Precious Wood Research Articles

Deep Learning Method of Precious Wood Image Classification Based on Microscopic Computed Tomography

Correctly identifying precious wood species is crucial for import and export trade and furniture material identification. This study utilizes nondestructive testing (Microscopic Computed Tomography, Micro-CT) to capture microscopic images of the transverse, radial, and tangential sections of 24 precious wood species, creating a comprehensive dataset. The SLConNet deep learning model is developed, enhancing recognition accuracy through multi-scale convolution and an improved residual block structure. The experiment results show that the classification accuracy of the transverse, radial and tangential sections is 98.72, 96.75 and 95.36 % respectively when the gain value is 0.8. The model outperforms traditional models like Alexnet, ResNet50, Inception-V3, and Xception. This research highlights the efficiency of nondestructive testing in obtaining a large number of microscopic wood images, compared to traditional anatomical methods. The SLConNet model showcases high accuracy in precision, recall, and specificity, suggesting its potential for widespread applications in wood classification.

Measurement and Validation of Market Power in China’s Log Import Trade—Empirical Analysis Based on PTM Model and AIDS Model

China is the world’s largest importer of logs, possessing the scale to exert significant influence in the international market. This paper uses a fixed-effect variable coefficient Pricing-to-Market panel model to measure China’s market power in log import trade. It also utilizes the Almost Ideal Demand System model from an elasticity perspective to explore the market behavior characteristics of various source countries in China’s log import trade, thereby validating the mechanism of market power. The results indicate that: ① China’s main trading partners can be categorized into four groups according to their market power in the log import trade. Specifically, China holds superlative market power in log imports from Indonesia, Malaysia, and Myanmar; holds strong market power in log imports from Russia, the Democratic Republic of the Congo, and Mozambique; holds weak market power in log imports from Papua New Guinea, Equatorial Guinea, France, Germany, Australia, and New Zealand; and holds no market power in Japan, Cameroon, and the United States. ② As China’s expenditure on log imports increases, there is a tendency to purchase high-quality precious wood and a greater concern for the legality of market transactions. Consequently, China is anticipated to augment its imports from source countries with no or weak market power. ③ The simple price elasticity of log imports from each source country is negative. Source countries with stronger market power tend to increase prices to achieve higher total revenue, while those with weaker market power are more inclined to lower prices to achieve the same. ④ Log products from various source countries are complementary in the Chinese market, indicating that China’s substantial demand for logs relies on the simultaneous supply from multiple countries and diverse wood types. Based on the existence or absence of market power in China’s log import trade, this paper provides targeted insights into enhancing international market power and reducing trade losses.

Improvement of UV resistance and mechanism in polypropylene wax on wood surface through maleic anhydride and β-nucleating agent modification

In China, beeswax is commonly used to protect hardwood surfaces through hot waxing, and is widely utilized in wood furniture and buildings. However, beeswax, with its low melting point and high cost, is prone to being destroyed and falling off, and has a short-term protective effect on wood under ultraviolet (UV) light. Polypropylene wax (PPW), with its low cost and high melting point, holds potential for application in wood protection. The introduction of maleic anhydride enhanced the combination of PPW and wood, resulting in excellent surface properties. Additionally, the β-nucleating agent (WBG-II) induced PPW to form β crystal structure, further enhancing the UV barrier property of the wax coating. After UV irradiation, the surface properties of the hot-waxed wood using the modified polypropylene wax exhibited minimal changes, including color, adhesion, hydrophobicity, and surface roughness. The chemical structure, crystalline structure, and surface morphology were analyzed by FTIR, XRD, and SEM to reveal the photodegradation mechanism of the surface wax coating. The results demonstrated that the co-modification of polypropylene wax by maleic anhydride and WBG-II has a positive effect on the long-term protection of wood substrate, providing a reference for wood protection, particularly for dark and precious wood, and helping to reduce deforestation.

Enhancing flame retardancy and antibacterial properties of wood veneer by promoting crosslinking in metal-organic framework structures

Decorative veneer, rotary cut from wood, serving as the outermost layer of decorative plates and is exposed to potential risks of fire hazards and bacterial growth. In this study, following the principle of eco-friendly and cost-effective, the polyamino polyether methylene phosphonate (PAPEMP) and magnesium chloride (MgCl2) were sequentially impregnated into the veneer, and then the alkaline environment was employed to facilitate the complexation, leading to the formation of cross-linked chains within the porous wood structure. Consequently, the modified wood veneer, endowed with exceptional flame retardancy, smoke suppression, antibacterial properties, and good wettability was successfully achieved. Through optimization in an alkaline environment, the modified decorative veneer exhibits a remarkable increase in limiting oxygen index from 19.7% in the pure veneer to 36.9%, coupled with a significant reduction of 19.38% in total heat release and 65.22% in total smoke release compared to the pure veneer. Additionally, the peak mass loss rate (PLMR) of the modified veneer was 66.41% lower than that of the pure veneer, and the char residue increased to 46.1%, representing a 149.19% improvement over the pure veneer. Compared with pure veneer, the wettability of modified veneer increased by 37.93%. Additionally, the tensile strength parallel to the grain of the modified veneer was enhanced by 22.09% compared to the veneer without NaOH solution treatment, and exhibits strong inhibitory effects on colony reproduction. The developed flame-retardant and antibacterial treatment processes for decorative veneers offer a novel and environmentally friendly method for utilizing precious tree veneers, suitable for a variety of precious woods, and successfully applied to decorative wooden doors and wooden fire-resistant doors.

An Environmentally Friendly Alternative Method of Producing Religious Images for Philippine Holy Week Tableaus

This paper presents a proposed process of making Philippine Holy Week sacred images from clay, plaster, and paper fiber instead of the more precious wood from the country's shrinking forests. This paper theoretically established the durability of the product and environmental soundness of this alternative process compared to the traditional wood carving or the more recent resin casting by thoroughly describing this alternative process by understanding the notion of durability based on the traditionally preferred woods among santeros, by understanding the conservation status of these preferred woods, and by undertaking comparative calculations of the environmental impacts of the productions of the three current alternatives. This paper is significant because it proposes a sustainable way of assuring the continued existence of the Filipino cultural tradition of making and presenting Holy Week images.

ENFOQUES GENÓMICOS Y TRANSCRIPTÓMICOS PARA ESTUDIAR ÁRBOLES MADERABLES: PERSPECTIVAS PARA EL ESTUDIO DE CEDRO ROJO (Cedrela odorata L.)

<p><strong>Introduction</strong>: The high-throughput genomic and transcriptomic approach has been developed and implemented to address the main challenges that the timber forestry sector faces, such as population growth, climate change, deforestation and the loss of forest ecosystem services. <strong>Objective:</strong> To carry out a bibliographic review focused on the genomes and transcriptomes of timber trees reported in the databases, with special attention to red cedar (<em>Cedrela odorata</em> L.), due to its importance as precious wood in Mexico. <strong>Methodology:</strong> A literature review was carried out, directed at studying timber trees with genomic and transcriptomic strategies in different databases such as Pubmed, Scopus, Google Scholar, ScienceDirect, Wiley Online Library, MDPI and Scielo to identify the timber species that have been reported genomes and transcriptomes. The structure of the review was the genomics of timber trees, the transcriptomics of wood, and the potential species for study due to their importance and finally, the databases for consultation. Subsequently, a bibliometric study was carried out with the bibliometrix library in R Studio. <strong>Main results</strong>: The first genome to be assembled at the chromosome level was the black cottonwood. Among the timber trees, the genomes of black cottonwood, desert poplar, eucalyptus and oak with a length of 392, 496, 691 and 789 Mb have been reported. Through study of the transcriptome, it has been possible to identify genes related to formation of the wood in a hybrid poplar (<em>Populus alba</em> L.<em> × P. glandulosa</em>) and <em>P. tremula</em> L. and with drought tolerance in <em>Pinus massoniana</em> and <em>Pinus pinaster</em> Aiton. In red cedar (<em>Cedrela odorata</em> L.), the transcriptome was obtained by sequencing a single leaf, identifying 52,181 gene models. In the NCBI, EMBL-EBI, TreeGenes, PLAZA databases and the hardwood genomics website it is possible to find information related to the genomics and transcriptomics of timber species. <strong>Implications:</strong> More research is required in omics in timber, particularly in red cedar, since the search on these topics yielded little information. <strong>Conclusion</strong>: Through the bibliographic review in databases, the timber trees that have a described genome and transcriptome were identified. This information can be used for the assembly and annotation of new genomes, identification of genes and molecular markers, among other applications.</p>

Morphological and Anatomical Characteristics of Taxus chinensis (Pilg.) Rehder in Thanh Hoa Province, Vietnam

The Taxus chinensis (Pilg.) Rehder belongs to the Taxaceae family, confer plants and is a rare and precious tree species of Vietnam which was recognized for its use value. The most of them are distributed in the high mountains of Vietnam. The resource values of this species were found as medicine, precious wood and an ornamental. So, looking back to the long history of use as well as overall research on species of the Taxus L. genus, the up-to-date reporting on Taxus chinensis is relatively much less extensive. These studies are an effort to understand the anatomical delimitation of Taxus chinensis (Pilg.) Rehder in a better way and morphological characteristic with updated is provided. The comparative morphological and anatomical research method were used, Taxus chinensis has dominent characteristic with winter bud scales, gather into a cone shape, early deciduous; leaves linear, thick textured; pale to white at abaxially because of the thick stomata bands.

Study on the Discoloration Mechanism of Eucalyptus Wood during Thermal Treatment in Different Media

Chromophore structures in wood are the core elements for regulating wood color. Thermal treatment can regulate the color of wood, thus increasing its added value. In this study, conventional thermal treatment was used to regulate the color of Eucalyptus, in order to make its color close to the precious wood species Burma padauk. The color change in Eucalyptus wood was analyzed using the chromaticity index and UV-Vis. The chromophore structures in the treated wood and their discoloration mechanisms were characterized via FTIR, XPS, NMR, etc. The results showed that the color of eucalyptus could be regulated via thermal treatment to become more similar to the color of Burma padauk under both saturated steam and hot air. The treated wood showed a color difference in the 400~500 nm region in spectral absorption. The changes in the chromophore structures of wood were accompanied by the degradation of hemicelluloses. Meanwhile, demethoxylation occurred in the syringyl structure G of lignin, which led to the polymerization of lignin and decreased the lightness value of wood. Moreover, the number of conjugated structures in the chromophore groups increased, which caused the color of the wood to tend toward red. This study provides a reference for the color regulation of wood, and the mechanisms are also discussed.

A DNA barcode reference library for CITES listed Malagasy Dalbergia species.

On Madagascar, the illegal and unsustainable exploitation and illegal international trade of Dalbergia (rosewood) precious woods remain a serious conservation problem. Members of this genus are at high risk of extinction as a consequence of logging, mining, and slash and burn agriculture. Morphological identification of these Malagasy species is difficult in the absence of flowers and fruits, especially in the case of cut trees, sawn wood, and finished product. In this study, we use molecular barcoding to identify the Dalbergia species with the intent to contribute to the control of their illegal trade. Thirty-six Dalbergia samples representing 12 Malagasy species of which 11 have high commercial value, were collected to test the efficacy of a region of the plastid genome (rbcL) and a nuclear-transcribed ITS for barcoding. These widely used markers, as well as DNA barcoding gaps, "best match" and "best close match" approaches, and the neighbor-joining method were employed. All samples were amplified and sequenced using the two markers. Using a single locus, the "best match" and "best close match" approaches revealed that ITS has high discriminatory power within the tested Malagasy species. The combination of rbcL + ITS revealed 100% species discrimination. This study confirms that ITS alone and in combination with chloroplast barcode rbcL allow non-ambiguous identification for the 12 species studied. The results contribute to the development of DNA barcoding as a useful tool to identify Malagasy Dalbergia and suggest that the approach developed should be expanded to all 56 potentially exploited species in reference to international CITES requirements and the sustainable management of valuable resources.

Intelligent color matching model for wood dyeing using Genetic Algorithm and Extreme learning machine

Wood dyeing technology is of great significance to improve the utilization rate of inferior wood resources. The challenge to imitating precious wood species by inferior wood is to quickly and accurately obtain the dyeing formula of precious wood species. This study uses Genetic Algorithm (GA) to optimize Extreme learning machine (ELM), and then a predictive model based on GA-ELM is proposed for predicting the dyeing formula of precious wood species. The sum of the relative deviations of the three dyes between the predicted formula and the actual formula, that is, the relative deviation of the formula, is calculated to evaluate the model’s prediction accuracy. The simulation results show that the average relative deviations of the formula predicted by Back Propagation (BP) neural network, Radial Basis Function (RBF) neural network, ELM, and GA-ELM are 0.808, 0.717, 0.708, and 0.262. The prediction deviation of the GA-ELM is much smaller than that of other traditional neural networks, which can achieve good results in wood production.

Comparative Analysis of Chloroplast Genome Structure and Phylogenetic Relationships Among Six Taxa Within the Genus Catalpa (Bignoniaceae)

Species within the Genus Catalpa are mostly semievergreen or deciduous trees with opposite or whorled leaves. C. bungei, C. fargesii f. duclouxii and C. fargesii are sources of traditional precious wood in China, known as the “kings of wood”. Due to a lack of phenotypic and molecular studies and insufficient sequence information, intraspecific morphological differences, common DNA barcodes and partial sequence fragments cannot clearly reveal the phylogenetic or intraspecific relationships within Catalpa. Therefore, we sequenced the complete chloroplast genomes of six taxa of the genus Catalpa and analyzed their basic structure and evolutionary relationships. The chloroplast genome of Catalpa shows a typical tetrad structure with a total length ranging from 157,765 bp (C. fargesii) to 158,355 bp (C. ovata). The length of the large single-copy (LSC) region ranges from 84,599 bp (C. fargesii) to 85,004 bp (C. ovata), that of the small single-copy (SSC) region ranges from 12,662 bp (C. fargesii) to 12,675 bp (C. ovata), and that of the inverted repeat (IR) regions ranges from 30,252 bp (C. fargesii) to 30,338 bp (C. ovata). The GC content of the six chloroplast genomes were 38.1%. In total, 113 unique genes were detected, and there were 19 genes in IR regions. The 113 genes included 79 protein-coding genes, 30 tRNA genes and four rRNA genes. Five hypervariable regions (trnH-psbA, rps2-rpoC2, rpl22, ycf15-trnl-CAA and rps15) were identified by analyzing chloroplast nucleotide polymorphisms, which might be serve as potential DNA barcodes for the species. Comparative analysis showed that single nucleotide polymorphisms (SNPs) and simple sequence repeats (SSRs) were highly diverse in the six species. Codon usage patterns were highly similar among the taxa included in the present study. In addition to the stop codons, all codons showed a preference for ending in A or T. Phylogenetic analysis of the entire chloroplast genome showed that all taxa within the genus Catalpa formed a monophyletic group, clearly reflecting the relationships within the genus. This study provides information on the chloroplast genome sequence, structural variation, codon bias and phylogeny of Catalpa, which will facilitate future research efforts.

Stable Isotope Ratio Analysis for the Comparison of Timber From Two Forest Concessions in Gabon

Consumers are becoming increasingly aware of the environmental impacts caused by deforestation and illegal logging and there is an increasing demand for supply chain transparency and traceability of wood products. Many importing and exporting nations have implemented regulations which aim to control the origin and species of traded timbers of high ecological importance and economic value. However, despite growing interest in method development for timber authentication purposes, many studies have been limited by insufficient numbers of authentic timber reference samples. Our aim was to address the differences in stable isotope ratio profile of bulk, homogenized wood samples collected from living or recently felled trees in two FSC concessions in Gabon, which are approximately 240 km apart, for the purposes of origin classification and protecting valuable forest commodities. Forty-seven timber samples comprising 10 genera of tropical trees were obtained using a Pickering Punch sampling device or chainsaw from two forest concessions in Gabon (Precious Woods Group and Compagnie des Bois du Gabon) during July 2019. Samples were subject to δ18O, δ2H, δ13C, δ15N, and δ34S stable isotope analysis using elemental analysis-isotope ratio mass spectrometry (EA-IRMS). Results show that significant differences are evident in the stable isotope ratios of Aucoumea klaineana between Precious Woods Group and Compagnie des Bois du Gabon forest concessions. Relationships are evident between climatic and geological variables and the stable isotope ratios of the samples suggesting that further degrees of origin classification may be achievable in Gabon. For other species, insufficient numbers meant the possibility to determine discriminating factors between the two concessions was limited though data from these samples may prove useful to contribute to the understanding of stable isotope variability in tropical timber. The data presented establish a basis for evaluating origin claims of forest products and timber from the Compagnie des Bois du Gabon and Precious Woods Group concessions and lay a foundation for future development of timber tracking technologies in Gabon. The technique can be used for purposes of due diligence or forensic investigation by law enforcement as part of demand-side regulations such as the EU Timber Regulation, Illegal Logging Prevention Act, or the Lacey Act.

Research on Rosewood Micro Image Classification Method Based on Feature Fusion and ELM

Rosewood is a kind of high-quality and precious wood in China. The correct identification of rosewood species is of great significance to the import and export trade and species identification of furniture materials. In this paper, micro CT was used to obtain the micro images of cross sections, radial sections and tangential sections of 24 kinds of rosewood, and the data sets were constructed. PCA method was used to reduce the dimension of four features including logical binary pattern, local configuration pattern, rotation invariant LBP, uniform LBP. These four features and one feature not reducing dimension (rotation invariant uniform LBP) was fused with Gray Level CoOccurrence Matrix and Tamura features, respectively, a total of five fused features <i>LBP</i>+<i>GLCM</i>+<i>Tamura</i>, <i>LCP</i> +<i>GLCM</i>+<i>Tamura</i>, <img src="https://www.techscience.com/ueditor/files/jrm1.png" height="20px">+<i>GLCM</i>+<i>Tamura</i>, <img src="https://www.techscience.com/ueditor/files/jrm2.png" height="20px">+<i>GLCM</i>+<i>Tamura</i> and <img src="https://www.techscience.com/ueditor/files/jrm3.png" height="20px"> +<i>GLCM</i>+<i>Tamura</i> were obtained. The five fused features were classified by extreme learning machine and BP neural network. The classification effect of feature <img src="https://www.techscience.com/ueditor/files/jrm1.png" height="20px">+<i>GLCM</i>+<i>Tamura</i> combined with extreme learning machine was the best, and the classification accuracy of cross, radial and tangential sections reached 100%, 97.63% and 94.72%, respectively, which is 0.83%, 2.77% and 5.70% higher than that of BP neural network. The classification running time of ELM is less than 1 s, and the classification efficiency is high. In conclusion, the <img src="https://www.techscience.com/ueditor/files/jrm1.png" height="20px">+<i>GLCM</i>+<i>Tamura</i> method combined with extreme learning machine can be used as a quick and accurate classifier, providing an efficient and feasible classification method of rosewood.

Features of the formation of a collection of models of the screw ships of the second half of the 19th century on the basis of the recreated Maritime Museum with the participation of Grand Duke Admiral General Konstantin Nikolaevich Romanov

In this article, the author considers the issue related to the restoration of the collection of ship models of the Maritime Museum. He understood that within the framework of this article it is impossible to display all the processes of recreating the collection of models of ships of the second half of the 19th century, and did not set himself the task of describing the work of fleet managers and ship modelers. He set himself a more modest task: to describe the features of the formation of the collection. The author emphasizes that the models included in the collection were made at that time in the Model Chamber in St Petersburg and the Model Workshop of the St Petersburg port. Indicates that both precious wood species and simple and metal were used in their manufacture. The author emphasizes that the Grand Duke Admiral General Konstantin Nikolayevich took an active part in promoting museum exhibitions to the world level. Analyzing the content of the documents, the author concludes that the lost collection of models had to be replenished, and thus restore the missing event series in the history of the Russian Navy. And also that during the reconstruction of the Maritime Museum, objects which were received from different places, were attributed. The article also explains the peculiarities of the formation of the collection of the newly recreated Maritime Museum and the fact that the models made by the masters of the second half of the 19th century are unique today. The author recalls that the reopening of the newly recreated Maritime Museum took place on August 27, 1867, and Lieutenant Nikolai Mikhailovich Baranov was appointed its director on December 31, 1866.

Anti-Melanogenic Activity of Calocedrus formosana Wood Essential Oil and Its Chemical Composition Analysis.

Calocedrus formosana (Cupressaceae) is one of the five precious woods of Taiwan. In this study, we investigated the anti-melanogenic activity of C. formosana wood essential oil (CFEO) and its bioactive components in vitro. Initially, CFEO exhibited strong mushroom tyrosinase activity in the cell-free mushroom tyrosinase assay system with an IC50 value of 2.72 µg/mL. Next, treatment with CFEO significantly as well as dose-dependently reduced a combination of α-melanocyte-stimulating hormone and forskolin (α-MSH-FSK)-induced melanin synthesis in B16-F10 cells. Indeed, 80 μg/mL CFEO completely inhibited melanin production, which is similar to that of control cells. Further studies revealed that treatment with CFEO significantly inhibited melanogenesis regulatory proteins, including TRP-1, TRP-2, and MITF, whereas tyrosinase was unaffected by either α-MSH-FSK or CFEO. In addition, the composition of the CFEO was characterized. The major components of CFEO were α-terpineol (23.47%), shonanic acid (10.45%), terpinen-4-ol (12.23%), thymol (5.3%), piperitone (3.44%), berbenone (2.81%), thujic acid (1.65%), and chaminic acid (0.13%). Among them, shonanic acid (1), thujic acid (2), and chaminic acid (3) were uncommon constitutes in essential oils, which could be the index compounds of CFEO, and the structure of these compounds were confirmed by spectral analysis. Furthermore, we found that thymol is an active ingredient responsible for CFEO’s anti-melanogenic activity. Based on these results, we suggest that CFEO or thymol could be a potential candidate for the development of skin whitening products for cosmetic purposes.

Comparative wood anatomy of 15 Malagasy Diospyros species (Ebenaceae)

Summary Diospyros L. (Ebenaceae) is an important source of ebony, a precious wood used for several economically important timber products. Species are overexploited in many regions, including Madagascar, for both the national and international trade, but little is known about their wood anatomy, despite its importance for forensic identification. Wood anatomy has a major role to play in ensuring the sustainable and equitable utilization of Diospyros species that are not threatened by extinction, and in law enforcement to protect threatened species from illegal logging. This study aims to identify, describe, and test the usefulness of anatomical features to support a taxonomic revision of the genus in Madagascar and to enrich databases for wood identification. Ninety-nine wood specimens were collected from the various bio-geographical regions of Madagascar, representing 15 endemic species (twelve previously described and three new) of large trees (reaching DBH ⩾ 20 cm and/or height ⩾ 20 m) were investigated. Standard methods for wood anatomical studies were used. Statistical analysis of the data using Factorial Analysis on Mixed Data was performed for 14 wood anatomical characters. Detailed descriptions and comparisons of the wood anatomy of the 15 species are provided, along with a wood identification key. Analyses showed that all the characters are highly significant () in the separation of the species studies.

Measuring the tensile strain of wood by visible and near-infrared spatially resolved spectroscopy

Strain measurement is critical for wood quality evaluation. Using conventional strain gauges constantly is high cost, also challenging to measure precious wood materials due to the use of strong adhesive. This study demonstrates the correlation between the light scattering degrees inside the wood during tension testing and their macroscopic strain values. A multifiber-based visible-near-infrared (Vis–NIR) spatially resolved spectroscopy (SRS) system was designed to rapidly and conveniently acquire such light scattering changes. For the preliminary experiment, samples with different thicknesses, from 2 to 5 mm, were measured to evaluate the influence of sample thickness. The differences in Vis–NIR SRS spectral data diminished with an increase in sample thickness, suggesting that the SRS method can successfully measure the wood samples' whole strain (i.e., surface and inside). Then, for the primary experiment, 18 wood samples were each prepared with approximately the same sample thickness of 2 mm and 5 mm to construct strain calibration models, respectively. The prediction accuracy of the 2-mm samples was characterized by a determination coefficient (R2) of 0.81 with a root mean squared error (RMSE) of 343.54 με for leave-one-out cross-validation; for test validation, the validation accuracy was characterized by an R2 of 0.76 and an RMSE of 395.35 με. For the validation accuracy of the 5-mm samples, R2val was 0.69 with 440.78 με RMSEval. Overall, the presented calibration results of the SRS approach were confirmed to be superior to the standard diffuse reflectance spectroscopy.

Genome-wide detection and classification of terpene synthase genes in Aquilaria agallochum.

The online version contains supplementary material available at 10.1007/s12298-021-01040-z.

The Shikar and Hunting: Eradication of Wildlife in Colonial Jungle Mahal

Abstract The article depicts a broader discourse on 'Hunting' or Shikar in the areas designated as 'Jungle Mahal' and the critical impacts of related activities on the socio-economic conditions of the local inhabitants living in and around the forests. During the early nineteenth century, this region was covered with thick forests and was home to various species of wild animals. The tribal population living in and around this jungle terrain had been thriving, from time immemorial, on shifting cultivation, cattle grazing and hunting. Their lives revolved around the attributes and ethos of the forests around them. The article focuses on Shikar or hunting practices of the tribal people as well as the organised hunting expeditions conducted by the then British administrators, European hunters and native kings over a period of more than one hundred years, starting from the early nineteenth century. Hunting expeditions and the commercial trading of precious wood set in motion the process of random destruction of wild animals and the forests of Jungle Mahal.

Wood microscopic image identification method based on convolution neural network

To prevent the illegal trade of precious wood in circulation, a wood species identification method based on convolutional neural network (CNN), namely PWoodIDNet (Precise Wood Specifications Identification) model, is proposed. In this paper, the PWoodIDNet model for the identification of rare tree species is constructed to reduce network parameters by decomposing convolutional kernel, prevent overfitting, enrich the diversity of features, and improve the performance of the model. The results showed that the PWoodIDNet model can effectively improve the generalization ability, the characterization ability of detail features, and the recognition accuracy, and effectively improve the classification of wood identification. PWoodIDNet was used to analyze the identification accuracy of microscopic images of 16 kinds of wood, and the identification accuracy reached 99%, which was higher than the identification accuracy of several existing classical convolutional neural network models. In addition, the PWoodIDNet model was analyzed to verify the feasibility and effectiveness of the PWoodIDNet model as a wood identification method, which can provide a new direction and technical solution for the field of wood identification.