RESUMO
The lignocellulosic materials of some plant species are rich in chemical compounds that can serve as a source of natural and environmentally less aggressive biocides for treating wood. The aim of this study was to verify the potential of the lignocellulosic materials (wood and bark) of Ateleia glazioviana and Hovenia dulcis as a natural wood preservative. The extracts were prepared by heating the materials to 100 °C at a concentration of 10%. The wood samples were treated in a laboratory autoclave using the empty cell method. Control samples (untreated) and samples treated with chromated copper borate - CCB (2.5%) were used as a comparison. The accelerated rot test in the laboratory was carried out using a sample of the colony of the white rot fungus, Trametes versicolor. Mass loss, solubility in 1% NaOH, scanning electron spectroscopy (SEM) and attenuated total reflection infrared spectroscopy (ATR-FTIR) were evaluated. A rotting field test was also carried out in a forest fragment for 180 days and the mass loss, apparent specific mass, ATR-FTIR, and dynamic bending of the wood samples were evaluated. In laboratory tests, natural extractive solutions from the bark and wood of Hovenia dulcis and only from the bark of Ateleia glazioviana have fungitoxic potential against the white rot fungus, when compared to material without preservative impregnations. The resistance of the wood in the field to rot did not obtain significant results with the application of the natural preservatives, and future studies will need to increase the concentration of the extracts in an attempt to improve their performance as natural biocides.
Assuntos
Lignina , Casca de Planta , Madeira , Madeira/química , Madeira/microbiologia , Lignina/farmacologia , Lignina/química , Lignina/análise , Casca de Planta/química , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Extratos Vegetais/farmacologia , Extratos Vegetais/químicaRESUMO
Wood and wood-based materials are commonly used for storage, but their surfaces are prone to biodegradation by microorganisms, especially fungi. This study focuses on the microbial communities on pine wood storage boxes treated with an anti-termite and mold solution in a tropical region in Dong Nai, Vietnam. We isolated 13 fungal strains from these surfaces and classified them into six genera: Rhizopus, Aspergillus, Fusarium, Curvularia, Penicillium, and Trichoderma. Enzyme activity tests revealed that strains Curvularia eragrostidis TD4.2 and Aspergillus sydowii TD5 were the most effective producers of cellulase, amylase, and laccase. Shotgun metagenomics analysis of the biological sample of the discolored surface of pine storage boxes indicated that Ascomycota was the dominant phylum, with Dothideomycetes and Sordariomycetes as the prevalent class. Aureobasidium (0.33%) and Chaetomium (1.1%) were the most abundant genera in the Dothideomycetes and Sordariomycetes, respectively. This research illustrates the complexity of microbial communities on wood surfaces, providing insights into the fungal dynamics affecting wooden storage materials in tropical climates.
Assuntos
Fungos , Pinus , Madeira , Vietnã , Fungos/classificação , Fungos/isolamento & purificação , Fungos/genética , Madeira/microbiologia , Pinus/microbiologia , Clima Tropical , MicobiomaRESUMO
Exploring new ecological and simultaneous processes to modify wood fibers (WF) by-products is a required pathway toward circular economy and sustainability. Thus, plasma-activated water (PAW) and ultrasound (U) were employed as alternative methods to modify WF in a continuous process. Such treatments promoted the etching and cavities on the WF surface that destabilized the hydrogen bonds of the hemicellulose and lignin molecules, increasing the cellulose fraction. The addition of modified WF in the PLA matrix increased the storage modulus (2937 up to 5834) and Young modulus (3990 up to 6000 MPa), indicating well fiber/matrix interactions. The results corroborated that the use of modified WF as fillers could reduce the cost of extruded PLA-based composites and expand the production of bio-based materials for the mobility or packaging field.
Assuntos
Biofilmes , Poliésteres , Água , Madeira , Madeira/química , Poliésteres/química , Água/química , Polissacarídeos/química , Lignina/química , Celulose/química , Ondas Ultrassônicas , Módulo de Elasticidade , Química Verde/métodosRESUMO
Developing the capacity to monitor species diversity worldwide is of great importance in halting biodiversity loss. To this end, remote sensing plays a unique role. In this study, we evaluate the potential of Global Ecosystem Dynamics Investigation (GEDI) data, combined with conventional satellite optical imagery and climate reanalysis data, to predict in situ alpha diversity (Species richness, Simpson index, and Shannon index) among tree species. Data from Sentinel-2 optical imagery, ERA-5 climate data, SRTM-DEM imagery, and simulated GEDI data were selected for the characterization of diversity in four study areas. The integration of ancillary data can improve biodiversity metrics predictions. Random Forest (RF) regression models were suitable for estimating tree species diversity indices from remote sensing variables. From these models, we generated diversity index maps for the entire Cerrado using all GEDI data available in orbit. For all models, the structural metric Foliage Height Diversity (FHD) was selected; the Renormalized Difference Vegetation Index (RDVI) was also selected in all species diversity models. For the Shannon model, two GEDI variables were selected. Overall, the models indicated performances for species diversity ranging from (R2 = 0.24 to 0.56). In terms of RMSE%, the Shannon model had the lowest value among the diversity indices (31.98%). Our results suggested that the developed models are valuable tools for assessing species diversity in tropical savanna ecosystems, although each model can be chosen based on the objectives of a given study, the target amount of performance/error, and the availability of data.
Assuntos
Biodiversidade , Árvores , Clima Tropical , Árvores/classificação , Tecnologia de Sensoriamento Remoto/métodos , Pradaria , Ecossistema , Imagens de Satélites , MadeiraRESUMO
Along their lengths, stems experience different functional demands. Because bark and wood traits are usually studied at single points on stems, it remains unclear how carbon allocation changes along tip-to-base trajectories across species. We examined bark vs wood allocation by measuring cross-sectional areas of outer and inner bark (OB and IB), IB regions (secondary phloem, cortex, and phelloderm), and wood from stem tips to bases of 35 woody angiosperm species of diverse phylogenetic lineages, climates, fire regimes, and bark morphologies. We examined how varied bark vs wood allocation was and how it was affected by precipitation, temperature, soil fertility, leaf habit, and fire regime. Allocation to phloem (relative to wood) varied little across species, whereas allocation to other tissues, strongly affected by the environment or shed in ontogeny, varied widely. Allocation to parenchyma-rich cortex and phloem was higher at drier sites, suggesting storage. Higher allocation to phloem and cortex also occurred on infertile soils, and to phloem in drought-deciduous vs cold-deciduous and evergreen species. Allocation to OB was highest at sites with frequent fires and decreased with fire frequency. Our approach contextualizes inferences from across-species studies, allows testing functional hypotheses, and contributes to disentangling the functional roles of poorly understood bark tissues.
Assuntos
Carbono , Casca de Planta , Casca de Planta/fisiologia , Carbono/metabolismo , Floema/metabolismo , Floema/fisiologia , Madeira/fisiologia , Solo/química , Magnoliopsida/fisiologia , Incêndios , Folhas de Planta/fisiologia , Folhas de Planta/metabolismo , Especificidade da Espécie , FilogeniaRESUMO
This work aimed to get compost with cellulose-rich residues for Pycnoporus sanguineus basidiocarp production. Two isolates of P. sanguineus (Ps08 and Ps14) were grown in polypropylene bags containing sawdust of Eucalyptus sp. and rice bran in rates of zero, 5% and 20%, and humidity of 75%. We used two granulometries of sawdust, less than 500 µm and between 500 and 841 µm, compress to get a density of 0.5 g mL-1. Basidiocarps were harvested at 90 and 180 days of incubation, evaluating quantity, diameter, fresh and dry masses and production of the pigment cinnabarin. For the variable granulometry, there was an effect only for the isolate Ps14, which produced basidiocarps with diameters 14.65 mm in granulometry less than 500 µm and 8.56 in granulometry 500-841 µm, however, comparing the isolates, Ps08 produced larger basidiocarps, with an average diameter of 36.99 mm while 11.60 mm for Ps14. Only the isolate Ps08 responded in a dose-dependent manner to rice bran concentrations. As for the fresh mass of basidiocarps, in both harvests the isolate Ps08 presented higher values than the isolate Ps14 in the first and second harvests, in the granulometry less than 500 µm. The cinnabarin content of Ps14 isolate was higher than Ps08, with values of 0.67 e 0.43 mg mL-1, respectively, in the granulometry 500-841 µm, with a tendency to increase in cinnabarin content with higher additions of rice bran. Thus, it was possible to produce basidiocarps of P. sanguineus in an axenic way using cellulosic residues supplemented with rice bran.
Assuntos
Compostagem , Oryza , Pycnoporus , Pycnoporus/metabolismo , Eucalyptus , Carpóforos/crescimento & desenvolvimento , Madeira/química , Solo/química , Microbiologia do Solo , Celulose/metabolismoRESUMO
Mangrove forests are essential on the Amazon coast, as local communities widely use their wood. However, it is still necessary to understand the mechanical properties of wood typical of mangroves. Our main objective was to understand the influence of density on mechanical properties. Then, we tested the hypothesis that wood density has a stronger influence on the mechanical properties of R. mangle trees. Five trees of each dominant mangrove species were cut, and the mechanical properties of wood from these species were analyzed according to ASTM D143-14. Rhizophora mangle wood presented the highest average values compared to other mangrove species for mechanical properties (ρ12% = 1031.6 kg m-3; fv0 = 21.8 Mpa; fc0 = 79.6 Mpa; fM = 190.0 Mpa; EM0 = 18.8 Gpa), as well as for resistance and rigidity. Wood from mangrove trees on the Amazon coast has the same trend of mechanical properties as trees from Asian mangroves. Avicennia germinans and Laguncularia racemosa have a moderate rating. Rhizophora mangle stands out for presenting the highest values of these properties, with the species of Rhizophoraceae being considered the most resistant wood among mangrove species worldwide.
Assuntos
Rhizophoraceae , Madeira , Rhizophoraceae/fisiologia , Áreas Alagadas , Avicennia/fisiologia , Árvores , BrasilRESUMO
Amazonian species are generally unable to adapt to long drought periods, indicating a low capacity to adjust their hydraulic traits. Secondary forests account for 20% of forest cover in the Amazon, making natural regeneration species crucial under climate change scenarios. In this study, we compared the hydraulic traits of five species, including non-pioneers (Bertholletia excelsa Bonpl., Carapa guianensis Aubl., Hymenaea courbaril L.) and pioneers [Cedrela fissilis Vell., Tabebuia rosea (Bertol.) Bertero ex A.DC.], across light conditions (understory, intermediate, gap) in a 22-year-old secondary forest in Central Amazon, Brazil. Twenty-five saplings were planted and monitored in 3 plots × 5 blocks. Five years after the plantation, we assessed growth, wood density, leaf water potential at predawn and midday, xylem embolism resistance (P50), and hydraulic safety margins (HSM). The leaf water potential ranged from -2.9 to 0 MPa. The non-pioneer species C. guianensis and H. courbaril exhibited the lowest P50 (-4.06 MPa), indicating higher embolism resistance, whereas the pioneer T. rosea had the highest P50 (-1.25 MPa), indicating lower resistance. The HSM varied from -1.60 to 3.26 MPa, with lower values in gap conditions during the dry period (-1.60 MPa), especially affecting pioneer species. Wood density was influenced by both light and species type, with non-pioneers showing a generally higher density, with H. courbaril reaching 0.75 g cm-3 in the understory while the pioneer T. rosea showed the lowest density (0.27 g cm-3). These results highlight that light conditions affect hydraulic traits differently across species strategies, especially during early growth. Non-pioneer, slow-growing native species appear more resilient to light variation, making them suitable for future plantations aimed at climate adaptation in secondary forests.
Assuntos
Florestas , Luz , Árvores , Árvores/fisiologia , Árvores/crescimento & desenvolvimento , Brasil , Água/fisiologia , Hymenaea/fisiologia , Hymenaea/crescimento & desenvolvimento , Folhas de Planta/fisiologia , Folhas de Planta/crescimento & desenvolvimento , Cedrela/fisiologia , Cedrela/crescimento & desenvolvimento , Madeira/fisiologiaRESUMO
Auricularia cornea has become one of the most important cultivated mushrooms worldwide. Although not remarkably flavorful, Auricularia species are very versatile and rehydrate easily after drying, adding a unique and pleasing texture to the dishes. In this study, we collected, identified, and domesticated a wild strain of A. cornea from the Brazilian Atlantic Rainforest. The wild strain was evaluated for mycelial growth at different temperatures and substrates, biological efficiency, and nutritional composition. The temperature that best favored the A. cornea mycelium growth was 30 °C, and the substrate was sterile Eucalyptus sawdust. The highest biological efficiency value obtained was 106.90 ± 13.28%. Nutritional analysis showed that the produced wood ears contained 71.02% carbohydrates, 19.63% crude fiber, 11.59% crude protein, 10.19% crude fat, and 4.24% ash on dry matter basis. For the mineral content profile, the elements K and P were the most abundant. This is the first report on cultivation of a wild strain of A. cornea from Brazil.
Assuntos
Madeira , Brasil , Madeira/microbiologia , Basidiomycota/crescimento & desenvolvimento , Basidiomycota/classificação , Micélio/crescimento & desenvolvimento , Temperatura , Eucalyptus/microbiologia , Eucalyptus/crescimento & desenvolvimento , Floresta ÚmidaRESUMO
Although woodpeckers are known to forage in decaying trees, their contribution to internal wood decay is not well known. In this sense, non-destructive techniques for structural wood degradation provide an opportunity to quantitatively assess the role of woodpeckers in tree decay. We used sonic tomography to test that the trunks of living trees pecked by Magellanic woodpeckers show pronounced decay, which accelerates under environmental conditions favorable to wood-decaying fungi. The internal decomposition of wood and its decay rate were measured over four years on 156 living southern beech (Nothofagus) trees belonging to four dominant species of southern temperate forests in northern Patagonia. Half of these live trees had woodpecker feeding holes, while the rest served as controls. The percentage of decayed wood, although not severely decayed, increased in sections with the presence of woodpecker holes, but was also influenced by temperatures and biophysical variables such as elevation and topography. The trunk sections with woodpecker holes and exposed to intensive foraging showed accelerated inter-annual decay. Woodpecker foraging activity interacted with vegetation characteristics, resulting in accelerated wood decay in forest sites with an open canopy and exposed to water stress. Thus, sonic tomography provided evidence of a close relationship between woodpeckers and internal wood decomposition, suggesting a positive feedback mechanism regulated by forest disturbance. The approach used here can be extended to gain insight into the influence of woodpeckers on tree decay and mortality in regions experiencing severe drought and forest degradation, such as northern Patagonia.
Assuntos
Fagus , Florestas , Madeira , Animais , Argentina , Árvores , Comportamento Alimentar , Monitoramento AmbientalRESUMO
Fungi (Neolentinus lepideus, Nl, and Trametes versicolor, Tv) impart wood rot, leading to economic and environmental issues. To overcome this issue, toxic chemicals are commonly employed for wood preservation, impacting the environment and human health. Surface coatings based on antimicrobial chitosan (CS) of high molar mass (145 × 105 Da) were tested as wood preservation agents using an innovative strategy involving ultra-pressurizing CS solutions to deposit organic coatings on wood samples. Before coating deposition, the antifungal activity of CS in diluted acetic acid (AcOOH) solutions was evaluated against the rot fungi models Neolentinus lepideus (Nl) and Trametes versicolor (Tv). CS effectively inhibited fungal growth, particularly in solutions with concentrations equal to or higher than 0.125 mg/mL. Wood samples (Eucalyptus sp. and Pinus sp.) were then coated with CS under ultra-pressurization at 70 bar. The polymeric coating deposition on wood was confirmed through X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM) images, and water contact angle measurements. Infrared spectroscopy (FTIR) spectra of the uncoated and coated samples suggested that CS does not penetrate the bulk of the wood samples due to its high molar mass but penetrates in the surface pores, leading to its impregnation in wood samples. Coated and uncoated wood samples were exposed to fungi (Tv and Nl) for 12 weeks. In vivo testing revealed that Tv and Nl fungi did not grow on wood samples coated with CS, whereas the fungi proliferated on uncoated samples. CS of high molar mass has film-forming properties, leading to a thin hydrophobic film on the wood surface (water contact angle of 118°). This effect is mainly attributed to the high molar mass of CS and the hydrogen bonding interactions established between CS chains and cellulose. This hydrophobic film prevents water interaction, resulting in a stable coating with insignificant leaching of CS after the stability test. The CS coating can offer a sustainable strategy to prevent wood degradation, overcoming the disadvantages of toxic chemicals often used as wood preservative agents.
Assuntos
Quitosana , Interações Hidrofóbicas e Hidrofílicas , Madeira , Quitosana/química , Quitosana/farmacologia , Madeira/química , Madeira/microbiologia , Antifúngicos/farmacologia , Antifúngicos/química , Propriedades de Superfície , PolyporaceaeRESUMO
In tropical forests, trees strategically balance growth patterns to optimise fitness amid multiple environmental stressors. Wind poses the primary risk to a tree's mechanical stability, prompting developments such as thicker trunks to withstand the bending forces. Therefore, a trade-off in resource allocation exists between diameter growth and vertical growth to compete for light. We explore this trade-off by measuring the relative wind mortality risk for 95 trees in a tropical forest in Panama and testing how it varies with tree size, species and wind exposure. Surprisingly, local wind exposure and tree size had minimal impact on wind mortality risk; instead, species wood density emerged as the crucial factor. Low wood density species exhibited a significantly greater wind mortality risk, suggesting a prioritisation of competition for light over biomechanical stability. Our study highlights the pivotal role of wind safety in shaping the life-history strategy of trees and structuring diverse tropical forests.
Assuntos
Florestas , Árvores , Clima Tropical , Vento , Árvores/crescimento & desenvolvimento , Panamá , MadeiraRESUMO
Termites of the genus Nasutitermes sp. (Blattodea: Termitidae), which feed on cellulose, may cause wood to become brittle and fragile. This study aimed to evaluate the natural resistance of three native wood species: Magonia pubescens (Sapindaceae), Dalbergia nigra and Machaerium amplum (Fabaceae) to attack by Nasutitermes sp. termites and to investigate the relationship between resistance, extractive content, and oven-dry density. Samples of each wood species were subjected to a forced feeding process with Nasutitermes sp. termites for 30 days. Following the exposure, the oven-dry density, extractive content, percentage of wood loss, and termite mortality were determined for each sample. Dalbergia nigra exhibited resistance to termite attack and had the highest extractive content at 13.14%. Conversely, M. amplum had the highest wood loss at 5.37% and the lowest extractive content at 1.94%. Both species showed a negative correlation between wood loss and extractive content, but no correlation with wood density. Magonia pubescens had the highest density at 0.90 g/cm3. Macherium amplum and M. pubescens caused 100% termite mortality, while D. nigra caused 40% mortality.
Assuntos
Fabaceae , Isópteros , Sapindaceae , Madeira , Animais , Isópteros/fisiologia , Fabaceae/classificação , Dalbergia , Comportamento Alimentar/fisiologiaRESUMO
The variation within and across species has afterlife effects on carbon and nutrient cycling through the alteration of litter decomposability. However, the focus on leaves may not reflect a whole-plant economic spectrum of strategies. Here, we assessed the patterns and predictors of flower and leaf-litter decomposition at the intra- (i.e., flowers and leaves of the same species) and inter-specific (i.e., flowers and leaves from different species) levels for 29 tropical woody species in northeast Brazil. We evaluated nine functional litter traits, including structural and chemical traits. Flower litter decomposed, on average, three times faster than leaf litter (11.9% and 39.4% mass remaining, respectively) and exhibited higher water-holding capacity (WHC), leaching (LEA), and N, P, and K content. Otherwise, leaf litter showed higher density (DEN) and Ca, Mg, and Na content. The average relative differences in decomposition rate and functional traits between flower and leaf litter did not differ at both intra- and inter-specific levels. The predictors of decomposition were mostly similar, explaining 39% and 37% of flower and leaf litter, respectively. Leaching, P, Ca, Mg, and Na predict both flower and leaf-litter decomposition. However, WHC exclusively predicted flower-litter decomposition, and DEN, N, and K exclusively predicted leaf-litter decomposition. The observed differences in decomposition rate and functional traits between flower and leaf litter indicate that the afterlife effects differ between these plant organs and leverage the role of flower litter and its secondary consequences to nutrient and carbon cycling on ecosystems.
Assuntos
Flores , Folhas de Planta , Brasil , Madeira , Clima TropicalRESUMO
Nineteen isolates representing a candidate for a novel yeast species belonging to the genus Spencermartinsiella were recovered from rotting wood samples collected at different sites in Atlantic Rainforest and Amazonian Forest ecosystems in Brazil. Similarity search of the nucleotide sequence of the intergenic spacer (ITS)-5.8S and large subunit D1/D2 regions of the ribosomal gene cluster showed that this novel yeast is closely related to Spencermartinsiella cellulosicola. The isolates differ by four nucleotide substitutions in the D1/D2 domain and six substitutions and 31 indels in the ITS region from the holotype of S. cellulosicola. Phylogenomic analysis based on 1474 single-copy orthologues for a set of Spencermartinsiella species whose whole genome sequences are available confirmed that the novel species is phylogenetically close to S. cellulosicola. The low average nucleotide identity value of 83% observed between S. cellulosicola and the candidate species confirms that they are distinct. The novel species produced asci with hemispherical ascospores. The name Spencermartinsiella nicolii sp. nov. is proposed. The holotype is CBS 14238T. The MycoBank number is MB855027. Interestingly, the D1/D2 sequence of the S. nicolii was identical to that of an uncultured strain of Spencermartinsiella causing systemic infection in a male adult crocodile (Crocodylus niloticus). The characterization of some virulence factors and antifungal susceptibility of S. nicolii isolates suggest that this yeast may be an opportunistic pathogen for animals, including humans; the isolates grow at 37 °C.
Assuntos
DNA Fúngico , Filogenia , Saccharomycetales , Análise de Sequência de DNA , Madeira , Brasil , Madeira/microbiologia , DNA Fúngico/genética , Saccharomycetales/genética , Saccharomycetales/isolamento & purificação , Saccharomycetales/classificação , Técnicas de Tipagem Micológica , DNA Espaçador Ribossômico/genética , Floresta Úmida , FlorestasRESUMO
This study aims to conduct an applied and innovative investigation to enhance the energy quality of wood residues through hydrothermal carbonization pretreatment. For this purpose, the treatment was carried out at three different temperatures: 180, 220, and 240 °C under autogenous pressure. The in natura material and the hydrochars were characterized, and thermogravimetric analyses were performed in an O2 atmosphere with heating rates of 2.5, 5, 10, and 20 °C min-1. The global activation energy for natura biomass combustion was determined to be 112.49 kJ.mol-1. On the other hand, the hydrothermal carbonization process promoted a reduction in this value for the 94.85 kJ.mol-1. The conversion function for the in natura biomass was characterized as 1 - α , order 1, while the hydrochars was 2(1-α) [-ln(1-α)] (1/2), Avrami-Erofe'ev I. Triple kinetic parameters were ascertained, and the conversion curves along with their respective derivatives were modeled, exhibiting minimal deviations between theoretical and experimental data. This facilitated the mathematical representation of the reaction processes and allowed for a comprehensive comparison of the results.
Assuntos
Termogravimetria , Cinética , Biomassa , Madeira/química , Carvão Vegetal/químicaRESUMO
Wood serves crucial functions in plants, yet our understanding of the mechanisms governing the composition, arrangement, and dimensions of its cells remains limited. The abrupt transition from nonlianescent to lianescent xylem in lianas represents an excellent model to address the underlying mechanisms, although consistent triggering factors for this process remain uncertain. In this study we examined how physical support attachment impacts the development of lianescent xylem in Bignonia magnifica (Bignoniaceae), employing a comprehensive approach integrating detailed anatomical analysis with gene expression profiling of cambium and differentiating xylem. Our findings demonstrate that attachment to physical supports triggers the formation of lianescent xylem, leading to increased vessel size, broader vessel distribution, reduced fibre content, and higher potential specific water conductivity than nonlianescent xylem. These shifts in wood anatomy coincide with the downregulation of genes associated with cell division and cell wall biosynthesis, and the upregulation of transcription factors, defense/cell death, and hormone-responsive genes in the lianescent xylem. Our findings provide insights into the regulation of xylem differentiation, driven by response to environmental stimuli. Additionally, they shed light on the mechanisms underlying the adaptation of lianas to climbing.
Assuntos
Câmbio , Regulação da Expressão Gênica de Plantas , Xilema , Xilema/fisiologia , Xilema/anatomia & histologia , Câmbio/genética , Câmbio/crescimento & desenvolvimento , Transcriptoma , Madeira/anatomia & histologia , Madeira/genética , Madeira/fisiologia , Diferenciação Celular/genética , Perfilação da Expressão Gênica , Parede Celular/metabolismoRESUMO
Background: Plants allocate resources to growth, defense, and stress resistance, and resource availability can affect the balance between these allocations. Allocation patterns are well-known to differ among species, but what controls possible intra-specific trade-offs and if variation in growth vs. defense potentially evolves in adaptation to resource availability. Methods: We measured growth and defense in a provenance trial of rubber trees (Hevea brasiliensis) with clones originating from the Amazon basin. To test hypotheses on the allocation to growth vs. defense, we relate biomass growth and latex production to wood and leaf traits, to climate and soil variables from the location of origin, and to the genetic relatedness of the Hevea clones. Results: Contrary to expectations, there was no trade-off between growth and defense, but latex yield and biomass growth were positively correlated, and both increased with tree size. The absence of a trade-off may be attributed to the high resource availability in a plantation, allowing trees to allocate resources to both growth and defense. Growth was weakly correlated with leaf traits, such as leaf mass per area, intrinsic water use efficiency, and leaf nitrogen content, but the relative investment in growth vs. defense was not associated with specific traits or environmental variables. Wood and leaf traits showed clinal correlations to the rainfall and soil variables of the places of origin. These traits exhibited strong phylogenetic signals, highlighting the role of genetic factors in trait variation and adaptation. The study provides insights into the interplay between resource allocation, environmental adaptations, and genetic factors in trees. However, the underlying drivers for the high variation of latex production in one of the commercially most important tree species remains unexplained.
Assuntos
Hevea , Látex , Folhas de Planta , Hevea/genética , Hevea/crescimento & desenvolvimento , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Látex/metabolismo , Biomassa , Madeira/genética , Filogenia , Especificidade da EspécieRESUMO
BACKGROUND: The interplay between different uses of woody plants remains underexplored, obscuring our understanding of how a plant's value for one purpose might shield it from other, more harmful uses. This study examines the protection hypothesis by determining if food uses can protect woody plants (trees and shrubs) from wood uses. We approached the hypothesis from two distinct possibilities: (1) the protective effect is proportional to the intensity of a species' use for food purposes, and (2) the protective effect only targets key species for food purposes. METHODS: The research was conducted in a rural community within "Restinga" vegetation in Northeast Brazil. To identify important food species for both consumption and income (key species) and the collection areas where they naturally occur, we conducted participatory workshops. We then carried out a floristic survey in these areas to identify woody species that coexist with the key species. Voucher specimens were used to create a field herbarium, which, along with photographs served as visual stimuli during the checklist interviews. The interviewees used a five-point Likert scale to evaluate the species in terms of perceived wood quality, perceived availability, and use for food and wood purposes. To test our hypothesis, we used Cumulative Link Mixed Models (CLMMs), with the wood use as the response variable, food use, perceived availability and perceived quality as the explanatory variables and the interviewee as a random effect. We performed the same model replacing food use for key species food use (a binary variable that had value 1 when the information concerned a key species with actual food use, and value 0 when the information did not concern a key species or concerned a key species that was not used for food purposes). RESULTS: Consistent with our hypothesis, we identified a protective effect of food use on wood use. However, this effect is not directly proportional to the species' food use, but is confined to plants with considerable domestic food importance. Perceived availability and quality emerged as notable predictors for wood uses. CONCLUSION: We advocate for biocultural conservation strategies that enhance the food value of plants for their safeguarding, coupled with measures for non-edible woody species under higher use-pressure.
Assuntos
Conservação dos Recursos Naturais , Plantas Comestíveis , Madeira , Brasil , Humanos , Etnobotânica , ÁrvoresRESUMO
For the Caatinga vegetation, it has not yet been definitively established which adaptive strategies best define the functional groups of woody plants and which syndromes emerge from the relationships between functional traits to achieve success in a semi-arid tropical region. To fill some of these gaps, we analyzed a specific set of characteristics that make up the LHS scheme of the plant ecological strategy (leaf-heigh-seed). The LHS scheme captures the functional niche of plants regarding the functional traits specific leaf area (SLA), plant height (HE), and seed mass (SM). We associate wood density (WD) to this scheme because this trait is a key feature for the identification of functional strategies in seasonally dry vegetation such as the Caatinga. We measured these characteristics in eight woody species and classified them according to their leaf phenology into deciduous and evergreen. The experiment was carried out between December 2017 and November 2018 in Caatinga areas located in the municipality of Barra de Santana, PB, a semiarid region of Brazil. Using cluster analysis, principal component analysis (PCA) and Pearson correlation analyses, we found significant relations between SLA and SM, and HE and WD. The SLA was the main predictor of plant strategy in the Caatinga. According to this characteristic, we identified two functional groups: species with a low SLA and species with a high SLA. We also recognized differences between deciduous and evergreen species based on the same trait. The traits measured, which represent the axes of the plant ecological strategy scheme LHS and wood density, are efficient in the discrimination of functional groups in the Brazilian semiarid. These groups relate to leaf phenology of woody species in this vegetation.