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1.
PLoS One ; 16(3): e0247478, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33690726

RESUMO

The Museo Nazionale della Scienza e della Tecnologia "Leonardo da Vinci" in Milan is exposing two pairs of canal lock gates, used to control the water flow in Milan canal system, whose design appears in the Leonardo's Codex Atlanticus. The wood present in the gates has been deeply characterised by mean of a multidisciplinary investigation involving i) DNA barcoding of wood fragments; ii) microbial community characterisation, and iii) chemical analyses. DNA barcoding revealed that two fragments of the gates belonged to wood species widely used in the middle age: Fagus sylvatica and Picea abies. The chemical characterisations were based on the use of ionic liquid as dissolving medium in order to analyse the entire cell wall material by means of Gel Permeation Chromatography (GPC) and 2D-NMR-HSQC techniques. This multidisciplinary analytical approach was able to highlight the complex nature of the degradation occurred during the gate operation (XVI-XVIII centuries): an intricate interplay between microbial populations (i.e. Shewanella), inorganic factors (i.e. iron from nails), physical factors and the lignocellulosic material.


Assuntos
Materiais de Construção/história , Código de Barras de DNA Taxonômico/métodos , Madeira/química , Madeira/classificação , Cromatografia em Gel , DNA de Plantas/genética , Fagus/classificação , Fagus/genética , História Antiga , Itália , Lignina/análise , Filogenia , Picea/classificação , Picea/genética , Madeira/genética
2.
Sci Rep ; 10(1): 13705, 2020 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-32792600

RESUMO

The aim of the study was to determine damage severity of wood-destroying insects on logs stored in forest depots. The Bevan damage classification (BDC) system, developed in 1987, was utilized to determine damage severity in log depots in 21 locations throughout seven provinces in Turkey. Pheromone traps were placed in those locations at the beginning of April in 2015 and 2016. Furthermore some stored wood within the log depots were checked and split into small pieces to collect insects that damage wood. The BDC system was used for the first time to measure the severity of insect damage in log depots. Twenty-eight families, 104 genera and 123 species were identified in this study. Based on the BDC system, the highest damage was found from the Cerambycidae and Buprestidae families. Arhopalus rusticus was determined as the insect responsible for the highest amount of damage with 8.8% severity rating in the pheromone-trapped insects group. When the stored wood material was considered, Hylotrupes bajulus was found to be the cause of the highest damage. The lowest damage values were among the predator insects (Cleridae, Trogossitidae, Cantharidae) and those feeding on fungi colonized on the wood (Mordellidae, Cerylonidae, Nitidulidae). Some other predator insects of the Tenebrionidae family (Uloma cypraea, Uloma culinaris, Menephilus cylindricus) and Elateridae family (Lacon punctatus, Ampedus sp.) exhibited relatively higher damage severity values since they had built tunnels and made holes in the stored wood material. When the environmental factors were considered, the Buprestidae family exhibited a very strong positive relationship (p < 0.005) with insect frequency distribution (r = 0.922), number of species (r = 0.879) and insect density (r = 0.942). Both families showed the highest number and frequency during July and August, highlighting the importance of insect control and management during these months.


Assuntos
Besouros/fisiologia , Controle de Insetos/métodos , Modelos Biológicos , Madeira/química , Madeira/classificação , Animais , Florestas , Turquia , Madeira/crescimento & desenvolvimento
3.
Environ Microbiol ; 22(11): 4702-4717, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32840945

RESUMO

Diverse communities of fungi and bacteria in deadwood mediate wood decay. While rates of decomposition vary greatly among woody species and spatially distinct habitats, the relative importance of these factors in structuring microbial communities and whether these shift over time remains largely unknown. We characterized fungal and bacterial diversity within pieces of deadwood that experienced 6.3-98.8% mass loss while decaying in common garden 'rotplots' in a temperate oak-hickory forest in the Ozark Highlands, MO, USA. Communities were isolated from 21 woody species that had been decomposing for 1-5 years in spatially distinct habitats at the landscape scale (top and bottom of watersheds) and within stems (top and bottom of stems). Microbial community structure varied more strongly with wood traits than with spatial locations, mirroring the relative role of these factors on decay rates on the same pieces of wood even after 5 years. Co-occurring fungal and bacterial communities persistently influenced one another independently from their shared environmental conditions. However, the relative influence of wood construction versus spatial locations differed between fungi and bacteria, suggesting that life history characteristics of these clades structure diversity differently across space and time in decomposing wood.


Assuntos
Microbiota/fisiologia , Madeira/microbiologia , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Carya/microbiologia , Florestas , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Interações Microbianas , Missouri , Quercus/microbiologia , Fatores de Tempo , Madeira/classificação
4.
Sci Rep ; 10(1): 4352, 2020 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-32152386

RESUMO

The wood adulteration is a common problem and under-studied aspect in the timber industry of Sri Lanka. Hence we conducted a survey to assess the status of timber adulteration and check the applicability of morphometric parameters and DNA barcoding to detect the adulterated timber sources. We interviewed the stakeholders of the timber industry to collect information regarding timber adulterations. We measured the morphometric parameters; wood density and sizes of the xylem elements of the standard and adulterant species. For DNA barcoding, DNA was extracted from the wood of the selected standard and adulterant species and subjected to PCR using the markers, matK-trnT and atpB-rbcL. The PCR products were subjected to DNA sequencing. According to the survey, 92.5% of patrons, 73.7% of manufacturers and 96.7% of carpenters said timber adulteration is taking place in the country. The respondents said that the standard timber species; Tectona grandis, Artocarpus heterophyllus, and Swietenia macrophylla, profoundly undergo adulteration in Sri Lanka. The morphometric parameters did not discriminate the adulterant species from the standard species. The DNA barcodes matK-trnT and atpB-rbcL provided unique polymorphic DNA sequences with specific lengths for each species permitting the precise establishment of species identity and enabling the accurate detection of timber adulterations.


Assuntos
Código de Barras de DNA Taxonômico , DNA de Plantas , Madeira/anatomia & histologia , Madeira/classificação , Madeira/genética , Filogenia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Especificidade da Espécie , Sri Lanka
5.
PLoS One ; 15(1): e0227008, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31940392

RESUMO

The appearance of the Linear Pottery Culture (LBK) on Poland territory initiated the process of neolithization in the area. However, as we will see in this article, this colonization took place later than previously thought. The stage, which in Poland is called as the early phase, actually corresponds only to the Fomborn/Ackovy stage of LBK, and the earliest dating currently indicates around 5350 BC. Due to the small number of sites from this phase excavated on a large scale in Poland, this stage of the culture's development is poorly known. The Gwozdziec Project is focused on the earliest stage of LBK settlement in south-eastern Poland. Excavation at the site was finished in 2018. Therefore, the article presents preliminary results of interdisciplinary analyzes, such as research on ceramics, flint production and use, and botanical remains. They point to various aspects of the economy of these early agricultural communities and significantly enrich the knowledge of this period in Central Europe. They also expose the chronological development of the oldest LBK development stage in Poland.


Assuntos
Agricultura , Arqueologia , Plantas/classificação , Antropologia Cultural , Cerâmica , Polônia , Madeira/análise , Madeira/classificação
6.
J Nat Med ; 74(1): 42-50, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31250369

RESUMO

Agarwood is a type of resinous wood found in the trunks of Aquilaria, Gonystylus, and Gyrinops species [1]. High-quality agarwood is extraordinarily expensive and therefore its source plant species have become depleted due to exploitation. In 2005, these species were added to Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora [1]. Because these wild agarwood resources have become depleted, commercial production of agarwood has long been a desirable goal. In addition, inauthentic agarwood is sometimes produced from non-agarwood species. Few reports have attempted to identify source species in order to distinguish genuine from false agarwood. In this study, DNA was extracted from putative agarwood samples collected from Japanese, Indonesian, Thai, and Vietnamese markets. The trnL-trnF region and matK gene were amplified from each sample by PCR to serve as DNA barcodes for identifying the plant species to which each sample belonged. One of the wood samples did not originate from a genuine agarwood species. Although some species were identified, sequence data for agarwood source species currently available in GenBank is insufficient to identify the species to which all of these putative agarwood samples belonged. Thus, positive identification of remaining samples will require further exploration.


Assuntos
Código de Barras de DNA Taxonômico/métodos , Thymelaeaceae/genética , Madeira/classificação , Sequência de Bases , Madeira/química , Madeira/genética
7.
Sci Rep ; 9(1): 13157, 2019 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-31511632

RESUMO

Germplasm resource collection and utilization are important in forestry species breeding. High-through sequencing technologies have been playing increasing roles in forestry breeding. In this study, specific-locus amplified fragment sequencing (SLAF-seq) was employed to analyze 149 masson pine (Pinus massoniana) accessions collected from Guangdong in China. A large number of 471,660 SNPs in the total collection were identified from 599,164 polymorphic SLAF tags. Population structure analysis showed that 149 masson pines could not be obviously divided into subpopulations. Two core sets, containing 29 masson pine accessions for increasing resin and wood yield respectively, were obtained from the total collection. Phenotypic analyses of five traits showed abundant variations, 25 suggestive and 9 significant SNPs were associated with the resin-yielding capacity (RYC') and volume of wood (VW) using EMMAX and FaST-LMM; 22 suggestive and 11 significant SNPs were associated with RYC' and VW using mrMLM and FASTmrMLM. Moreover, a large number of associated SNPs were detected in trait HT, DBH, RW and RYC using mrMLM, FASTmrMLM, FASTmrEMMA and ISIS EM-BLASSO. The core germplasm sets would be a valuable resource for masson pine improvement and breeding. In addition, the associated SNP markers would be meaningful for masson pine resource selection.


Assuntos
Estudo de Associação Genômica Ampla/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Pinus/genética , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas/genética , China , Fenótipo , Filogenia , Pinus/classificação , Melhoramento Vegetal/métodos , Especificidade da Espécie , Madeira/classificação , Madeira/genética
8.
PLoS One ; 14(8): e0220762, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31404108

RESUMO

The anatomical structure of wood is complex and contains considerable information about its specific species, physical properties, growth environment, and other factors. While conventional wood anatomy has been established by systematizing the xylem anatomical features, which enables wood identification generally up to genus level, it is difficult to describe all the information comprehensively. This study apply two computer vision approaches to optical micrographs: the scale-invariant feature transform algorithm and connected-component labelling. They extract the shape and pore size information, respectively, statistically from the whole micrographs. Both approaches enable the efficient detection of specific features of 18 species from the family Fagaceae. Although the methods ignore the positional information, which is important for the conventional wood anatomy, the simple information on the shape or size of the elements is enough to describe the species-specificity of wood. In addition, according to the dendrograms calculated from the numerical distances of the features, the closeness of some taxonomic groups is inconsistent with the types of porosity, which is one of the typical classification systems for wood anatomy, but consistent with the evolution based on molecular phylogeny; for example, ring-porous group Cerris and radial-porous group Ilex are nested in the same cluster. We analyse which part of the wood structure gave the taxon-specific information, indicating that the latewood zone of group Cerris is similar to the whole zone of group Ilex. Computer vision approaches provide statistical information that uncovers new aspects of wood anatomy that have been overlooked by conventional visual inspection.


Assuntos
Fagaceae/anatomia & histologia , Madeira/anatomia & histologia , Algoritmos , Evolução Biológica , Fagaceae/classificação , Processamento de Imagem Assistida por Computador , Quercus/anatomia & histologia , Quercus/classificação , Madeira/classificação
9.
PLoS One ; 14(7): e0219917, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31344141

RESUMO

Fraud and misrepresentation in forest products supply chains is often associated with illegal logging, but the extent of fraud in the U.S. forest products market, and the availability of forensic expertise to detect it, is unknown. We used forensic wood anatomy to test 183 specimens from 73 consumer products acquired from major U.S. retailers, surveyed U.S. experts regarding their forensic wood anatomy capacity, and conducted a proficiency-testing program of those experts. 62% of tested products (45 of 73) had one or more type of fraudulent or misrepresented claim. Survey respondents reported a total capacity of 830 wood specimens per year, and participants' identification accuracy ranged from 6% to 92%. Given the extent of fraud and misrepresentation, U.S. wood forensic wood anatomy capacity does not scale with the need for such expertise. We call for increased training in forensic wood anatomy and its broader application in forest products supply chains to eliminate fraud and combat illegal logging.


Assuntos
Ciências Forenses/métodos , Madeira/anatomia & histologia , Ciências Forenses/educação , Florestas , Fraude , Marketing , Estados Unidos , Madeira/classificação
10.
Plant J ; 100(1): 83-100, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31166032

RESUMO

Norway spruce is a boreal forest tree species of significant ecological and economic importance. Hence there is a strong imperative to dissect the genetics underlying important wood quality traits in the species. We performed a functional genome-wide association study (GWAS) of 17 wood traits in Norway spruce using 178 101 single nucleotide polymorphisms (SNPs) generated from exome genotyping of 517 mother trees. The wood traits were defined using functional modelling of wood properties across annual growth rings. We applied a Least Absolute Shrinkage and Selection Operator (LASSO-based) association mapping method using a functional multilocus mapping approach that utilizes latent traits, with a stability selection probability method as the hypothesis testing approach to determine a significant quantitative trait locus. The analysis provided 52 significant SNPs from 39 candidate genes, including genes previously implicated in wood formation and tree growth in spruce and other species. Our study represents a multilocus GWAS for complex wood traits in Norway spruce. The results advance our understanding of the genetics influencing wood traits and identifies candidate genes for future functional studies.


Assuntos
Genes de Plantas/genética , Estudo de Associação Genômica Ampla/métodos , Picea/genética , Locos de Características Quantitativas/genética , Madeira/genética , Algoritmos , Genômica/métodos , Genótipo , Desequilíbrio de Ligação , Noruega , Fenótipo , Picea/classificação , Polimorfismo de Nucleotídeo Único , Madeira/classificação
11.
Molecules ; 24(4)2019 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-30813336

RESUMO

Pterocarpus santalinus and Pterocarpus tincorius are commonly used traded timber species of the genus Pterocarpus. P. santalinus has been listed in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). As a non-CITES species, P. tincorius is also indiscriminately labeled as P. santalinus due to the similar macroscopic and microscopic features with P. santalinus. In order to understand the molecular discrimination between these easily confused species, xylarium heartwoods of these two species were extracted by three different kinds of solvents and analyzed using gas chromatography⁻mass spectrometry (GC-MS). Multivariate analyses were also applied for the selection of marker compounds that are distinctive between P. santalinus and P. tincorius. A total of twenty volatile compounds were detected and tentatively identified in three kinds of extracts, and these compounds included alcohols, stilbenoids, esters, aromatic hydrocarbons, ketones, miscellaneous, phenols, and flavonoids. GC-MS analyses also revealed that extraction solvents including ethanol and water (EW), ethyl acetate (EA), and benzene⁻ethanol (BE) gave the best chemotaxonomical discrimination in the chemical components and relative contents of the two Pterocarpus species. After chemometric analyses, EW displayed higher predictive accuracy (100%) than those of EA extract (83.33%) and BE extract (83.33%). Furthermore, spathulenol (17.58 min) and pterostilbene (23.65 min) were elucidated as the critical compounds for the separation of the EW extracts of P. santalinus and P. tinctorius. Thus, a protocol of GC-MS and multivariate analyses was developed to use for successfully distinguishing P. santalinus from P. tinctorius.


Assuntos
Pterocarpus/classificação , Compostos Orgânicos Voláteis/análise , Madeira/química , Espécies em Perigo de Extinção , Flavonoides/análise , Cromatografia Gasosa-Espectrometria de Massas , Fenóis/análise , Pterocarpus/química , Solventes/química , Madeira/classificação
12.
Neotrop Entomol ; 48(4): 527-537, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30756330

RESUMO

We tested whether hardness or different wood carbon densities, considered as the concentration of carbon structural compounds, influence functional feeding groups and species richness of aquatic insects in a tropical stream. We expected that harder woods would harbor aquatic insect communities with species richness and functional food group profile different from softwoods. We also expected that collector-gatherers and collector-filterers will be more abundant in softwood because harder woods are less substrate suitable for biofilm production. Aquatic insects associated with the following plants were analyzed: Gomidesia lindeniana with high-density, Psychotria grandis with medium-density, and Meriania leucantha with low-density wood. Diptera and Ephemeroptera were the most abundant groups sampled in the woods. Psychotria grandis shows higher concentrations of lignin, cellulose, and hemicellulose, followed by G. lindeniana and M. leucantha. Breakdown rates are different among plant species with M. leucantha having four times highest breakdown rates and on average three more species in the species richness value. We did not find significant differences in the composition of insect species associated with the plants. We found evidence that the richness and functional organization of aquatic insect communities were mostly related to the breakdown rates and lignin amount of the woods. Plants that decompose faster on average have three more species and two more insect functional groups. Our findings suggest that the loss of high carbon density trees in tropical forests can affect aquatic biodiversity.


Assuntos
Biodiversidade , Insetos/classificação , Floresta Úmida , Rios , Madeira/classificação , Animais , Celulose/química , Cuba , Lignina/química , Polissacarídeos/química
13.
Sci Data ; 6: 180303, 2019 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-30620340

RESUMO

The quantity and condition of downed dead wood (DDW) is emerging as a major factor governing forest ecosystem processes such as carbon cycling, fire behavior, and tree regeneration. Despite this, systematic inventories of DDW are sparse if not absent across major forest biomes. The Forest Inventory and Analysis program of the United States (US) Forest Service has conducted an annual DDW inventory on all coterminous US forest land since 2002 (~1 plot per 38,850 ha), with a sample intensification occurring since 2012 (~1 plot per 19,425 ha). The data are organized according to DDW components and by sampling information which can all be linked to a multitude of auxiliary information in the national database. As the sampling of DDW is conducted using field efficient line-intersect approaches, several assumptions are adopted during population estimation that serve to identify critical knowledge gaps. The plot- and population-level DDW datasets and estimates provide the first insights into an understudied but critical ecosystem component of temperate forests of North America with global application.


Assuntos
Florestas , Madeira/classificação , Ecossistema , Estados Unidos
14.
FEMS Microbiol Ecol ; 95(3)2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30668687

RESUMO

Despite the increasing number of studies on deadwood, we still have limited knowledge of its dynamics. The aim of this study was to examine the effect of deadwood on the biochemical properties of soil and stabilisation of soil organic matter (SOM). The investigation was carried out in the Czarna Rózga Reserve in Central Poland. The logs of four tree species at different stages of decomposition (III, IV and V) were selected for the analysis. Three replicate logs were sampled for each combination of decay classes, and the soil samples were collected from directly under the logs and from 1 m away from the logs. In this way, changes to the chemical and biochemical properties of the wood were determined. The SOM was physically fractioned. As the rate of deadwood decomposition increases, its biochemical activity increases and its chemical properties change. The biochemical activity, especially the soil's enzyme activity, was stimulated under highly decayed deadwood. The effects of deadwood are visible in SOM fractions, particularly in the content of the light fraction of SOM.


Assuntos
Solo/química , Madeira/química , Madeira/classificação , Substâncias Húmicas/análise , Polônia , Árvores/química , Árvores/classificação
15.
Sci Total Environ ; 655: 720-729, 2019 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-30476852

RESUMO

The discharge from food production greenhouses (greenhouse effluent) contains high nutrient and salt concentrations, which, if directly released, can have adverse effects on the environment. Wood-chip bioreactors are increasingly popular passive water treatment systems favoured for their economical denitrification in treating agricultural field tile drainage. Microbial communities are central to denitrification; however little is known about the maturation of microbial communities in wood-chip bioreactors treating greenhouse effluents. In this study, multiple subsurface flow wood-chip bioreactors, each vegetated with a different plant species, together with an unplanted unit, received synthetic greenhouse effluent with elevated nitrate concentrations. The hybrid bioreactors were operated for over 2 years, during which time water samples were collected from the inlet, outlet and within the reactors. The increasing denitrification rate in the bioreactor planted with Typha angustifolia (narrowleaf cattail) correlated with increasing microbial activity and metabolic richness, measured by the carbon utilization patterns in Biolog® EcoPlates. Increased denitrifying gene (nirS) copies (determined by quantitative polymerase chain reaction, qPCR), and near-complete nitrate removal were observed in the T. angustifolia and unplanted reactors after 16 and 23 months of operation respectively. The findings suggested that an acclimation period of at least one year can be expected in unseeded bioreactors planted with T. angustifolia, while bioreactors without vegetation may require a longer time to maximize their denitrification capacity. These results are important for the design and operation of wood-chip bioreactors, which are expected to be more commonly applied in the future.


Assuntos
Reatores Biológicos/microbiologia , Desnitrificação , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/microbiologia , Purificação da Água/métodos , Madeira/metabolismo , Biodegradação Ambiental , Desnitrificação/genética , Microbiota/fisiologia , Nitratos/isolamento & purificação , Nitratos/metabolismo , Oxirredução , Águas Residuárias/química , Madeira/classificação
16.
J Sci Food Agric ; 99(1): 315-324, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-29876929

RESUMO

BACKGROUND: The most frequent renewal of barrels of different origins and species is a current trend, but this demand does not match the current availability of wood. An alternative could be the use of Quercus humboldtii wood. However, there is little information about its composition. Because of this, the aim was to study low-molecular-weight phenols (LMWP), ellagitannins and volatile compounds in untoasted and toasted Q. humboldtii oak, and compare these with the species traditionally used in cooperage: Q. petraea (French and Romanian) and Q. alba (American). RESULTS: The LMWPs in Q. humboldtii were comparable to those in Q. petraea and Q. alba. Ellagitannin composition in Q. humboldtii was similar to that in Q. alba. The toasting process improved volatile composition, mainly in Q. humboldtii, presenting the highest concentration of several volatile compounds. CONCLUSION: The results indicate that Q. humboldtii could be considered suitable for aging wine, although it is necessary to continue the study of this wood species to confirm its potential use in oenology. © 2018 Society of Chemical Industry.


Assuntos
Embalagem de Alimentos/instrumentação , Fenóis/química , Quercus/química , Compostos Orgânicos Voláteis/química , Madeira/química , Temperatura Alta , Peso Molecular , Quercus/classificação , Vinho/análise , Madeira/classificação
17.
Molecules ; 25(1)2019 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-31905645

RESUMO

We report the manufacturing and characterization of poly (butylene succinate) (PBS) and micro cellulose (MCC) woody-like composites. These composites can be applied as a sustainable woody-like composite alternative to conventional fossil polymer-based wood-plastic composites (WPC). The PBS/MCC composites were prepared by using a melt blending of 70 wt% of MCC processed from bleached softwood. MCC was modified to enhance dispersion and compatibility by way of carbodiimide (CDI), polyhydroxy amides (PHA), alkyl ester (EST), (3-Aminopropyl) trimethoxysilane (APTMS), maleic acid anhydride (MAH), and polymeric diphenylmethane diisocyanate (PMDI). The addition of filler into PBS led to a 4.5-fold improvement of Young's modulus E for the MCC composite, in comparison to neat PBS. The 1.6-fold increase of E was obtained for CDI modified composition in comparison to the unmodified MCC composite. At room temperature, the storage modulus E' was found to improve by almost 4-fold for the APTMS composite. The EST composite showed a pronounced enhancement in viscoelasticity properties due to the introduction of flexible long alkyl chains in comparison to other compositions. The glass transition temperature was directly affected by the composition and its value was -15 °C for PBS, -30 °C for EST, and -10 °C for MAH composites. FTIR indicated the generation of strong bonding between the polymer and cellulose components in the composite. Scanning electron microscopy analysis evidenced the agglomeration of the MCC in the PBS/MCC composites. PMDI, APTMS, and CDI composites were characterized by the uniform dispersion of MCC particles and a decrease of polymer crystallinity. MCC chemical modification induced the enhancement of the thermal stability of MCC composites.


Assuntos
Butileno Glicóis/química , Celulose/química , Polímeros/química , Butileno Glicóis/síntese química , Módulo de Elasticidade , Polímeros/síntese química , Resistência à Tração , Madeira/classificação
18.
Environ Microbiol ; 20(10): 3744-3756, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30109768

RESUMO

Deadwood represents an important structural component of forest ecosystems, where it provides diverse niches for saproxylic biota. Although wood-inhabiting prokaryotes are involved in its degradation, knowledge about their diversity and the drivers of community structure is scarce. To explore the effect of deadwood substrate on microbial distribution, the present study focuses on the microbial communities of deadwood logs from 13 different tree species investigated using an amplicon based deep-sequencing analysis. Sapwood and heartwood communities were analysed separately and linked to various relevant wood physico-chemical parameters. Overall, Proteobacteria, Acidobacteria and Actinobacteria represented the most dominant phyla. Microbial OTU richness and community structure differed significantly between tree species and between sapwood and heartwood. These differences were more pronounced for heartwood than for sapwood. The pH value and water content were the most important drivers in both wood compartments. Overall, investigating numerous tree species and two compartments provided a remarkably comprehensive view of microbial diversity in deadwood.


Assuntos
Bactérias/metabolismo , Árvores/microbiologia , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Florestas , Microbiota , Filogenia , Árvores/química , Árvores/classificação , Madeira/química , Madeira/classificação , Madeira/microbiologia
19.
J Ethnobiol Ethnomed ; 14(1): 21, 2018 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-29558963

RESUMO

BACKGROUND: Atakora mountains in Benin are a unique but fragile ecosystem, harboring many endemic plant species. The ecosystem is undergoing degradation, and the woody vegetation is dramatically declining due to high anthropogenic actions and recurrent drought. This study aimed to (i) assess the diversity of threatened woody species and (ii) identify their potential substitutes in the three regions of the Atakora mountains namely East Atakora, Central Atakora, and West Atakora. METHODS: The data were collected during expeditions on surveyed localities through semi-structured individual interviews. Free-listing was used to record threatened woody species and which were important and why. Alpha-diversity indices were used to assess diversity of threatened and important threatened woody species. A correspondence analysis was used to determine the reason supporting their importance. Differences in species composition were assessed using analysis of similarities. A number of potential substitutes were compared among species using generalized linear models. RESULTS: A total of 117 woody species (37 families and 92 genera) were identified. The most prominent families were Fabaceae (19.66%), Combretaceae (12.82%), and Moraceae (10.26%), and the richest genera were Ficus (10 species), Combretum (6), and Terminalia (5). Most threatened species differed across regions (East Atakora, Central Atakora, and West Atakora) and included Afzelia africana, Anogeissus leiocarpa, Borassus aethiopum, Diospyros mespiliformis, Khaya senegalensis, Milicia excelsa, and Pterocarpus erinaceus. Most socio-economically important species (K. senegalensis, Parkia biglobosa, Vitellaria paradoxa, and V. doniana) were used mainly for food, timber, and fuelwood purposes. Old and adult people, and Dendi and Fulfulde sociolinguistic groups had greater knowledge of threatened woody plant species. High intercultural differentiations in species composition were detected between Bariba-Berba and Bariba-Natimba. Knowledge of substitutes also differed across regions with P. erinaceus, Isoberlinia spp., and A. africana being the most cited substitutes. CONCLUSION: Basic data was provided here to inform decision and guide efficient management of woody resources. There was evidence that immediate conservation measures are required for some high economic value woody taxa which were critically threatened. Ex-situ conservation of these species while promoting their integration into agroforestry-based systems were recommended. Besides, community-based management programs and community-led initiatives involving knowledgeable people from different horizons will lead to a long-lasting conservation of these threatened resources.


Assuntos
Biodiversidade , Ecossistema , Espécies em Perigo de Extinção , Madeira , Adulto , Idoso , Benin , Conservação dos Recursos Naturais , Feminino , Humanos , Conhecimento , Masculino , Pessoa de Meia-Idade , Madeira/classificação
20.
Nature ; 554(7691): 224-228, 2018 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-29420466

RESUMO

Synthetic structural materials with exceptional mechanical performance suffer from either large weight and adverse environmental impact (for example, steels and alloys) or complex manufacturing processes and thus high cost (for example, polymer-based and biomimetic composites). Natural wood is a low-cost and abundant material and has been used for millennia as a structural material for building and furniture construction. However, the mechanical performance of natural wood (its strength and toughness) is unsatisfactory for many advanced engineering structures and applications. Pre-treatment with steam, heat, ammonia or cold rolling followed by densification has led to the enhanced mechanical performance of natural wood. However, the existing methods result in incomplete densification and lack dimensional stability, particularly in response to humid environments, and wood treated in these ways can expand and weaken. Here we report a simple and effective strategy to transform bulk natural wood directly into a high-performance structural material with a more than tenfold increase in strength, toughness and ballistic resistance and with greater dimensional stability. Our two-step process involves the partial removal of lignin and hemicellulose from the natural wood via a boiling process in an aqueous mixture of NaOH and Na2SO3 followed by hot-pressing, leading to the total collapse of cell walls and the complete densification of the natural wood with highly aligned cellulose nanofibres. This strategy is shown to be universally effective for various species of wood. Our processed wood has a specific strength higher than that of most structural metals and alloys, making it a low-cost, high-performance, lightweight alternative.


Assuntos
Madeira/química , Ligas/química , Parede Celular/química , Celulose/química , Temperatura Alta , Lignina/química , Lignina/isolamento & purificação , Metais/química , Peso Molecular , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Hidróxido de Sódio/química , Sulfitos/química , Resistência à Tração , Madeira/classificação
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