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Overview of current practices in data analysis for wood identification. A guide for the different timber tracking methods.

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Today we have five types of timber tracking tools available. Each has its own strengths and limitations (see the Timber Tracking Tool Infogram), but together they offer a broad range of methods that can assist us in identifying the botanical as well as the geographic origin (provenance) of most kinds of timber samples, even those smaller than 1 cm³. With this guide we want to provide an overview of the current best-practice methods used to analyse data derived from different wood identification methods, while presenting their respective strengths and limitations. We give advice on data analysis, from the development of reference data, through to the verification of identity and provenance of unknown samples against the reference database. We end with an expert view on combining methods for wood identification and discuss how timber identification possibilities could expand in the future.
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... To ensure Table 1. Protocol for the construction of a xylarium (Bridson and Forman 2010;British Columbia Ministry of Forests 1996;Esteban et al. 2012;Perkins 2022;RHS -Royal Horticultural Society 2013;Schmitz et al. 2019Schmitz et al. , 2020Wiedenhoeft 2014). ...
... Especially for xylarium, the drying time depends, among other factors, on the thickness of the sample, the species density, the season of collection and the drying conditions. For a Table 4. Protocol for xylarium and herbarium field description and specimen labelling (Bridson and Forman 2010;British Columbia Ministry of Forests 1996;Perkins 2022;RHS -Royal Horticultural Society 2013;Schmitz et al. 2019Schmitz et al. , 2020. ...
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The significance of plant material sample deposits extends beyond the scientific community, with various industries, historians, and law enforcement agencies increasingly relying on them. Preserving global xylariums and herbariums is essential for accessing centuries of data, species, and samples that may no longer exist in their original locations or may be extinct. While maintaining these archives is crucial, it is equally important to ensure proper collection, structure, organization, and classification of new xylariums and herbariums. In that order, a preventive conservation approach is essential to ensure future research by defining actions, materials, and uses to prevent degradative factors and potential harm to the collection This guarantees future accessibility to valuable samples and the knowledge they offer. The paper explores key factors in xylarium and herbarium construction and preservation, including sample drying, pest control, preventive measures, archival materials, facilities, and handling procedures. ARTICLE HISTORY
... To date, the lack of accessible reference samples of relevant species and analytical methodologies designed for the verification of manufacturer-supplied data has been constantly shrinking. Forensic identification techniques for wood, can broadly be categorized as anatomical, chemical, and genetic methodologies Low et al. 2022;Lowe and Cross 2011;Schmitz et al. 2020). Solid wood is generally easier to identify using different methods with similarly good results (Ravindran and Wiedenhoeft 2020). ...
... Wood-based products such as pulp, paper and particle board tend to be more difficult to identify than solid wood (Sieburg-Rockel and Koch 2020). The selection of the most appropriate technique depends on the specific identification inquiry in question Schmitz et al. 2019Schmitz et al. , 2020. Notably, for the genus-level identification of pulp and paper products, exclusively anatomical and chemotaxonomic approaches prove applicable. ...
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This paper presents a comparative analysis of the blind test outcomes of two independent methods for the identification of tropical wood species in pulp and paper products. Both, the established anatomical and the relatively new chemotaxonomic method support the European Deforestation Regulation 2023/1115 (EUDR), which aims to ensure that only legally harvested timber that has not contributed to deforestation is traded in the EU. The blind test involved 570 decisions on 15 test sheets of 37 self-manufactured mixed tropical hardwood pulps and an industrial beech pulp, used as a matrix. Both detection techniques demonstrated robust performance with over 80 % hit rates. The results show that the synergies and combination of the strengths of both methods can be utilized and lead to even better combined performance. In order to establish the chemotaxonomic identification method as a complement to the conventional anatomy-based method, statistical analyses were performed to assess its intermediate precision between three different GC-MS systems. In most cases, the method gave consistent results independent of the instrument used.
... Qualitative features are generally well preserved after the charring process. Alvin 1983, 1986;Rossen and Olson 1985;Prior and Gasson 1993;Ger-isch 2004;Kim and Hanna 2006;Kwon et al. 2009;Dias Leme et al. 2010;Nelle and Bankus 2012;Hubau et al. 2013;Goncalves et al. 2014;Goncalves and Scheel-Ybert 2016;Haag et al. 2020;Haag et al. 2023;Schmitz et al. 2020;Zemke et al. 2020). Only long-lasting charring temperatures of well over 800 °C (Dias Leme et al. 2010) can lead to fusion in the tissue and make it difficult to determine anatomical features. ...
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Species identification of carbonized wood holds significance for various scientific disciplines, including botany, palaeontology, and archaeology. Identification also contributes to the preservation of endangered wood species and forests, and supports climate research. With regard to the identification of wood and wood products, all international research institutions adhere to the IAWA list of microscopic features for hardwood and softwood identification, established by the IAWA Committee in 1989. Our comparative anatomical studies of 30 different species reveal significant dimensional losses of quantitative features during the charring process. Specifically, the findings indicate a shift in size classes, with varying percentages of loss in anatomical features from solid wood to charcoal for most of the taxa analyzed. Consequently, the size classes defined in databases for solid wood differentiation cannot be directly applied to charcoal identification. Furthermore, the present study employs statistical evaluations to illustrate the application of conventional size classes for the parameters: tangential diameter of vessel elements, intervessel pit diameter, ray height, and width. The implications of these findings for charcoal research are discussed in detail.
... The pervasive problem of fraud and misrepresentation in wood products trade, including the trafficking of illegally harvested materials, has encouraged the development of technology-driven wood identification methods utilizing advancements in computer vision and machine learning; DNA extraction and analysis; chemical-spectral analysis; and other areas to increase wood identification capacity and reduce reliance on human-based conventional wood identification techniques (Johnson and Laestadius 2011;Dormontt et al. 2015;Koch et al. 2015;Lowe et al. 2016;UNODC 2016;Beeckman et al. 2020). Computer-vision wood identification (CVWID) systems such as the XyloTron, XyloPhone, AIKO, MyWood-ID, and others have shown promise as rapid, low-cost, fielddeployable tools for democratizing wood identification capacity among the front-line defenders of fair-trade including customs officials and procurement personnel (Hermanson and Wiedenhoeft 2011;Tang et al. 2018;Ravindran et al. 2018Ravindran et al. , 2020Ravindran et al. , 2022aDamayanti et al. 2019;Wiedenhoeft 2020). ...
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Hardwood porosity domains (diffuse-, semi-ring-, and ring-porosity) exist along a spectrum with some taxa embodying only one porosity domain and others spanning more than one. A cascading model scheme involving a root-level porosity classifier and second-level taxonomical classifiers might be useful for mitigating reductions in the predictive accuracy of North American computer vision wood identification (CVWID) models when the number of classes increases. Thus far, the porosity classifier has been trained on images covering the breadth of the porosity spectrum. By reducing ambiguity near the boundaries of porosity domains, training the root classifier only on taxa that are quintessentially diffuse-, semi-ring, and ring-porous might produce equivalent or better results. In this study, a two-class (diffuse-and ring-porous) model and a three-class (diffuse-, semi-ring-, and ring-porous) model were trained on specimens only from taxa with quintessentially idealized porosity and tested on specimens with and without idealized porosity. Results showed perfect predictive accuracy for both models when tested on in-model taxa but showed lower accuracy on datasets with non-ideal porosity with all misclassifications being anatomically sensible. In addition, the results showed remarkable similarities between CVWID models and humans in how they "apply" the concept of discrete porosity domains to a real-world continuum.
... The mass spectra, for example, from endangered wood species or various petroleum oil types, have been collated and used to determine an unknown sample's "chemical fingerprint." Heatmaps created from sample spectra show the relative abundance of ions in a mass spectrum, allowing analysts to visually compare sample chemotypes and m/z ion intensity to reference materials (Tikkisetty et al., 2023a, b;Schmitz et al., 2020). Additional related software allows heatmaps to work in tandem with multivariate statistical methods, such as the principal component analysis (PCA) and the discriminant analysis of principal component (DAPC) to visually examine clusters of chemotypically similar data. ...
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Spilled plant-based oils behave very differently in comparison to petroleum oils and require different clean-up measures. They do not evaporate, disperse, dissolve, or emulsify to a significant degree but can polymerize and form an impermeable cap on sediment, smothering benthic media and resulting in an immediate impact on the wildlife community. The current study explored the application of rapid up-to-date direct analysis in real time (DART) with high-resolution mass spectrometry for plant-based oil typing. The study introduced a new concept of using hydrophobic paper to collect and analyze oil samples, thus minimizing sample preparation and expenses. Application of this technique showed its ability to speedily distinguish plant-based from petroleum-based oils. A microcosm experiment exposing plant-based oil samples to weathering processes for comparison with petroleum-based oils demonstrated the ability of the method to classify weathered oil samples and identify their source oil. It was observed that canola and peanut oil were the most resistant to weathering processes. The developed DART-TOFMS method was shown to be accurate for short-term weathered oil spills up to between 12 and 26 days of exposure. The developed method performed identification in less than a day compared to the established multi-day method for oil spill forensics requiring careful sample collection in glass containers, time-consuming laboratory clean-up, lengthy gas chromatography sequences, and careful integration including integration of retention time markers.
... Therefore, neither genetics, stable isotopes nor NIR spectroscopy can be used. It is therefore not possible to analyze the origin [2,3]. Recently a new, very complex chemotaxonomic method for determining wood species was introduced for the first time [4]. ...
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Wood species identification plays a crucial role in various industries, from ensuring the legality of timber products to advancing ecological conservation efforts. This paper introduces WoodYOLO, a novel object detection algorithm specifically designed for microscopic wood fiber analysis. Our approach adapts the YOLO architecture to address the challenges posed by large, high-resolution microscopy images and the need for high recall in localization of the cell type of interest (vessel elements). Our results show that WoodYOLO significantly outperforms state-of-the-art models, achieving performance gains of 12.9% and 6.5% in F2 score over YOLOv10 and YOLOv7, respectively. This improvement in automated wood cell type localization capabilities contributes to enhancing regulatory compliance, supporting sustainable forestry practices, and promoting biodiversity conservation efforts globally.
... This study is part of an extensive project that aims the traceability and authenticity of Amazonian wood based on its elemental profile. Such approach can allow the accurate identification of wood samples, once provided a robust and comprehensive database (Schmitz et al., 2020). Here, neutron activation analysis (NAA), a primary method of measurement (Greenberg et al., 2011), was used to evaluate the elemental profile and its radial distribution in three different Ipê species with high occurrence in the Amazon Rainforest: Handroanthus serratifolius (yellow Ipê), Handroanthus impetiginosus (purple Ipê), and Handroanthus leucophloeus (yellow Ipê). ...
... Addressing these challenges, dendro-provenancing has emerged as a critical tool, enhancing our knowledge of past wood harvesting and mobility, and aiding in the tracking of illegal timber logging and exports. To identify geographic provenance and wood species, various methods with unique strengths, such as varying resolution levels, and limitations, including high costs and time consumption, are often combined to enhance accuracy and comprehensiveness (Beeckman et al., 2020). Dendrochronology, the primary method in historical wood provenance studies, often overlooks multiple variables affecting tree-ring patterns (Visser, 2021). ...
... ForeST© as described typically uses Mass Mountaineer software as a shell to develop and access standard reference data-styled libraries housed within the National Institute of Standards and Technology (NIST) MS Search Program [24]. Notably, the Forest© libraries are developed by FWS and partners in-house from the reference wood samples and are not controlled or curated by NIST. ...
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The mass spectral database of tree species built by US Fish and Wildlife Service has thousands of entries and has been a valuable resource to combat illegal logging and international trade. The database was and continues to be constructed using a particular ambient ionization time-of-flight mass spectrometry (TOF-MS) platform in the agency branch in Ashland, OR, with which queries of unknown wood samples are investigated exclusively. Laboratories that operate different MS instruments also have an interest in using the database if they can produce valid matches to known samples compatible with the database. Four species were selected for inter-laboratory comparison using Orbitrap MS instruments and the equivalent TOF-MS platform with direct analysis in real time ionization of institution-sourced wood samples. Identities of the known samples were confirmed by examination of their microscopic wood anatomy. Orbitrap analysis was able to identify each species as confidently as the TOF instruments, often with less variation in spectra but not necessarily greater mass accuracy or better-matched signal abundance to the control database. The Orbitrap program also had to be doubled to two scanned mass ranges appended for greater peak intensity, before spectra could be correctly matched to the database, but the program was successful.
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The highly valuable timber species Dalbergia cochinchinensis is severely threatened due to habitat loss and illegal logging throughout its distribution in mainland Southeast Asia and is listed on CITES Appendix II. This study proposes a strategy for conservation and sustainable management of the species based on assessment of genetic structure within and among natural populations. We developed SNP markers from RAD sequencing and used these in combination with SSR genotypes from a previous study to assess the genetic diversity in 26 populations of D. cochinchinensis across its entire range in Laos, Thailand, Cambodia and Vietnam. The species is able of clonal reproduction and we found that trees closer than 45 meters from each other can be clones. Genetic diversity and clustering analysis showed a clear division of populations into five geographical groups with differing levels of diversity. Assignment tests correctly identified the region of origin for approximately 90% of the samples, which demonstrates that despite a low number of successfully identified SNPs, the SSR + SNP marker panel has the potential for tracking the geographic origin of D. cochinchinensis timber for use in CITES regulation and enforcement. We propose the five identified groups to be considered as Management Units and that conservation and breeding programs should be based on a network of in situ and ex situ conservation stands representing the genetic variation among and within these units. We recommend that conservation efforts are directed towards community owned and managed lands, as this has proven an effective strategy locally.
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