method. The source of water for consumption was predominantly tubular/artesian wells (75.0% LWL; 72.7% RWL); the main storage form was in PET (polyethylene terephthalate) bottles or buckets (90.9%) and the majority of the residents (63.6%) did not treat the water before consumption. Most water samples were contaminated with Escherichia coli during both the LWL (86.3%) and RWL periods (82.5%). Enterococcus spp., Vibrio spp. and Salmonella spp. were identified in association with water contamination by E. coli. Salmonella spp. exhibited the highest resistance rate among the bacteria subjected to antimicrobial susceptibility testing, especially during the LWL period; 100% showed resistance to ampicillin and cefazolin, 68% were resistant to tobramycin and 64% to gentamicin. Therefore, raising public awareness about the consumption of safe water, through dissemination of proper water storage and disinfection procedures could help minimize contamination and reduce waterborne diseases.

Respiratory infection in indigenous population of the Amazon region, Brazil

2025-02-25T21:42:43.110000Z

Silva, Larissa Mendes Da; Novais Júnior, Linério Ribeiro De; Pereira, Pablo Michel Barcelos; Ramos, Suelen De Souza; Meneguzzo, Vicente; Daros, Guilherme Cabreira; Silva, Marina Goulart Da; Portela, Williams Ferreira; Goldim, Mariana Pereira De Souza; Iser, Betine Pinto Moehlecke; Bitencourt, Rafael Mariano De;

ABSTRACT Respiratory infections are considered the leading cause of mortality among communicable diseases in indigenous populations, becoming a public health issue. This case study was conducted in Amaturá municipality (Amazonas, Brazil) indigenous communities. On total 2.728 medical records for respiratory infections from the Alto Rio Solimões Special Indigenous Health District (DSEI) were analized. Of these, 52.7% were females, and 76.6% were under 18 years old. Acute nasopharyngitis was the most frequent diagnosis (91.5% of cases). The age group 1 to 4 years showed a higher frequency of some conditions. Females showed a significant likelihood ratio (LR) with unspecified acute tonsillitis, and males with acute laryngopharyngitis. The specific analysis of the village revealed LR for acute bronchitis caused by rhinovirus in Bom Pastor, and acute bronchitis caused by respiratory syncytial virus and Streptococcus in Nova Itália. This study highlights the high frequency of upper respiratory infections in the largest indigenous district of the Brazilian Amazon, especially affecting children aged 1 to 4 years. Though often self-limiting, these infections can lead to more severe lower respiratory issues. The findings stress the need for effective preventive measures, better healthcare access, and environmental policies to reduce the health impacts of pollution. The study also calls for more research with better representation of indigenous diversity and emphasizes the importance of strengthening health surveillance systems and social participation in healthcare planning.

Stiffness of wood from two hyperdominant species in Central Amazon evaluated by different nondestructive methodologies

2025-02-25T21:42:43.110000Z

Nascimento, Cristiano Souza Do; Araújo, Roberto Daniel De; Nascimento, Claudete Catanhede Do; Higuchi, Adma Magni Darwich; Santos, Joaquim Dos; Higuchi, Niro;

ABSTRACT This study evaluated nondestructive testing (NDT) to estimate the stiffness of Protium puncticulatum (Breu-vermelho) and Micrandropsis scleroxylon (Piãozinho) wood. A total of 100 test samples (20×20×300 mm) were manufactured from the wood of three trees of each species, with the final dimension aligned longitudinally. NIR spectroscopy, a stress wave timer and a regression equation were used to estimate stiffness, with the traditional methodology used as a standard. The destructive methodology resulted in average stiffness values of 9890 MPa for P. puncticulatum wood and 15002 MPa for M. scleroxylon. Pearson correlation results indicate that the regression equation (r=0.83; 0.72) and NIR spectroscopy (r=0.79) presented the strongest correlations with the standard method for predicting stiffness. When nondestructive testing was evaluated without distinguishing between species, statistical analysis revealed no significant differences between methods. The evaluated methods estimated stiffness satisfactorily, albeit with variations. NDT 1 overestimated stiffness across species, NDT 2 provided better distribution, and NDT 3 estimated stiffness well for M. scleroxylon but underestimated stiffness when applied to multiple species. These findings demonstrate that NDT methods offer an alternative to traditional destructive testing for wood characterization, but highlights the importance of selecting an appropriate nondestructive method for each wood species.

ERRATUM

2025-02-25T21:42:43.110000Z