Wood Basic Density Research Articles

Non-destructive modeling using a drilling resistance tool to predict wood basic density of standing trees in a eucalypts plantation in North Sumatra, Indonesia

Abstract. Singh KP, Siregar IZ, Abad JIM, Karlinasari L. 2022. Non-destructive modeling using a drilling resistance tool to predict wood basic density of standing trees in a eucalypts plantation in North Sumatra, Indonesia. Biodiversitas 23: 6218-6226. Eucalypts are globally selected as the main tree species for pulp and paper industries owing to their good potential growth and wood traits. Wood basic density, which is related to wood biomass yield, is one of the most important wood traits for pulp production and has become a focus in the tree improvement program. Evaluation of this trait in the field is needed to efficiently develop tree improvement programs. The aims of this study were to determine the distribution of basic density in the vertical direction of standing trees, including Eucalyptus grandis, Eucalyptus urophylla, and E. grandis × E. urophylla hybrid (commonly called “urograndis”), and to develop a model for predicting wood basic density using micro-drilling resistance tools of ResistographÒ. The results showed that basic density traits varied within individual trees and within and between species. Average whole tree basic wood densities of 379.9 kg/m3, 400.5 kg/m3, and 440.6 kg/m3 were found for E. grandis, hybrid urograndis, and E. urophylla at 44 months old, respectively. The model developed had a good correlation for predicting wood basic density at 1.3 m height and whole tree basic density, with the R2 for model calibration ranging from 0.52 to 0.76 for 1.3 m wood basic density prediction and from 0.62 to 0.79 for whole tree wood basic density. This study found that the three species of eucalyptus could be used to create a combined model for predicting wood basic density that could be used for each individual species. The model for single and multiple species had a good validation with R2 from 0.51 to 0.72.

Effect of stem rot on wood basic density, carbon, and nitrogen content of living deciduous trees in hemiboreal forests

While numerous studies have focused on analyzing various aspects of the carbon (C) budget in forests, there appears to be a lack of comprehensive assessments specifically addressing the impact of stem rot on the C budget of broadleaf tree species, especially in old-growth forests where stem rot is prevalent. One of the main challenges in accurately quantifying C losses caused by stem rot is the lack of precise data on the basic density and C content of decayed wood, which are crucial for converting decayed wood volume into biomass and C stocks. Using linear mixed-effects models, we examine the variability of wood basic density, C content, and nitrogen (N) content. Discolored and decomposed wood was collected from the stems of 136 living deciduous trees common in hemiboreal forests in Latvia. Our research indicates a noticeable reduction in the wood basic density, coupled with an increase in the N content within the stem wood throughout the decomposition process in birch (Betula spp.), European aspen (Populus tremula L.), grey alder (Alnus incana (L.) Moench), and common alder (Alnus glutinosa (L.) Gaertn.). While aspen wood showed a decreasing trend in C content as decay progressed, a pairwise comparison test revealed no significant differences in C content between discolored and decomposed wood for the studied species, unlike the findings for basic density and N content. This study emphasizes the need to account for stem rot in old-growth forest carbon budgets, especially in broadleaf species, and calls for more research on stem rot-induced carbon losses.

DENSIDADE BÁSICA DA MADEIRA, DIMENSÕES DAS FIBRAS E COMPOSIÇÃO QUÍMICA DA MADEIRA DE QUATRO ESPÉCIES DE Eucalyptus PLANTADAS NO SUL DO BRASIL

ABSTRACT In the Brazilian planted forest sector, most of the species used are from the genus Eucalyptus. Even though Southern Brazil has a suitable climate for species of the genus Pinus, the planting of frost-resistant Eucalyptus species has been increasing annually. The objective of this study was to evaluate the basic density, fiber dimensions, and chemical composition of Eucalyptus benthamii, Eucalyptus dunnii, Eucalyptus saligna, and Eucalyptus cloeziana woods. The trees used were from a six-year-old experimental plantation located in Canoinhas, state of Santa Catarina. For each species, three trees were selected, and discs were removed from each tree at 0%, 25%, 50%, 75%, and 100% of the commercial stem height. To evaluate the quality of the wood, the basic wood density, fiber dimensions, and chemical composition of the wood were determined by comparing the values between species and between the heights in the stem. The highest basic density was that of the wood of E. cloeziana; this species also had the greatest length and width of fibers. E. dunnii had the lowest levels of lignin and the highest levels of holocellulose. The highest lignin content was found in the wood of E. benthamii, E. saligna, and E. cloeziana. The relationship between wood properties and stem height was not relevant. The results highlight the tendency for higher extractives to be found at taller heights (100%), and holocellulose and lignin content are similar at all heights.

Estimation of the basic density of wood in three tropical species in Chiapas, Mexico

It has now been shown that the basic density of wood is related to tree growth and carbon storage capacity, it also providesinformation such as the resistance, durability and quality of the wood, with this, the efficient use of wood in tropical species isdetermined. The objective of this research was to estimate the basic density of wood in three tropical species (Tectona grandis L. f.,Gmelina arborea Roxb. and Cedrela odorata L.). To estimate the basic density of the species, the empirical method was used,which consists of extracting a core from the tree using a pressler drill, at a breast height (1.30 m), once the 20 cores per specieshave been obtained, the small samples are dehydrated in a drying oven until a constant temperature is obtained, through this thebasic density per species was obtained. Once the density data was obtained they were subjected to an analysis of variance and latera Tukey test was applied. The statistical analysis indicates that, if there are significant differences between the species, where thehighest basic density occurred in Tectona grandis L. f. with 0.59 g/cm³, followed by Gmelina arborea Roxb. 0.44 g/cm³ and finallyCedrela odorata L. with 0.37 g/cm³, these values according to the wood classification indicate that teak and melina have mediumwood and cedar has low wood

Energy Properties of 22 Timber Species from Oaxaca, Mexico

The potential use of forest species as fuels depends on their energy quality. However, in rural communities in developing countries, fuelwood is still an energy source without any technical study evaluating its energetic characteristics. Therefore, this study aimed to analyze the energetic characteristics of 22 forest species from four communities in the state of Oaxaca, Mexico. The basic wood density, proximal analysis, and high heating value were evaluated. As a result of the analysis, the fuel number (FN) is proposed as a measure of the energy quality of biomass fuels in the form of firewood. FN considers the basic wood density, the fixed carbon, and the high heating value of each species. Wood basic density ranged from 0.472 g·cm-1 for Pinus pseudostrobus to 0.814 g·cm-3 for Dodonaea viscosa, fixed carbon ranged from 4.74% to 21.27% for Liquidambar styraciflua and Quercus rugosa, respectively, and high heating value from 18.33 MJ·kg-1 to 22.07 MJ·kg-1 for Liquidambar styraciflua and Pinus leiophylla, respectively. Classifying wood according to FN, in decreasing order, Quercus rugosa stands out as the best wood (66.97%), followed by Liquidambar styraciflua (39.52%). Regarding the fuel value index, the nine pine species showed the highest values (27.32 to 77.76). The FN provides a measure of the quality of biomass fuels in the form of firewood, and can be evaluated by easily measured variables.

Modelling the influence of radiata pine log variables on structural lumber production

We run logit models to explain the variability of Pinus radiata structural lumber in 71 second and third unpruned logs. The response variable was the proportion of lumber with a static modulus of elasticity greater or equal than 8000 MPa, pMSG8+, and the explanatory variables were log volume, branch index, largest branch, log internode index, wood basic density, and acoustic velocity. The average pMSG8+ volume was 44,30 % and 36,18 % in the second and third log respectively. Ten models were selected based on meeting statistical assumptions, their goodness of fit, and the statistical significance of their parameters. The best models (R2 - adj. > 0,75) included acoustic velocity (AV) as explanatory variable, which explained 56,25 % of the variability of pMSG8+. Models without AV presented goodness of fit ranging from 0,60 to 0,75 (R2 - adj.), and variables with the highest weight to explain the variability of pMSG8+ were volume, followed by wood basic density, branch index, and largest branch. It is possible to model pMSG8+ from log variables even when acoustic velocity is not available; however, this requires wood basic density models calibrated for the Pinus radiata growing zone.

NIR-based models for estimating selected physical and chemical wood properties from fast-growing plantations

As a faster, reliable, and low cost technique, applicable to large samplings, near infrared (NIR) spectroscopy technology has been widely applied for high-throughput phenotyping in forest breeding programmes. The aim of this study was to develop multivariate models for estimating the chemical and physical properties of juvenile wood based on NIR signatures of milled wood. Moreover, two approaches, namely, external validation by clone and by age, were tested to validate the model for estimating extractive content. NIR spectra of wood specimens taken from three clones of Eucalyptus urophylla (one to six years old) grown in southern Brazil were used to calibrate and validate models for predicting the wood basic density, total extractives, ash content, holocellulose content, syringyl to guaiacyl ratio (S/G) and elementary components of the wood. PLS-R models were validated by an independent set of wood specimens and presented promising statistics for the estimating wood density (R2p = 0.768), extractives (R2p = 0.912), ash (R2p = 0.936) and carbon (R2p = 0.697) contents from NIR signatures measured in the milled wood of young trees. Furthermore, NIR models for estimating the extractive content of wood were validated using the clones or ages left out of the training sets. Most models presented satisfactory statistics (R2 > 90%) and could be applied to routine laboratory analyses or to select potential trees in Eucalyptus breeding programmes.

WOOD DENSITY AND ANNUAL RING WIDTH OF PEDUNCULATE OAK FROM STANDS GROWN ON FORMER AGRICULTURAL LAND

The main aim of this study was to determine differences in basic density and average annual ring width of pendulate oak wood collected from trees grown on former agricultural land and on forestland, using a dimensional method. The experiment was carried out in thewestern part of Poland, near to Poznan, which is in the central part of the European range of pedunculate oak. In our study the average basic density was 0.528 g.cm-3, and the value for former agricultural land was lower by 0.026 g.cm-3 than that for forest land. Differences in basic density values between these two land types were statistically significant. The average annual ring width in samples collected from forest land in our study was 2.48 mm, samples from former agricultural land were characterized by wider average annual rings. The results suggest that there are significant differences in quality of wood from former agricultural land and from forest. However, from view of wood quality and applications the difference is not important.

CREATION OF DECORATIVE FORMS OF SCOTS PINE FOR THE GREENING OF URBANIZED ENVIRONMENT

The features of creating decorative forms from Scots pine trees are considered. It has been established that, as a result of mechanical damage (death of an apical bud or an apical shoot) and subsequent regeneration processes in pine trunks, two main directions of post-traumatic deformations of young pine trunks stand out - violation of monopodial branching and occurrence of multi-stemming. In the case of the death of an apical bud or apical shoot, in early spring, the growth of shoots from whorl buds is activated and their vertical reorientation occurs. After a short period of relative multi-stemming, one of the shoots from whorl buds takes the place of the central shoot. Formation of multi-stemming occurs in the case of the death of an apical shoot, mainly in late spring-summer period. There is also an increased growth of shoots from whorl buds and their vertical reorientation. All shoots formed from whorl buds retain their vertical orientation in the future with subsequent formation of several separate stems. It is shown that the processes of mechanical damage-regeneration are also reflected in the condition of trunk wood in the places of damage. In trunk areas where mechanical damage and subsequent regeneration took place, a noticeable increase in the basic density of wood is observed - by 15-20 % in case of shoot replacement and by 25-45 % in case of multi-stemming. The content of late wood also increases - by 10-30 % in case of shoot replacement and by 15-35 % in case of multi-stemming. It is recommended, to create decorative forms, to select pine trees no older than 8-10 years old, with an average growth rate in height. Decorative forms of Scots pine require annual adjustments.

Specific cutting energy of Eucalyptus wood with different densities

The aim of the study was to evaluate how the specific cutting energy is influenced by the variation of the wood basic density in Eucalyptus spp. clones. Five clones, 10 years old, were used in the study: three hybrids of Eucalyptus grandis x Eucalyptus urophylla, one of Eucalyptus grandis and one of Eucalyptus urophylla. From each clone, five trees were cut down and divided into 2.0 m long logs. In two axial regions of the trunk (from 2.5 to 4.5 m and from 4.5 m to 6.5 m) the logs were cut into boards and reduced to specimens with dimensions of 660 x 110 x 21 mm. The basic density was determined by the hydrostatic method in two opposite wedges obtained from discs removed at 2.5, 4.5 and 6.5 m from the total height of the tree. To analyze the specific cutting energy, 10 specimens were selected for each axial region and clone. A frequency inverter was used to monitor the cutting process. Analysis of variance was applied to evaluate the specific cutting energy and the wood basic density. The results obtained appointed a significant difference between the woods of the clones for basic density and specific cutting energy. For the wood in the different axial regions, only the specific cutting energy was significant. Clone 1 required less specific cutting energy, as it was influenced by the lower basic density. In the 2.5 to 4.5 m axial region, a higher specific cutting energy was observed even with lower basic density.

Energy potential of wood from clones of Eucalyptus and Corymbia in different spacings

This study aimed to determine the influence of spacing and different genetic materials of Eucalyptus and Corymbia on wood production for energy purposes. At 24 months, two Eucalyptus clones (C1 and C2) and two Corymbia clones (C3 and C4) implanted in three different spacings (3.0 × 3.0, 3.0 × 1.5, and 3.0 × 1.0 m) were evaluated, totaling 12 treatments. In each treatment, 4 trees were selected, and 5 disks were removed from each tree, which were used to determine the basic density, the higher calorific value and to quantify the elemental carbon in the wood. Based on these characteristics, it was possible to estimate the dry mass, the carbon mass, and the amount of energy per hectare. It was observed that there was an effect of spacing, clone and interaction for the basic density of wood, being observed in clone C3 (C. citriodora × C. torelliana) the highest values of this property. As for the higher calorific value and the carbon content, no significant effect was found. It was also verified that the production of dry mass, carbon mass, and the amount of energy available per hectare increased with the densification of the spacings for all clones studied. The highest values of the amount of energy per hectare, in the different spacings, were attributed to clones C2 and C3 (3.0 × 3.0 m), clone C3 (3.0 × 1.5 m), and clones C1 and C3 (3.0 × 1.0 m). The C3 clone (Corymbia hybrid) can be a good alternative for energy use, due to its wood quality and productivity similar, or even superior, to Eucalyptus clones already used for this purpose.

Variation in Growth, Wood Basic Density and Fiber Characters in Selected Clones of Acacia auriculiformis A. Cunn. Ex benth

The study aimed to screen and shortlist superior Acacia auriculiformis clones for desirable growth and wood properties. Twenty clones stem volume, wood basic density and fibre characters were studied at age of four. Significant variations were recorded in tree volume and wood properties among the clones, the stem volume of the clones was ranging from 0.022 to 0.073 m3 and the maximum tree volume was noticed in clones IFGTBAA 7 and followed by IFGTBAA 27 and 18, the studied clones average stem volume was 0.039 m3. The average wood basic density of the clones was 469 kg/m3 and this trait was ranging from 406 to 509 kg/m3. The screened A. auriculiormis clones average fibre length was ranging from 785.4 µm to 1140.6 µm and a maximum fibre length above 1000 µm was recorded in clones IFGTBAA 18, 23, 26 and 62. The average Runkel Ratio of all the clones was 0.91 and it was ranging from 0.7 to 1.1. There was no significant positive correlation noticed between growth, wood basic density and fibre properties except stem volume and fibre lumen diameter. Hence, it was decided to select superior clones, IFGTB 7,18,20,23 and 27 based on combined traits of Stem Volume, Wood Basic Density and Fibre Length to establish large scale commercial pulp wood plantations and clones which were having higher density and fibre properties had scope to utilize as parents in A. auriculiformis improvement programme to enhance tree volume and wood quality.

Almacenamiento de carbono en etapas de crecimiento de Pinus patula Schiede ex Schltdl. & Cham. en la Sierra Alta Hidalguense

Introduction: Forests provide environmental goods and services associated with the forest ecosystem, such as carbon sequestration, which has market potential to contribute to profitability and sustainability of forestry activities. Objective: To estimate biomass and aboveground carbon during the development stages of a Pinus patula Schiede ex Schltdl. & Cham. forest, cultivated in the ejido Atopixco, Zacualtipán, Hidalgo, to know the potential of the species for climate change mitigation. Materials and methods: Aerial biomass was estimated by non-destructive method, using direct measurement of height and diameter at breast height. The volume estimated for the trees sampled, at each stage of development, was multiplied by the basic wood density and the carbon coefficient of 50 % was used. Results and discussion: The average biomass of mature trees was 294.8 kg. Estimates of aboveground carbon at the developmental stages of P. patula were as follows: brinzal (0.94 Mg C·ha-1), monte bravo (3.73 Mg C·ha-1), vardascal (5.05 Mg C·ha-1), latizal (18.18 Mg C·ha-1) and fustal (81.40 Mg C·ha-1). The non-destructive method allowed reliable estimates of carbon content of this species. Conclusion: Carbon storage quantification by stages of development of P. patula is useful marketing strategies of environmental services for carbon sequestration, which has imminent market potential to mitigate the impacts of climate change.

Insights about wood density in Atlantic Forest ecosystems: spatial variability and alternative measurement

Basic wood density (BWD) is a functional characteristic important to quantify carbon storage and is related to tree growth and its survival. We investigated BWD variability among tree species, populations, and forest types across the Atlantic Forest biome in Rio de Janeiro state, Brazil. We sampled and measured 576 trees of 83 species in 28 natural ecosystems in the Dense Ombrophilous Forest, Seasonal Semi-deciduous Forest, and the Restinga Forest. Stem wood from two different heights at each tree was acquired using a drill borer; discs were removed from branches in 20% of the height from 39 trees. BWD means increased from 0.42 for the most humid ecosystem to 0.675 g⋅cm−3 from the driest ecosystem. We identified changes in the wood as a result of climatic variables particular to different typologies, such as increased wood density in areas with lower precipitation and higher temperatures, were also observed within species, but with little difference in means. We identified three groups of species according to their BWD, different in mean height and diameter. The branches can be used to estimate tree wood density.

Clarifying the carbonization temperature effects on the production and apparent density of charcoal derived from Amazonia wood wastes

Controlling the carbonization process in brick kilns based on temperature and selecting raw material to reduce heterogeneity are key challenges in producing high-quality charcoal from Amazonia wood wastes. The study's main objective was to investigate how the final carbonization temperature and different Amazonian wood species affect the carbonization efficiency and the charcoal apparent density (CAD). After determining wood basic density (WBD), the wastes underwent carbonization on a laboratory scale at four final temperatures (400, 500, 600, and 700 °C). The gravimetric yield in charcoal (GYC), the specific consumption of firewood (SCF), and the CAD were evaluated. The CAD ranged from 0.248 (T. guianensis) to 0.656 g cm−3 (Licania sp.) and showed a positive correlation with WBD at all temperatures (400 °C - r = 0.954, 500 °C - r = 0.944, 600 °C - r = 0.930, and 700 °C - r = 0.927). Wastes from the species P. suaveolens and D. excelsa showed the highest mean values of GYC regardless of the carbonization temperature. The increase in the final carbonization temperature from 400° to 700°C reduced the GYC and increased the SCF and CAD. The species T. guianensis (25.6%), Manilkara sp. (25.4%), and D. excelsa (24.7%) showed more significant reductions in GYC from 400° to 700°C. Thus, temperatures below 500 °C are recommended for charcoal production from Amazonia wood wastes to provide better carbonization performance. In our study, charcoals from Licania sp., D. excelsa, and Manilkara sp. were the densest and, therefore, most suitable for the steel industry.

Fiber quality and wood basic density of species of the Savannah for productive purposes

The objective of this study was to qualify the wood of the species Astronium fraxinifolium, Enterolobium gummiferum, Eriotheca pentaphylla, and Plathymenia reticulata of the Brazilian Cerrado for forestry productive purposes based on the classification of their wood basic density and fiber quality indices. Discs were removed at a height of 1.3 m from the ground, and opposing wedges were obtained. The analyzed parameters were: wood basic density, fiber dimension, and fiber quality indices. The wood basic density was negatively correlated with fiber length and thickness. E. pentaphylla presented low basic density, long fiber length, and greater fiber wall thickness. On the other hand, A. fraxinifolium, E. gummiferum, and P. reticulata woods presented medium/high basic density, short fiber length, and quality indices that foster them for energy purposes, paper production, and use in floors and civil construction.

Xylem Transcriptome Analysis in Contrasting Wood Phenotypes of Eucalyptus urophylla × tereticornis Hybrids

An investigation of the effects of two important post-transcriptional regulatory mechanisms, gene transcription and alternative splicing (AS), on the wood formation of Eucalyptusurophylla × tereticornis, an economic tree species widely planted in southern China, was carried out. We performed RNA-seq on E. urophylla × tereticornis hybrids with highly contrasting wood basic density (BD), cellulose content (CC), hemicellulose content (HC), and lignin content (LC). Signals of strong differentially expressed genes (DEGs) and differentially spliced genes (DSGs) were detected in all four groups of wood properties, suggesting that gene transcription and selective splicing may have important regulatory roles in wood properties. We found that there was little overlap between DEGs and DSGs in groups of the same trait. Furthermore, the key DEGs and DSGs that were detected simultaneously in the four groups tended to be enriched in different Gene Ontology terms, Kyoto Encyclopedia of Genes and Genomes pathways, and transcription factors. These results implied that regulation of gene transcription and AS is controlled by independent regulatory systems in wood formation. Lastly, we detected transcript levels of known wood biosynthetic genes and found that 79 genes encoding mainly enzymes or proteins such as UGT, LAC, CAD, and CESA may be involved in the positive or negative regulation of wood properties. This study reveals potential molecular mechanisms that may regulate wood formation and will contribute to the genetic improvement of Eucalyptus.

Simulated annealing in feature selection approach for modeling aboveground carbon stock at the transition between Brazilian Savanna and Atlantic Forest biomes

Forest ecosystems are important in the carbon storage process. Thus, the objective was to investigate the effectiveness of the Simulated Annealing meta-heuristic analysis for selecting variables to maximize the accuracy of the aboveground carbon prediction at the tree level. We used data from uneven-aged forests located in the Rio Grande Basin - Minas Gerais, Brazil, where 227 trees had their carbon stock measured. The classic Spurr linear model, stepwise linear regression and pan-tropical coverage, Random Forest (RF), and the hybrid SARF method (Simulated Annealing and Random Forest) were used to estimate the carbon stock from the selection of variables for the different compartments of the tree (total, stem, branch, and leaf). The SARF consisted of the metaheuristic to select the variables to be used in the RF. These methods were evaluated by the root mean square error (RMSE), coefficient of determination (R²), and residual graph. As a result, the pan-tropical equation demonstrated superior performance than the Spurr model due to its greater homogeneity of residues. The stepwise technique reduced the number of variables and the error of the estimates, mainly for the validation set. SARF showed better adjustments than RF, as it reduced in on average 99.2% of the number of variables and 9% of the error of estimates considering all compartments. In general, variables such as volume, basic wood density, canopy projection area, diameter at 0%, diameter at breast height, height, and latitude contributed strongly to the carbon independent of the tree compartment. Among the methods, SARF is an alternative to the traditional method, as it can extract accurate information from a large data set.

BASIC DENSITY AND SCALING OF JUVENILE AND MATURE WOOD IN PINUS CARIBAEA TREES

"The objective of the present study was to evaluate the density, and delimit the transition age and the volume proportion of wood types in Pinus caribaea trees. Trees from two genetic materials (A and B) were selected from a 20-year-old P. caribaea plantation. Disks from the base were used to determine the age of wood segregation and disks from different axial position – to determine the basic density and volume of juvenile, transition and mature wood in the trees. The density of the wood decreased from the base to the tree top. The juvenile wood corresponded to the beginning of the cambium activity until the eighth ring, the rest being characterized as transition wood and no mature wood was found in the 20-year-old P. caribaea trees. The proportion of juvenile wood volume in the genetic materials A and B was 58.57% and 80.51%. Transition wood was found up to 17.3 meters height of the trees."

Factors Influencing Directional Tree Felling in the Tapajós National Forest, Amazon, Brazil

Given its complexity, directional felling is considered one of the most dangerous activities in the exploratory phase of forest management projects for timber obtention. Therefore, detailed studies of the variables influencing its execution are necessary. The present research was conducted in the Tapajós National Forest, Brazilian Amazon, and analyzed 1,075 trees logged using the directional felling technique in a 504.30 ha area. To better understand directional felling, the studied variables were subjected to descriptive analyses and principal component analysis, a multivariate procedure that enables the simultaneous evaluation of several variables. While the diameter, basal area, and stem and branch volume explained most of the variability concerning directional felling, the commercial height influenced the least. Trees of the species Hymenolobium petraeum (angelim pedra) strongly correlated with the dendrometric variables diameter and stem and branch volume. Those of the species Hymenaea courbaril (jatobá) showed a strong correlation with the commercial height. Pseudopiptadenia psilostachya (fava timborana), Dipteryx odorata (cumaru), Hymenaea parvifolia (jutai mirim), and Astronium lecointei (muiracatiara) had a strong correlation with the basic wood density. Trees of the species Couratari guianensis (tauari), Lecythis pisonis (sapucaia), Astronium lecointei (muiracatiara), Mezilaurus itauba (itaúba), and Goupia glabra (cupiúba) showed lower correlations with the time needed for planning, cutting, and felling. They also had a reduced correlation with the angular differences between the natural and effective and the intended and effective felling directions. The latter results suggest that these species do not follow a defined pattern concerning the directional felling technique. However, trees of the other species followed a different tendency. In general, the logged trees lacked correlation with the directional felling cutting and total operation time. The analyses suggest that as the diameter of a tree increases, the chances of completing its directional felling decrease.