Basic Density Research Articles

Alternative Tree Species for Sustainable Forest Management in the Brazilian Amazon

The scarcity of hardwoods from tropical forests makes the search for alternative species necessary for commercialization. This study aimed to establish groups of timber species from the Amazon Forest with potential for logging purposes through the assessment of their physical-mechanical properties, aiming to identify alternative species that can meet the market demands. We utilized data from the Forest Products Laboratory (LPF) (containing information on basic density and other wood mechanical properties) and the Timberflow platform, as well. We applied a multivariate cluster analysis technique with the aim of grouping species based on the technological characteristics of their wood and evaluating similarity among them to obtain homogeneous groups in terms of economic potential and utilization. The results indicated four homogeneous groups: Cluster 1 (40.72% of species, basic density-db: 690 kg m−3), Cluster 2 (13.92%, db: 260 and 520 kg m−3), Cluster 3 (27.32%, db: 550 and 830 kg m−3), and Cluster 4 (18.04%, db: 830 kg m−3). Most of the 20 listed species are classified as more commercially viable (70%), with high wood density. Species identified as alternatives include Dialium guianense and Zollernia paraensis for Dipteryx odorata, Terminalia argentea for Dinizia excelsa, Terminalia amazonia and Buchenavia grandis for Goupia glabra, and Protium altissimum and Maclura tinctoria for Hymenaea courbaril. The analysis highlighted the overexploitation of a restricted group of species and the need to find alternatives to ensure the sustainability of forest management. This study contributed to identifying species that can serve as alternatives to commercial ones, promoting a more balanced and sustainable forest management.

Early selection for rust resistance in eucalypt progenies and implications for other traits of interest in tree breeding

Planting of resistant clones is the main control strategy for rust caused by Austropuccinia psidii on eucalypts in Brazil. Phenotyping for resistance to rust is performed at the last stage of the breeding programme on genetic material preselected for growth and industrial traits, which therefore may include susceptible genotypes. An alternative way to increase the frequency of resistant individuals in the breeding population is to perform resistance phenotyping during the initial stages of the programme. However, the impact of this approach on other characteristics considered as priority in the selection of genetic material should be assessed. In this study, we evaluated whether early selection for resistance to rust influenced total diameter at breast height (DBH), height (TH), average annual increment (IMA) and basic wood density (BWD), which are important selection criteria in eucalypt breeding. For this, a total of 6 703 plants from 70 full-sib progenies of Eucalyptus grandis, E. urophylla and hybrids of these species were phenotyped for rust resistance before transplanting, under controlled conditions, and again at seven months after transplanting, under field conditions and natural infection. Subsequently, the breeding population was evaluated for BWD indirectly through pilodyn penetration at 24 months after planting, and for DBH, TH and MAI at 37 months. Considering the final phenotype, 25.3% individuals were classified as resistant and 74.7% were susceptible to rust. Comparative genetic analyses between resistant and susceptible individuals showed that selection for resistance, performed early, did not influence DBH, TH, MAI or BWD traits. Thus, the early selection of resistant genotypes speeds up the exclusion of susceptible genotypes, saving time and resources in the development of new commercial clones without interfering with other important traits for tree breeding.

Wood properties of three south american species planted in consortium

The use of tropical wood species in reforestation can be an alternative resource to meet the demand from the industrial wood sector. However, this strategy remains very limited, even while tropical forests continue to be deliberately exploited for the selective extraction of native species of highly commercial value. To test the potential of tropical species in reforestation, it is first necessary to evaluate the production and quality of the wood produced. Therefore, this study aimed to evaluate the quality Astronium urundeuva, Astronium fraxinifolium and Terminalia argentea woods, all aged 22 years, from a heterogeneous plantation located in the municipality of Selvíria-MS. From each species, 15 trees were selected. A 10 cm thick disc was removed from the base of each tree. Samples were taken from the discs near the bark region to evaluate the anatomical characteristics and the physical and mechanical properties of the wood. According to the results, it was found that only compressive strength did not differ significantly among the species. Astronium urundeuva presented the highest values for basic density and apparent density, and Terminalia argentea presented the highest values for fiber length, fiber wall thickness and vessel element diameter. The best Pearson correlations were found for basic density and apparent density, both for Astronium fraxinifolium and Astronium urundeuva. The best regression equations obtained were correlations between basic density and apparent density for Astronium fraxinifolium and Astronium urundeuva. The linear model best fits the data for these correlations. The greater growth of Terminalia argentea trees caused lower wood density owing to the lower rate of competition among trees. Based on the results and according to wood strength standards, the three species can be classified in the D40 strength class. According to the obtained results, these can support information to be compared with some species used commercially for structural purposes and other uses.

Reducing tree volume overestimation in quantitative structure models using modeled branch topology and direct twig measurements

Abstract Quantitative Structure Models (QSMs) are fit to tree point clouds to represent the topology of trees as a network of cylinders. QSMs allow for the calculation of metrics difficult to measure without destructive sampling, including total tree volume. Current limitations in terrestrial laser scanning technology make small branches difficult to accurately resolve, causing overestimation of small branch volume in QSMs, which can translate into overestimating tree biomass. We present a new method called Real Twig to correct overestimated small branch and twig cylinders in QSMs. Real Twig differs from current methods by using twig diameters measured directly from corresponding tree species to model a unique taper for every path in the QSM, using the QSM’s inherent branching topology, but without relying on predefined mathematical or allometric relationships. To test Real Twig, we generated QSMs for different sets of trees that had detailed dry mass and density measurements obtained via felling after scanning. QSM-based biomass estimates were obtained by multiplying the tree’s QSM-based volume estimate by the tree’s specific basic density value. We trained our method with high-quality data consisting of five northern red oak (Quercus rubra L.) and five red maple (Acer rubrum L.) trees, using two different versions of TreeQSM, a widely used algorithm for generating QSMs. We further tested our method on three publicly available datasets, including managed forests and large tropical trees, collected with both phase-shift or time-of-flight sensors. QSMs corrected with our Real Twig method showed a very large improvement in tree biomass estimation, with a relative mean error of −1.2%, a relative root mean square error of 10.5%, and a concordance correlation coefficient of 0.999, compared to a relative mean error 76.8%, a relative root mean square error of 48.7%, and a concordance correlation coefficient of 0.982, when using the standard outputs of TreeQSM.

EFFECTS OF THE CLIMATE GRADIENT ONF THE WOOD DENSITY OF Cedrela odorata L. IN THE NEOTROPICAL REGION

Understanding wood properties is crucial for optimizing its technological potential, enhancing both the effectiveness of use and product quality. Among these properties, density is regarded as one of the most significant. Numerous studies have documented the relationship between wood density and climate. However, the influence of climatic factors on the density variation of native species remains largely unexplored. Cedrela odorata L., a species traditionally logged in Brazil and widely distributed across the Neotropical region, requires further analysis to understand its potential response to varying climate patterns, thereby informing its management. This study aimed to determine the relationship between the basic density of Cedrela odorata L. and the climatic conditions in the Neotropical region. A comprehensive database was compiled from published scientific literature. Statistical analyses were conducted using Generalized Linear Models (GLM), with the best models selected based on the corrected Akaike Information Criterion (AICc). The presence of spatial patterns was assessed using Moran’s Index to verify spatial autocorrelation. The study identified significant relationships between the wood density of C. odorata and variables such as mean annual temperature and annual precipitation. The findings indicate a strong interaction between the climatic variables analyzed and the basic density of Cedrela odorata L. wood, with density being more sensitive to mean annual temperature.

Wood density and chemical composition variation of Eucalyptus urophylla clone in different environments

Abstract Variability in Eucalyptus wood density and chemical properties is crucial to understanding important factors for the forest-based industry, such as sampling methods and wood suitability as raw material. This study aimed to evaluate the basic density and chemical composition of the radial positions of young wood from the Eucalyptus urophylla clone grown under different precipitation levels. Trees from E. urophylla clonal plantations were collected in Inhambupe, Jandaíra and Itanagra, Bahia State, Brazil. Trees’ basic density and chemical composition (total extractive, lignin, hemicelluloses and α-cellulose) were determined based on the basal log of each tree, at four radial positions (1, 2, 3 and 4). It was found that the basic density and α-cellulose of wood are influenced by the cambial age and the site rainfall. There was greater increase in sections close to the bark (positions 1 and 4) and in more humid environments (sites Itanagra and Jandaríra). This finding highlights the association between wood basic density and chemical composition, mainly in the holocellulose content.

Physico-mechanical Properties and Potential Utilization of Melia azedarach L. Grown in Quezon Province, the Philippines

The possible utilization of Bagalunga (Melia azedarach L.) was determined based on its physical and mechanical properties. Tests were done following the ASTM D143-2019 standard. Tree samples were collected from two municipalities of Quezon province, the Philippines – namely Sariaya and Unisan. The results showed that compared to the trees from Sariaya, the trees collected from Unisan had 13.48 and 14.24% higher green moisture content (MC) and basic relative density (RD), respectively. However, their tangential (TS), radial (RS), longitudinal (LS), and volumetric shrinkage (VS) were 12.21, 4.42, 28.94, and 7.83% lower than those of the former. Furthermore, the RD of M. azedarach was similar to that of Gmelina arborea, and Acacia mangium and higher than that of Falcataria falcata. As for VS, it was comparable and in some cases even higher than those of commercially used timber species with medium to low VS. For the strength properties, in both green and 12% MC conditions, the strength of trees from Unisan was significantly higher than trees from Sariaya. However, both remained within the medium strength classification – similar to Swietenia macrophylla, G. arborea, and A. mangium but higher than Eucalyptus deglupta, Hevea brasiliensis, and F. falcata. The significant effect of axial height was observed in MC, RD, LS, and VS, and minimal variation was found in the mechanical properties. Industrial tree plantation developers may consider using M. azedarach as an alternative species, with careful consideration of the axial height and location, as these factors can influence tree properties.

Understanding the physical properties of multipurpose trees: A comprehensive analysis

The study was conducted at the Forest College and Research Institute in Tamil Nadu, India, to characterize the physical properties of eight different tree species: Tectona grandis, Swietenia macrophylla, Acrocarpusfraxinifolius, Artocarpus heterophyllus, Casuarina junghuhniana, Neolamarkiacadamba, Pterocarpus marsupium, and Melia dubia. One-meter billets were collected from felled trees of each species, debarked, and cleaned for analysis. The samples were prepared according to the requirements for assessing various physical properties, including bulk and basic density, moisture content, specific gravity, and shrinkage and swelling. The results indicated that all eight species exhibited high moisture content and medium-range density. Understanding these physical properties is crucial for determining the suitability of these species for use in the timber and furniture industries.

Flooding tolerance, biomass production, and leaf nitrogen assimilatory efficiency in 29 diverse willows (Salix spp.) genotypes during early growth

ABSTRACT Willows are frequently planted as unrooted cuttings in flood-prone areas. The occurrence of a flooding episode during the early stages of the plantation causes diverse morphological and physiological changes in willows. Thus, it is important to identify traits correlating to flooding tolerance to be used to breed genotypes with enhanced tolerance to this stress. In addition, flooding can change nitrogen absorption in plants, altering leaf nitrogen concentration. These changes could influence the photosynthetic activity, and ultimately, the growth of plantations. The aims of this work were: (i) to identify traits that increase flooding tolerance in willows during early growth and (ii) to analyze the effects of flooding on Assimilatory Nitrogen Use Efficiency (ANUE, measured as foliar biomass: foliar nitrogen concentration ratio). Two-month-old plants growing in pots of 29 willow genotypes were flooded with water covering 80% of the stem, for 43 days. At the end of this period, the flooding tolerance index (ratio between the flooded plant biomass to the non-flooded plant biomass) ranged between 39% and 103%. Flooding tolerance had a significant and positive correlation to plant height, diameter, total biomass, growth rate, leaf area, leaf number, and basic wood density. ANUE decreased in flooded plants in most genotypes, despite the increase in leaf nitrogen concentration. This implies that flooded plants were less efficient in the use of nitrogen to produce leaf biomass than the non-flooded treatment. These results are relevant for the selection of flooding tolerance in young willow plants obtained from rootless cuttings.

Combustion and energy performance of non-commercial Corymbia and Eucalyptus wood for use in cogeneration systems in Brazil

The increased representation of biomass in the Brazilian energy matrix will contribute to reducing dependence on hydroenergy and mitigating negative impacts during increasingly frequent drought periods. However, given the changing climate, it is urgent to classify and select new genotypes for the expansion of energy plantations. The objective of this study was to evaluate the energy performance and combustibility of wood from Eucalyptus and Corymbia trees to support a knowledge-based and efficient use of such woods in thermochemical conversion systems. Eight species of Eucalyptus (Eucalyptus amplifolia, E. longirostrata, E. major, and E. urophylla) and Corymbia (Corymbia citriodora, C. variegata, C. henryi, C. torelliana), which are not generally used for energy purposes, were selected at 6 years of age from experimental plantations in southeastern Brazil. Wood basic density (WBD), ash content (AC), higher heating value (HHV), fuel value index (FVI), ignition (Di), flammability (Ci) and combustion (Si) indexes were determined. The wood of E. urophylla and C. torelliana presented showed the highest and lowest FVI, respectively. Regarding combustion indexes E. longirostrata had a higher combustion index (4.00 ×107 %2/(min2°C3)), flammability (1.49 %min−1/°C2) and ignition (4.39 % min−3) while C. variegata presented the lowest values. The FVI showed correlations with the combustibility of wood. Thus, this index can be used for the rapid and reliable classification of new genetic materials for energy forests in Brazil. E. urophylla and E. longirostrata woods demonstrated better energy performance and combustion indexes, making them the most suitable species for use in cogeneration systems and candidates for the expansion of energetic forests in Brazil.

Особенности роста и структуры древесины сосны на вырубке и под пологом древостоя в условиях Республики Карелии

The intraspecific variability of the anatomical and hydraulic characteristics of xylem in the undergrowth in Scots pine (Pinus sylvestris L.) has been assessed during natural regeneration in the felling areas and under the canopy of a middle taiga blueberry pine forest in the conditions of the European North (Republic of Karelia). The influence of habitat conditions on the formation of structural elements of wood cells has been revealed. In felling areas under conditions of higher illumination, air and soil temperatures, the transition of pine undergrowth to the category of large with a height of more than 1.5 m occurs at the age of 6 years, whereas under the canopy of a mature stand the undergrowth reaches this category no earlier than 15 years. At the same time, in the 1st decade of growth under felling conditions, the growth of pine in diameter has been 4 times higher than that of pine under the canopy of a mature stand due to the formation of a larger number of rows of tracheids in the early and late zones. In addition, the pine undergrowth in the felling area has the highest potential hydraulic conductivity of the xylem, and, on the contrary, the lowest specific density of tracheids, the basic wood density and late wood content relative to the pine undergrowth under the canopy of the stand. The latter exhibited a significant decrease in the structural and functional characteristics of wood, with the exception of the thickness of the cell membranes of late tracheids. In the interanual dynamics, more stringent linear regression dependencies between the indices of early and late tracheids have been observed in pine undergrowth under the forest canopy. The results obtained indicate a greater correspondence of the environmental conditions in the felling area to the optimum for the growth and formation of wood of young pine trees relative to the conditions under the canopy of a mature blueberry pine forest. Inhibition of the growth activity of undergrowth under the canopy occurs due to high intraspecific competition from the dominant pine stand for light, moisture and soil nutrition.

Physical and Mechanical Properties of Juvenile Wood of Anadenanthera peregrina (L.) Speg. from Thinning

Reducing the rotation period through thinning and changing planting spacing can influence the technological properties of wood, with little attention paid to the effects of these variables on the raw material, which limits its processing in the wood sector. This work aimed to evaluate the physical and mechanical properties of wood from Anadenanthera peregrina juveniles thinned in three planting spacings (3 m × 3 m, 4 m × 4 m, and 5 m × 5 m). The physical properties in the base––top and pith––shell directions and the mechanical properties of the samples were evaluated. The results indicate better technological properties for wood withwith larger spacings. The physical properties showed decreasing trends in the base––top direction and increasing trends in the pith––bark direction, with a distinct trend in the degree of collapse. The average basic density of the different planting spacings varied between 0.47 g cm−3 and 0.63 g cm−3. The mechanical properties obtained for the 4 m × 4 m spacing were superior to those of the other spacings. Wood from young A. peregrina is an alternative for industrial processing, as wood from higher planting densities is more suitable for purposes that require resistance and rigidity.

NIR-based models for the evaluation of basic density, moisture and higher heating value of industrial wood chips

ABSTRACT The quick and efficient classification of wood is crucial for optimizing processes in forestry industries, which highlights the use of near infrared (NIR) spectroscopy. This study investigated the application of NIR spectroscopy for estimating the basic density, moisture content and calorific value of wood chips of Eucalyptus urophylla × E. grandis hybrids directly in the company yard. Using two lots of industrial chips collected in the company’s yard (Lots A and B), the NIR signatures were correlated with the results obtained by standard methods via Partial Least Squares Regression (PLS-R). The predictive models presented coefficients of determination (R²) of 0.83 for basic density (Lot A), 0.81 to 0.90 for moisture content (Lots A and B) and 0.74 for calorific value (Lot A). Variations in the moisture content of wood chips impacted the information quality of spectral signatures and thus the model accuracy, highlighting the difficulty of applying this technology in field conditions. However, the NIR models can be used as a solution for fast estimation of wood chips quality in the company yard, optimizing industrial processes.

Effects of blown sand and soil properties on the abrasion rate of compacted soil

Abrasion caused by blown sand is an important process for compacted soils in grasslands. The abrasion rate is affected by a combination of the blown sand intensity and the properties of the underlying soil, but there is a paucity of relevant studies of the simultaneous effects of these factors, especially quantitative ones. Our wind tunnel simulation experiments showed that the abrasion rate of compacted soil increased rapidly with increasing transport rate of the abrasive particles and with increasing soil texture index (δ = (sand% + silt%)/[clay% + organic matter% + CaCO3%]), and decreased significantly with increasing soil compaction. Accordingly, we developed an abrasion rate prediction model that accounted for the transport rate of windblown particles (abraders) and the physicochemical properties of the compacted soil. The effects of abrader properties (grain size and basic density), abrader availability, and a limited upwind supply of the abraders on the abrasion rate of compacted soils were also addressed. We developed a comprehensive abrasion-rate equation that accounted for both particle size and the basic density of the abraders.

Universal Basic Mass Density inside Dark Matter Halos

Abstract In this work we propose a universal basic mass density and a universal basic metric inside dark matter halos in the framework of Einstein equations providing an analytical ground for learning about dark matter. In a previous work the authors have proposed a simplified model for galaxies: a Schwarzschild black hole (that contains all the baryonic matter of the galaxy) immersed inside a dark matter halo. The solution solved the Einstein equations perturbatively and successfully gave the flat rotation curve and the baryonic Tully-Fisher relation, the two signatures of spiral galaxies. In this work we take the black hole mass (the baryonic mass) of the solution to be zero in order to focus our study on the dark matter halo exclusively. Among the results (1) is the prediction of a universal basic mass density of dark matter, ρ = a_0/2πGr, where a_0 ≈ 2.8×10^{-11} m/s^2 is a universal constant whose value was deduced from observations, (2) we show that the mass and velocity curve of the dark halo agree excellently with observational data at intermediate distances where the baryonic matter contribution is negligible, (3) we show that the constant a0is the origin of the constant surface density of dark matter and the origin of the scale-radius/scale-density scaling relation of the Navarro-Frenk-White profile (4) we show how the inclusion of baryonic matter in our model solves the core-cusp problem.

Correlation of anatomy with physical properties of wood species from an agroforestry system

When the premise is the best final use of wood, evaluation of anatomical variables is recommended, bearing in mind that they are correlated with the properties of this material. The present study aimed to evaluate the correlation between anatomy and the physical properties of wood from Parapiptadenia rigida (Benth.) Brenan, Peltophorum dubium (Spreng.) Taub., Eucalyptus grandis W. Hill × Eucalyptus urophylla S.T. Blake (hybrid) and Schizolobium parahyba (Vell.) Blake, from an agroforestry system. For this purpose, five trees of each species, aged 9 years old, were selected, and samples were collected from the diameter at 1.30 m height from the ground for analysis of the anatomical characteristics and physical properties of the wood. Anatomical variables, with the exception of fiber length and cell wall thickness, correlated with the physical properties of wood and influenced their values. The higher the cell wall fraction (0.79), vessel frequency (0.44) and ray frequency (0.92), the greater the basic density of the wood. The greater the fiber diameter (0.94), lumen diameter (0.88), vessel diameter (0.88), ray height (0.86) and ray width (0.84), the higher the moisture content of the wood.

Impact of age and genotype on the quality of eucalyptus wood for dissolving pulp

Wood properties for dissolving pulp production are little explored in wood quality research, mainly when it comes to eucalyptus trees. Therefore, the objective of the present study is to assess age and genotype impact on the quality of wood from young eucalyptus clones aimed at dissolving pulp production. Five trees from two clones, Eucalyptus urophylla (A) and E. urophylla x E. spp. (B), at the ages of 3 and 5 years, from crops located in Itanagra and Alagoinhas, Bahia State, Brazil, were assessed. Three wooden discs were removed from six trees at positions 0 %, 25 %, 50 %, 75 % and 100 % diameter at breast height (DBH) of the commercial height set for macroscopic characterization and wood chemical, physical and anatomical properties. Material age had impact on heartwood and bark production; and extractives, ash, xylans, galactans, arabinans rates, as well as wood vessels’ diameter and frequency. Genotypes had impact on extractives, lignin ash, hemicelluloses, xylans and galactans levels. Thus, wood chemical composition was the property most influenced by factors ‘age’ and ‘genotype’. Furthermore, clone A, at the age of 5 years, was the one with the greatest potential to dissolving pulp production, based on the following findings: the highest basic density (450 kg.m³), the highest glucans rate (48 %) and the lowest hemicellulose concentration (23 %).

Systematic optimization of culture media for maintenance of human induced pluripotent stem cells using the response surface methodology

The application of human induced pluripotent stem cells (hiPSCs) provides tremendous opportunities in cell therapy. However, culturing these cells faces many practical challenges, including costs associated with cell culture media and the optimization of cell culture conditions. Providing an optimized culture platform for hiPSCs to maintain pluripotency and self-renewal and generate cost-effective and robust therapeutics is an immediate requirement. This study used the design of experiments and the response surface methodology, a powerful statistical tool, to generate empirical models for predicting the optimal culture conditions of the hiPSCs. Pluripotency and cell proliferation were applied as read-outs to determine the optimal concentration of basic fibroblast growth factor (bFGF) and cell density. One model was defined to predict pluripotency and cell proliferation in terms of the predictor variables of the bFGF concentration and cell seeding density. Predicted culture conditions to maximize maintaining cell pluripotency were successfully validated. The present study's findings provide a novel approach that can potentially allow controllable hiPSC culture routine in translational research.

Evaluation of Deterioration Degree of Archaeological Wood from Luoyang Canal No. 1 Ancient Ship

This study provides a detailed investigation of archaeological wood samples from the Luoyang Canal No. 1 site, focusing on wood species identification, physical properties, mechanical property analyses, and morphological examination. The identified wood species, belonging to the Ulmus genus, exhibited a 43% decline in compressive strength in waterlogged environments. Further, the wood exhibited increased moisture content, higher porosity, reduced basic density, and elevated shrinkage rates, indicating a mild level of degradation. X-ray diffraction was employed for the observation of cellulose structure, and Fourier transform infrared spectroscopy (FT-IR) demonstrated significant removal of cellulose and hemicellulose components. These findings emphasize the importance of understanding wood degradation mechanisms to evaluate structural integrity and durability in guiding the development of effective preservation strategies for archaeological wood artifacts. Continued research and conservation are crucial to deepen our knowledge of wood deterioration processes and enhance the implementation of preservation techniques.

Cerrado Woods

The correct use of a particular species of wood depends on the knowledge of their physical properties for rational exploitation in a sustainable way. This study investigated the physical properties of Cerrado wood species and their potential to immobilize carbon. Ten trees of each species were felled, and five discs were removed from the main stem in longitudinal positions to determine the physical properties. The basic density was evaluated in all longitudinal positions, and the dimensional stability was only evaluated in the base discs. Carbon was estimated using a pantropical equation. The longitudinal density average was 0.599 g/cm³, with the Machaerium opacum species having the highest and Curatella americana the lowest average. The longitudinal variation of the wood basic density decreased from the bottom to the top of the tree in eight species. The mean radial retraction was 4.75%, with Magonia pubescens having the highest and Curatella americana the lowest average. The tangential retraction was 8.13%, with the highest being observed for Magonia pubescens and the lowest for Machaerium opacum. Magonia pubescens showed the highest carbon immobilization with 0.401 t/m3. Machaerium opacum and Jacaranda brasiliensis showed the best physical properties and the ability to immobilize carbon