Goupia Glabra Research Articles

Thermal Decomposition and Kinetic Analysis of Amazonian Woods: A Comparative Study of Goupia glabra and Manilkara huberi

This study presents a detailed analysis of the thermal degradation and kinetic behavior of two Amazonian wood species, Goupia glabra (cupiúba) and Manilkara huberi (maçaranduba), using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR-ATR), and direct infusion mass spectrometry (DIMS). Wood samples were subjected to controlled heating rates of 20, 40, and 60 °C/min from 25 to 800 °C under an argon atmosphere. TGA revealed moisture evaporation below 120 °C, with hemicellulose degradation occurring between 220 and 315 °C, cellulose decomposition between 315 and 400 °C, and lignin breakdown over a broader range from 180 to 900 °C. The highest rate of mass loss occurred at 363.99 °C for G. glabra and 360.27 °C for M. huberi at a heating rate of 20 °C/min, with shifts to higher temperatures at faster heating rates. Activation energies were calculated using Arrhenius and Kissinger models, yielding values between 53.46–61.45 kJ/mol for G. glabra and 58.18–62.77 kJ/mol for M. huberi, confirming their stable thermal profiles. DSC analysis identified a significant endothermic peak related to moisture evaporation below 100 °C, followed by two exothermic peaks. For G. glabra, the first exothermic peak appeared at 331.45 °C and the second at 466.08 °C, while for M. huberi, these occurred at 366.41 °C and 466.08 °C, indicating the decomposition of hemicellulose, cellulose, and lignin. Enthalpy values for G. glabra were 12,633.37 mJ and 18,652.66 mJ for the first and second peaks, respectively, while M. huberi showed lower enthalpies of 9648.04 mJ and 14,417.68 mJ, suggesting a higher energy release in G. glabra. FTIR-ATR analysis highlighted the presence of key functional groups in both species, with strong absorption bands in the 3330–3500 cm−1 region corresponding to O-H stretching vibrations, indicative of hydroxyl groups in cellulose and hemicellulose. The 1500–1600 cm−1 region, representing aromatic C=C vibrations, confirmed the presence of lignin. Quantitatively, these results suggest a high content of cellulose and lignin in both species. DIMS analysis further identified polyphenolic compounds and triterpenoids in M. huberi, with major ions at m/z 289 and 409, while G. glabra showed steroidal and polyphenolic compounds with a base peak at m/z 395. These findings indicate the significant presence of bioactive compounds, contributing to the wood’s resistance to microbial degradation. This comprehensive thermal and chemical characterization suggests that both species have potential industrial applications in environments requiring high thermal stability.

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.

Carbonization temperature at 400°C and the behavior in the visual degradation of 15 wood species

Wood is an anisotropic material and its exposure to carbonization leads to reduced humidity and increased deformation due to the loss of its aesthetic and functional profile. Moisture may be an explanatory factor for the damage caused to the surface region of the coal. For this work, they were defined according to a basic density gradient, that is, involving species of low, medium and high densities, native and exotic, hardwood and conifers, as well as commercial and non-commercial uses. Among the species selected were: (Qualea sp.) Mandioqueira, (Aspidosperma sp.) Peroba, (Erisma uncinatum) Cedrinho, (Pinus elliotii) Pinus, (Eucalyptus.sp) Eucalipto, (Araucaria angustifolia) Pinheiro do Paraná, (Couratari sp.) Tauari, (Dipteryx sp.) Cumaru, (Tabebuia sp.) Ipê, (Peltogyne sp.) Roxinho, (Apuleia leiocarpa) Garapeira, (Goupia glabra) Cupiúba, (Astronium lecointei) Muiracatiara, (Hevea brasiliensis) Seringueira and (Schizolobium parahyba) Guapuruvu. At temperatures of 400 ºC, damage occurred in all species, with the influence of the temperature applied on the degradation suffered in the samples studied. The images produced can contribute to the understanding of charcoal as a material in its various temperature passages and thermal processes, in addition to analyzing the anatomy of charred samples, using the terms: ruptures and fissures as damage to charred wood as parameters.

Goupia glabra não recupera seu estoque de madeira após um ciclo de corte de 35 anos na Amazônia brasileira: evidências de monitoramento de longo prazo em múltiplas áreas

ABSTRACT Single-rule management is often adopted for various tropical forest timber species due to limited knowledge on species-specific growth and the relationship between logging intensity and recovery time. This study provides information to support sustainable management of Goupia glabra by simulating its wood stock recovery over a 35-year period following logging using data from six areas in the Brazilian Amazon. Monitoring periods after the first harvest cycle varyed from 16 to 29 years, and logging intensity from 0.000 to 0.696 m² ha-1. Tree density of G. glabra varied from 0 to 22 trees ha-1 and dominance from 0.00 to 7.39 m² ha-¹. Frequency of tree diameters was almost evenly distributed across diameter classes, slightly higher in the first (20-30 cm) class. These parameters generated estimations of recovery rate from 12 to 85%, showing that 35 years is insufficient for trees with DBH ≥ 20 cm in all study areas to grow and replace the stock of trees with DBH ≥ 50 cm harvested during the first cycle. Minimum recovery periods from 48 to 83 years were estimated to guarantee the recovery of the wood stock in the study areas. These findings reinforce the need to adapt management rules according to the population dynamics of each timber species and each logging area, and suggest the need for changes in the current legal requirements that define forest management in the Amazon.

Making wood inspection easier: FTIR spectroscopy and machine learning for Brazilian native commercial wood species identification.

The molecular structure of wood is mainly based on cellulose, lignin, and hemicellulose. However, low concentrations of lipids, phenolic compounds, terpenoids, fatty acids, resin acids, and waxes can also be found. In general, their color, smell, texture, quantity, and distribution of pores are used in human sensory analysis to identify native wood species, which may lead to erroneous classification, impairing quality control and inspection of commercialized wood. This study developed a fast and accurate method to discriminate Brazilian native commercial wood species using Fourier Transform Infrared Spectroscopy (FTIR) and machine learning algorithms. It not only solves the limitations of traditional methods but also goes beyond as it allows fast analyses to be obtained at low cost and high accuracy. In this work, we provide the identification of five Brazilian native wood species: Angelim-pedra (Hymenolobium petraeum Ducke), Cambara (Gochnatia polymorpha), Cedrinho (Erisma uncinatum), Champagne (Dipteryx odorata), and Peroba do Norte (Goupia glabra Aubl). The results showed the great potential of FTIR and multivariate analysis for wood sample classification; here, the Linear SVM differentiated the five wood species with an accuracy of 98%. The developed method allows industries, laboratories, companies, and control bodies to identify the nature of the wood product after being extracted and semi-manufactured.

Natural durability of 8 tropical species suitable for structural roundwood: laboratory screening tests for resistance to fungi and termites

Knowledge of the wood properties of tropical tree species is still relatively limited, so timber extraction focuses on a few abundant, large-diameter species. Very little is known about small-diameter trees, although they could be used directly as roundwood for construction. The aim of this study was to determine the natural durability of 8 candidate species for use as structural roundwood in French Guiana: Goupia glabra, Licania alba, Hymenopus heteromorphus, Lecythis persistens, Oxandra asbeckii, Pouteria bangii, Simarouba amara, Tachigali melinonii and Virola surinamensis. Samples of their wood were exposed to white rot (European and tropical), brown rot (European), and European subterranean termites (using non-choice and multi-choice tests) in laboratory conditions and subjected to screening tests adapted from European standards. Only two species were classified as durable against both fungi and termites: L. alba and P. bangii, which means they can be used without treatment as building material in tropical or temperate climates. The other species tested were classified (1) as durable but with notable differences observed in their resistance to fungi and termites respectively (G. glabra, L. persistens, O. asbeckii), (2) moderately durable (H. heteromorphus), (3) low durability to sensitive (T. melinonii, S. amara, V. surinamensis), meaning actual European standards would not let use these last species in outdoor structures without protection, despite their use by local population in traditional building. However, they could be used for building purposes with appropriate protection systems (including wood protection). The results we obtained for resistance to wood decay provide essential information to assess the potential of these eight tree species in French Guiana’s construction sector.

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.

Natural durability and improved resistance of 20 Amazonian wood species after 30 years in ground contact

Abstract This study aimed to assess the natural durability of 20 Amazonian wood species preserved with chromated copper arsenate (CCA) after 30 years in ground contact in an experimental field test at National Forest of Tapajós, Pará state - Brazil. Heartwood samples with a cross-section of 5 × 5 cm and 50 cm of length were half-buried in soil and inspected every year for decay. The species were classified according to natural durability following the classification method proposed by Findlay (Findlay, W.P.K. (1985). The nature and durability of wood. In: Findlay, W.P.K. (Ed.), Preservation of timber in the tropics. Springer Science, Whitchurch, pp. 1–13). After 30 years in ground test, six species were classified as Perishable, seven as Non-durable, three as Durable and four as Very durable, namely: Trichilia lecointei, Lecythis pisonis, Pseudopiptadenia suaveolens, and Dipteryx odorata (Very durable), Protium tenuifolium, Dinizia excelsa, and Ormosia paraensis (Durable), Endopleura uchi, Goupia glabra, Pouteria egregia, Tachigali chrysophylla, Tachigali paraensis, Vatairea sericea, and Vochysia maxima (Non-durable) and Chrysophyllum lucentifolium, Couratari oblongifolia, Didymopanax morototoni, Lueheopsis duckeana, Sterculia excelsa, and Xylopia nitida (Perishable). CCA preservative treatment was effective to promote timber protection, even under harsh climatic conditions of the Amazon forest environment.

EFFECT OF ARTIFICIAL WEATHERING ON PHYSICAL AND MECHANICAL PROPERTIES OF WOOD

ABSTRACT When wood is exposed outdoors, a combination of chemical and mechanical factors and solar radiation contribute to what is described as weathering, being the main degradation agent in this environment. This paper aims to investigate the effect of artificial weathering on mechanical and physical properties of Eucalyptus sp. and Cupiúba (Goupia glabra) woods simulating natural weathering effects. Samples were aged in UV radiation chamber with humidity and temperature control for 100, 200, 300 and 400 hours, considering aging cycles according to ASTM G154 (2006). Wood properties investigated were Conventional value of strength in static bending (fM), Modulus of elasticity in static bending (EM), strength in compression parallel to grain (fc0) and Janka Hardness (fH) according to ABNT NBT 7190 (1997). Effects of artificial weathering on wood properties were evaluated by statistical analysis at 5% significance level. Most of the wood properties investigated did not present significant changes with the aging performed, however, it was noted a decrease in the absolute values of the wood properties absolute values during the aging process. Only fH of Cupiúba wood aged for 100 and 200 hours presented significative performance loss at the significance level considered, which can be related to changes on the wood surface due to weathering exposure.

Spatial distribution of six managed tree species is influenced by topography conditions in the Central Amazon

In tropical forests, the spatial distribution of trees may present random, uniform, or grouped patterns that can simultaneously be affected by site and species characteristics. In Central Amazon, topographic gradients and soil water levels drive differences in tree species distribution and in forest dynamics at local scales. Knowing this kind of information can be useful for a forest manager to plan harvesting operations considering the microhabitat preference of merchantable species to reduce the disturbances caused by logging activities. Thus, the spatial variation of tree species is an important information to be considered to support the planning process of forest logging. The present study aims to evaluate the spatial distribution pattern of six species and analyze the relationship between the topography and the population densities and stem size of those species. The study was carried out in a forest production compartment managed by a private company located in the municipality of Silves, state of Amazonas, Brazil. The spatial pattern of the six species was characterized by Ripley's K function. Spatial distribution of diameter at breast height (DBH) and tree density based on kernel incidence calculation were evaluated for topographic classes of slope, elevation, and distance from streams, which were mapped using geographic information systems (GIS). The means of DBH and density of each species were compared among topographic classes by ANOVA and Tukey's test. The results demonstrated the predominance of the aggregate distribution pattern for the six species up to 1105 m (p < 0.01). The tree species Minquartia guianensis Aubl., Protium puncticulatum J.F.Macbr, Manilkara elata (Allemão ex Miq.) Monach, and Caryocar glabrum Aubl. Pers showed an increase in the tree density as the distance from the streams and elevation increased, standing spatially incident on plateaus. Kernel densities of Dinizia excelsa Ducke and Goupia glabra Aubl. were higher closer to streams. The DBH averages followed similar trends of population density for M. guianensis, M. elata, and C. glabrum, and the opposite pattern for D. excelsa, which presented larger individuals in less densely populated areas. P. puncticulatum and G. glabra mean DBH distribution was not affected by the topographic variables analyzed. Topography-related variables showed effects on variations of density and tree size, suggesting that species may be spatially sensitive to the habitat variability available in the study area. In view of logging planning, spatial distribution must be considered in decisions related to cutting down trees and maintenance of remaining trees, especially because some species are more aggregated in smaller scales. Moreover, as topographic variations affect the spatial distribution of size and density, the timber yield will vary spatially in the area, bringing implications for planning logging intensities, roads, skid trails and forest operations. Finally, the procedures and information generated in this study can be reproduced and applied to other species and managed areas to support the planning toward minimizing impacts on the spatial structure of commercial species, as well as to increase the chances of future stock recovery of managed forests in the Amazon.

Effects of Phylloicus case removal on consumption of leaf litter from two Neotropical biomes (Amazon rainforest and Cerrado savanna)

Phylloicus (Trichoptera, Calamoceratidae) is a stream invertebrate widely distributed across Neotropical biomes, which larvae use allochthonous leaf litter as food resource and to build a case that offers protection against predation. Seasonal changes in leaf litter accumulation on the streambed may affect Phylloicus larvae due to variations in availability of food and case-building material; however, it is unclear how these two processes influence each other. We assessed how case removal affected leaf litter consumption by Phylloicus larvae from two Neotropical biomes (Amazon rainforest and Cerrado savanna), which were experimentally offered leaf litter of Goupia glabra and Maprounea guianensis (common riparian species from the rainforest and savanna biomes, respectively). Our treatments included (i) direct effect of case removal, where larvae had their case removed during the experiment; (ii) time-lag effect, where the case was removed and larvae were allowed to rebuild the case before starting the experiment; and (iii) control, where cases were not removed. Leaf litter consumption by Phylloicus was 9.16 ± 7.47 mg/mg on average, being higher in the savanna than in the rainforest experiment (possibly in relation to a higher difference between the rainforest stream temperature and the experimental temperature, which may have inhibited larval activity), and higher on M. guianensis than on G. glabra (most likely due to the higher leaf litter quality of the former species). Consumption was higher in the time-lag effect treatment than in the direct effect and control treatments, which could be explained by an increase in the larval energetic demand for case building.

Slow rate of secondary forest carbon accumulation in the Guianas compared with the rest of the Neotropics.

Secondary forests are a prominent component of tropical landscapes, and they constitute a major atmospheric carbon sink. Rates of carbon accumulation are usually inferred from chronosequence studies, but direct estimates of carbon accumulation based on long-term monitoring of stands are rarely reported. Recent compilations on secondary forest carbon accumulation in the Neotropics are heavily biased geographically as they do not include estimates from the Guiana Shield. We analysed the temporal trajectory of aboveground carbon accumulation and floristic composition at one 25-ha secondary forest site in French Guiana. The site was clear-cut in 1976, abandoned thereafter, and one large plot (6.25ha) has been monitored continuously since. We used Bayesian modeling to assimilate inventory data and simulate the long-term carbon accumulation trajectory. Canopy change was monitored using two aerial lidar surveys conducted in 2009 and 2017. We compared the dynamics of this site with that of a surrounding old-growth forest. Finally, we compared our results with that from secondary forests in Costa Rica, which is one of the rare long-term monitoring programs reaching a duration comparable to our study. Twenty years after abandonment, aboveground carbon stock was 64.2 (95% credibility interval 46.4, 89.0) Mg C/ha, and this stock increased to 101.3 (78.7, 128.5) Mg C/ha 20 yr later. The time to accumulate one-half of the mean aboveground carbon stored in the nearby old-growth forest (185.6 [155.9, 200.2] Mg C/ha) was estimated at 35.0 [20.9, 55.9] yr. During the first 40yr, the contribution of the long-lived pioneer species Xylopia nitida, Goupia glabra, and Laetia procera to the aboveground carbon stock increased continuously. Secondary forest mean-canopy height measured by lidar increased by 1.14m in 8 yr, a canopy-height increase consistent with an aboveground carbon accumulation of 7.1Mg C/ha (or 0.89Mg C·ha-1 ·yr-1 ) during this period. Long-term AGC accumulation rate in Costa Rica was almost twice as fast as at our site in French Guiana. This may reflect higher fertility of Central American forest communities or a better adaptation of the forest tree community to intense and frequent disturbances. This finding may have important consequences for scaling-up carbon uptake estimates to continental scales.

INFLUENCE OF EXPOSURE TIME TO OPERATING TEMPERATURE ON SHEAR STRENGTH OF WOOD USED IN ROOF STRUCTURES

ABSTRACT Wood is one of the main materials used in the constructing of covering structures (roofs) because of its versatility. Under this situation, due to solar radiation incidence, the temperature can exceed 60 °C and, such as other environmental conditions, influence the mechanical properties of the wood in use. The aim of this research was to study the influence of exposure time of the wood of four different hardwood species at a temperature of 60 °C on the shear strength parallel to fibers. The wood of the following species was used: Cupiuba (Goupia glabra), Eucalyptus (Eucalyptus saligna), Garapeira (Apuleia leiocarpa), and Jatoba Tamarindo (Hymenaea sp.). In order to investigate the effect of exposure time (0, 168, 456, 720, and 2160 hours) of the wood species in an oven (60 °C) on the values of shear strength in the direction parallel to fibers, an analysis of variance (ANOVA) was carried out at 5% significance level. According to the results, the time the wood was exposed to the operating temperature significantly influenced the shear strength in the direction parallel to fibers. In addition, all species showed a decrease in shear strength after 456 hours of exposure at a constant temperature of 60 °C.

Soil nitrogen recovery and seasonal changes of xylem sap amino acids of Amazonian tree species following pasture abandonment

We conducted this study to understand the dynamics of revegetation by examining the levels of mineral nitrogen (NO3− and NH4+) in soil and the capacity of nitrogen use by the principal species growing in secondary forest in central Amazonia. For this, we measured the nitrate and ammonium content of soil, leaves and xylem sap, nitrate reductase activity of the leaves and free amino acid contents of the xylem sap in five tree species (Vismia cayennensis, Vismia japurensis, Bellucia dichotoma, Laetia procera and Goupia glabra) over a chronosequence during recovery after pasture abandonment at two seasons. Soil ammonium was higher in the dry season and nitrate higher in the wet season and increased these with pasture abandonment age. V. japurensis, B. dichotoma and G. glabra decreased foliar ammonium due to pasture abandonment in the dry season and foliar ammonium increased in L. procera in the wet season. V. japurensis and V. cayennensis showed a decrease in nitrate reductase activity, while B. dichotoma and L. procera showed an increase. Xylem nitrate decreased in L. procera and B. dichotoma in the dry and wet seasons, respectively, and ammonium increased only in V. japurensis and V. cayennensis in the wet. Xylem arginine increased in all plant species after a period of pasture abandonment (except B. dichotoma). Tree species growing in pasture abandoned areas didn’t show the same pattern of use of nitrogen, and this can be important in order to understand the nitrogen metabolism of trees in the Amazon region during forest restoration.

Multivariate analysis of native forest species in relation to chemical and texture attributes of soil in the region of Cotriguaçu – Mato Grosso State

This paper aimed to classify the forest species related to the demands on soil fertility and to identify groups with similar characteristics using multivariate statistical techniques. To do so, we analyzed soil samples for the texture and for chemical attributes and we carried out a phytosociological survey of the region. In the principal component analysis, the relations of the complex soil were summarized into four components, which together explained 80% of data variance, with most signifcant relationships between the sum of bases, base saturation, total cation exchange capacity, aluminum saturation, Ca + Mg, Al and clay, with correlation coeffcient greater than 90%. In hierarchical cluster analysis, 70% is similar to soil attributes; three distinct groups of forest species were formed. Multivariate analysis was effective in reducing the original variables, separation and classifcation of groups and identifcation of soil chemical properties most required by forest species. Groups 1 and 2 contain species more demanding in fertility, with preferences for medium textured soils and rich in calcium and magnesium bases. While Group 3 seems to be less demanding, with a predominance in sandy and acidic soils, with large cation exchange capacity and high aluminum saturation. Therefore, the species of the latter group can be indicated for the recovery of the degraded areas. The species Copaifera sp . and Goupia glabra deserve more studies about the mechanisms of adaptation to low soil fertility conditions.

Análise multivariada de espécies florestais nativas em relação aos atributos químicos e texturais do solo na região de Cotriguaçu – MT

Objetivou-se neste trabalho classificar as espécies florestais quanto às exigências em fertilidade do solo, bem como identificar grupos com características semelhantes utilizando técnicas da estatística multivariada. Para isso, foram analisadas amostras de solo quanto à textura e aos atributos químicos e realizado um levantamento fitossociológico da região. Na análise de componentes principais, as relações do complexo solo foram resumidas em quatro componentes que juntos explicaram 80% da variância dos dados, com relações mais significativas entre a soma de bases, saturação por bases, capacidade de troca catiônica efetiva, saturação por alumínio, Ca+Mg, Al e argila, com coeficiente de correlação maior que 90%. Na análise de agrupamento hierárquico, com 70% de similaridade quanto aos atributos do solo, formaram-se três grupos distintos de espécies florestais. A análise multivariada foi eficiente na redução das variáveis originais, separação e classificação dos grupos e identificação dos atributos químicos do solo mais requeridos pelas espécies florestais. Os Grupos 1 e 2 contêm espécies mais exigentes em fertilidade, com preferências por solos de textura média ricos em bases de cálcio e magnésio, enquanto o Grupo 3 parece ser menos exigente, prevalecendo em solos mais arenosos e mais ácidos, com grande capacidade de troca de cátions e elevada saturação por alumínio; podendo, as espécies desse último grupo, ser indicadas para recuperação de áreas degradadas. As espécies Copaifera sp. e Goupia glabra merecem mais estudos quanto aos mecanismos de adaptação às condições de baixa fertilidade do solo.

Time of exposure at 60 °C service temperature: Influence on strength and modulus of elasticity in compression parallel to the grain of hardwood species

The aim of this research was to determine the influence of exposure time at 60 °C in the compression strength parallel to the grain (fc0) and modulus of elasticity in compression parallel to the grain (Ec0) for cupiúba (Goupia glabra), eucalypt (Eucalyptus saligna), garapeira (Apuleia leiocarpa) and jatobá tamarindo (Hymeneae sp.) wood species. The factor investigated in this research was the residence time in kiln (exposure at controlled temperature 60 °C) of specimens: 0 (wood tested at room temperature and moisture content around to 12%), 168, 456, 720, and 2160 hours, simulating the reaction of the material in confined roof structures. Compression parallel to the grain tests were conducted according to the methods of the Brazilian Standard Code ABNT NBR 7190 (1997). ANOVA results indicated that the temperature (60 °C) had a significant influence in the five exposure times. All studied wood species showed an increase in the fc0 value with increasing time of exposure at 60 °C. For Ec0, this phenomenon occurred only for the jatobá tamarindo and cupiúba wood species.

Understanding the recruitment response of juvenile Neotropical trees to logging intensity using functional traits.

Selective logging remains a widespread practice in tropical forests, yet the long-term effects of timber harvest on juvenile tree (i.e., sapling) recruitment across the hundreds of species occurring in most tropical forests remain difficult to predict. This uncertainty could potentially exacerbate threats to some of the thousands of timber-valuable tree species in the Amazon. Our objective was to determine to what extent long-term responses of tree species regeneration in logged forests can be explained by their functional traits. We integrate functional trait data for 13 leaf, stem, and seed traits from 25 canopy tree species with a range of life histories, such as the pioneer Goupia glabra and the shade-tolerant Iryanthera hostmannii, together with over 30 yr of sapling monitoring in permanent plots spanning a gradient of harvest intensity at the Paracou Forest Disturbance Experiment (PFDE), French Guiana. We anticipated that more intensive logging would increase recruitment of pioneer species with higher specific leaf area, lower wood densities, and smaller seeds, due to the removal of canopy trees. We define a recruitment response metric to compare sapling regeneration to timber harvest intensity across species. Although not statistically significant, sapling recruitment decreased with logging intensity for eight of 23 species and these species tended to have large seeds and dense wood. A generalized linear mixed model fit using specific leaf area, seed mass, and twig density data explained about 45% of the variability in sapling dynamics. Effects of specific leaf area outweighed those of seed mass and wood density in explaining recruitment dynamics of the sapling community in response to increasing logging intensity. The most intense treatment at the PFDE, which includes stand thinning of non-timber-valuable adult trees and poison-girdling for competitive release, showed evidence of shifting community composition in sapling regeneration at the 30-yr mark, toward species with less dense wood, lighter seeds, and higher specific leaf area. Our results indicate that high-intensity logging can have lasting effects on stand regeneration dynamics and that functional traits can help simplify general trends of sapling recruitment for highly diverse logged tropical forests.

Understanding the Recruitment Response of Juvenile Neotropical Trees to Logging Intensity Using Functional Traits

Selective logging remains a widespread practice in tropical forests, yet the long-term effects of timber harvest on juvenile tree (i.e., sapling) recruitment across the hundreds of species occurring in most tropical forests remain difficult to predict. This uncertainty could potentially exacerbate threats to some of the thousands of timber-valuable tree species in the Amazon. Our objective was to determine to what extent long-term responses of tree species regeneration in logged forests can be explained by their functional traits. We integrate functional trait data for 13 leaf, stem, and seed traits from 25 canopy tree species with a range of life histories, such as the pioneer Goupia glabra and the shade-tolerant Iryanthera hostmannii, together with over 30 yr of sapling monitoring in permanent plots spanning a gradient of harvest intensity at the Paracou Forest Disturbance Experiment (PFDE), French Guiana. We anticipated that more intensive logging would increase recruitment of pioneer species with higher specific leaf area, lower wood densities, and smaller seeds, due to the removal of canopy trees. We define a recruitment response metric to compare sapling regeneration to timber harvest intensity across species. Although not statistically significant, sapling recruitment decreased with logging intensity for eight of 23 species and these species tended to have large seeds and dense wood. A generalized linear mixed model fit using specific leaf area, seed mass, and twig density data explained about 45% of the variability in sapling dynamics. Effects of specific leaf area outweighed those of seed mass and wood density in explaining recruitment dynamics of the sapling community in response to increasing logging intensity. The most intense treatment at the PFDE, which includes stand thinning of non-timber-valuable adult trees and poison-girdling for competitive release, showed evidence of shifting community composition in sapling regeneration at the 30-yr mark, toward species with less dense wood, lighter seeds, and higher specific leaf area. Our results indicate that high-intensity logging can have lasting effects on stand regeneration dynamics and that functional traits can help simplify general trends of sapling recruitment for highly diverse logged tropical forests.

Microorganisms that attack forest species in the north of the state of Mato Grosso

Sawnwood presents one of the main forest products commercialized in the northern region of southern Amazonia, but due to its anatomical, chemical and physical composition, it becomes a target of deterioration of xylophagous organisms in general, due to the presence of parenchyma tissue in its constitution , The arrangement of the elements gives greater or less resistance to the proliferation of fungi in the cell wall, since wood that has high volumes of extractives, become more resistant and gives the wood a lower degree of susceptibility to the development of organisms in the cellular wall of the wood, works which identify xylophagous organisms in wood, are still in the initial phase, with few scientific studies on species of commercial interest. Thus, the general objective of the work is to identify the microorganisms that attack the wood of native species of southern Amazonia, as well as to classify the types of fungi attack in the woods, for the development of the study, such as the following species: cedrinho (E risma uncinatum ); white cedar (E risma bicolor ); cupiuba (G oupia glabra ); Rosinha (V ochysia maxima ). Six genera of fungi under the wood solution were identified during the evaluation period: Trichorderma sp; P aecilomyces variotii; G raphium arrosporium; R hizoctonia solani; L asioplodia theobromae and F usarium sp . are that they are classified in relation to the damage of the wood as stains and emboloradores. T richorderma and P aecilomyces variotii are categorized as wood shapers, due to an increase in quality, a quality of the wood, thus reducing its technological properties.