Alex Charles Wiedenhoeft

Forest Products Laboratory, Madison, WI, USA · Center for Wood Anatomy Research

Prior work on computer-vision wood identification (CVWID) for North American hardwoods yielded two independent deep learning models – a 22-class model for diffuse-porous woods and a 17-class model for ring-porous woods – but did not address semi-ring-porous woods nor provide a CVWID solution for an unknown specimen without a human first determining...

Distribution shift, a phenomenon in machine learning characterized by a change in input data distribution between training and testing, can reduce the predictive accuracy of deep learning models. As operator and hardware conditions at the time of training are not always consistent with those after deployment, computer vision wood identification (CV...

Previous studies on computer vision wood identification (CVWID) have assumed or implied that the quality of sanding or knifing preparation of the transverse surface of wood specimens could influence model performance, but its impact is unknown and largely unexplored. This study investigates how variations in surface preparation quality of test spec...

Preveli i priredili: Milan Gavrilović i Pedja Janaćković

The career of Sherwin J. Carlquist was marked by numerous pioneering contributions to botany and especially to ecological and evolutionary wood anatomy. He developed some of the most important modern functional hypotheses for wood, including postulating a biomechanical and fluid dynamic role for helical thickenings (HT) in seasonally dry environmen...

Due to increasing global trade of timber commodities and illegal logging activities, wood species listed in the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) appendices are facing extinction, and their international trade has been banned or is under supervision. Reliable and applicable species-level discrim...

Dimensional movement with changing moisture content is among the main performance characteristics of wood flooring. The U.S. wood flooring industry has relied on values and equations published by the Forest Products Laboratory (FPL) in its Wood Handbook to provide critical information about how different woods move. This paper discusses key informa...

Wood identification is vitally important for ensuring the legality of North American hardwood value chains. Computer vision wood identification (CVWID) systems can identify wood without necessitating costly and time-consuming off-site visual inspections by highly trained wood anatomists. Previous work by Ravindran and colleagues presented macroscop...

Background Illegal logging is a global crisis with significant environmental, economic, and social consequences. Efforts to combat it call for forensic methods to determine species identity, provenance, and individual identification of wood specimens throughout the forest products supply chain. DNA-based methodologies are the only tools with the po...

Computer vision wood identification (CVWID) has focused on laboratory studies reporting consistently high model accuracies with greatly varying input data quality, data hygiene, and wood identification expertise. Employing examples from published literature, we demonstrate that the highly optimistic model performance in prior works may be attribute...

Availability of and access to wood identification expertise or technology is a critical component for the design and implementation of practical, enforceable strategies for effective promotion, monitoring and incentivisation of sustainable practices and conservation efforts in the forest products value chain. To address this need in the context of...

Illegal logging is a major threat to forests in Peru, in the Amazon more broadly, and in the tropics globally. In Peru alone, more than two thirds of logging concessions showed unauthorized tree harvesting in natural protected areas and indigenous territories, and in 2016 more than half of exported lumber was of illegal origin. To help combat illeg...

Field deployable computer vision wood identification systems can play a key role in combating illegal logging in the real world. This work used 764 xylarium specimens from 84 taxa to develop an image data set to train a classifier to identify 14 commercial Colombian timbers. We imaged specimens from various xylaria outside Colombia, trained and eva...

You can purchase copies of this book by contacting Prof. Baas or Prof Yin. IAWA members can access content on line at https://brill.com/view/journals/iawa/41/4/iawa.41.issue-4.xml Pieter Baas <pieter.baas@naturalis.nl> Yafang Yin <yafang@caf.ac.cn> There may be long delays in receiving copy by mail due to the COVID

One rate-limiting factor in the fight against illegal logging is the lack of powerful, affordable, scalable wood identification tools for field screening. Computer vision wood identification using smartphones fitted with customized imaging peripherals offers a potential solution, but to date, such peripherals suffer from one or more weaknesses: low...

A wealth of forensic wood identification technologies has been developed or improved in recent years, with many attempts to compare results between technologies. The utility of such comparisons is greatly reduced when the species tested with each technology are different and when performance metrics are not calculated or presented in the same way....

One rate-limiting factor in the fight against illegal logging is the lack of powerful, affordable, scalable wood identification tools for field screening. Computer vision wood identification using smartphones fitted with customized imaging peripherals offer a potential solution but to date, such peripherals suffer from one or more weaknesses: low i...

Forests, estimated to contain two thirds of the world’s biodiversity, face existential threats due to illegal logging and land conversion. Efforts to combat illegal logging and to support sustainable value chains are hampered by a critical lack of affordable and scalable technologies for field-level inspection of wood and wood products. To meet thi...

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...

Illegal logging and associated trade aggravate the over-exploitation of Swietenia species, of which S. macrophylla King, S. mahagoni (L.) Jacq, and S. humilis Zucc. have been listed in Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) Appendix Ⅱ. Implementation of CITES necessitates the development of efficient...

Computer vision systems for wood identification have the potential to empower both producer and consumer countries to combat illegal logging if they can be deployed effectively in the field. In this work, carried out as part of an active international partnership with the support of UNIDO, we constructed and curated a field-relevant image data set...

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, surv...

Timber genus identification based on the anatomical features of wood is well established in botany. However, species-level wood identification is not always possible based on traditional wood morphology techniques alone. To compensate for the deficiencies of traditional methods, direct analysis in real time coupled to Fourier transform ion cyclotro...

Main conclusion Machine-learning approaches (MLAs) for DNA barcoding outperform distance- and tree-based methods on identification accuracy and cost-effectiveness to arrive at species-level identification of wood. DNA barcoding is a promising tool to combat illegal logging and associated trade, and the development of reliable and efficient analytic...

The short guide gives an overview of the current capacities of the different timber tracking tools. The only way to be sure that a wood (product) at the end of the supply chain is what the documents say it is, is to check the inherent wood characteristics that can reveal species and geographic identity. There is an increasing interest to bring cla...

Near-infrared spectroscopy (NIRS) is a potential, field-portable wood identification tool. NIRS has been studied as tool to identify some woods but has not been tested for Dalbergia. This study explored the efficacy of hand-held NIRS technology to discriminate, using multivariate analysis, the spectra of some high-value Dalbergia wood species: D. d...

This paper focuses on the material study (radiocarbon dating, wood identification and strontium isotope analyses) of four large ‘India occidentali’ clubs, part of the founding collections of the Ashmolean Museum, in Oxford, and originally part of John Tradescant’s ‘Ark’, in Lambeth (1656). During the seventeenth century, the term ‘India occidentali...

Background The current state-of-the-art for field wood identification to combat illegal logging relies on experienced practitioners using hand lenses, specialized identification keys, atlases of woods, and field manuals. Accumulation of this expertise is time-consuming and access to training is relatively rare compared to the international demand f...

Main conclusion: ITS2+ trnH - psbA was the best combination of DNA barcode to resolve the Dalbergia wood species studied. We demonstrate the feasibility of building a DNA barcode reference database using xylarium wood specimens. The increase in illegal logging and timber trade of CITES-listed tropical species necessitates the development of unambi...

We report on the results of a multi-disciplinary project (including wood identification, radiocarbon dating and strontium isotope analysis) focused on a collection of pre-Columbian wooden carvings and human remains from Pitch Lake, Trinidad. While the lake's unusual conditions are conducive to the survival of organic artefacts, they also present pa...

The Pigorini cemí is an icon of Caribbean colonial history, reflecting early trans-Atlantic cross-cultural exchanges. Although well documented, the piece has received surprisingly little systematic study. We present the first structural analysis and radiocarbon dating of the sculpture (modelled at AD 1492-1524), and a brief discussion of the materi...

Since the mid-19th century, rare prehistoric wooden carvings and human skeletal remains have been dredged from Pitch Lake, Trinidad, during commercial asphalt mining. Establishing a chronology for these objects is challenging, due to both a lack of stratigraphic and contextual information and the necessity to completely remove any pitch to ensure a...

Background and aims: Wood is a major innovation of land plants, and is usually a central component of the body plan for two major plant habits: shrubs and trees. Wood anatomical syndromes vary between shrubs and trees, but no prior work has explicitly evaluated the contingent evolution of wood anatomical diversity in the context of these plant hab...

In May 2014, the Member States of the United Nations adopted Resolution 23/1 on “strengthening a targeted crime prevention and criminal justice response to combat illicit trafficking in forest products, including timber.” The resolution promotes the development of tools and technologies that can be used to combat the illicit trafficking of timber....

Big-leaf mahogany is the world's most valuable widely traded tropical timber species and Near Infrared Spectroscopy (NIRS) has been applied as a tool for discriminating its wood from similar species using multivariate analysis. In this study four look-alike timbers of Swietenia macrophylla (mahogany or big-leaf mahogany), Carapa guianensis (crabwoo...

Nearly 400 million years of evolution and field-testing by the natural world has given humans thousands of wood types, each with unique structure–property relationships to study, exploit, and ideally, to manipulate, but the slow growth of trees makes them a recalcitrant experimental system. Variations in wood features of two genotypes of peach (Pru...

Seasonal cambial activity was investigated in one- to three-year-old branch modules (branch constructional units) of ten woody species from cerrado sensu stricto, a savanna-like ecosystem, of southern Brazil. Relationships between cambial activity and environmental factors (precipitation, temperature, day length) and leaf production were tested usi...

Forest-derived biomaterials can play an integral role in a sustainable and renewable future. Research across a range of disciplines is required to develop the knowledge necessary to overcome the challenges of incorporating more renewable forest resources in materials, chemicals, and fuels. We focus on wood specifically because in our view, better c...

L’identificazione dei legni costituisce il primo pas- so per ottenere conoscenze indispensabili in molti ambiti di studio. Ad esempio, prima di eseguire il restauro di un manufatto di interesse culturale è indispensabile conoscere il nome dei legni che lo compongono. Oppure, nel caso in cui si sospetti che un legno protetto da convenzioni internazi...

Recent work has highlighted the importance of movement of chemicals and ions through the wood cell wall. This movement depends strongly on MC and is necessary for structural damage mechanisms such as fastener corrosion and wood decay. Here, we present the first measurements of electrical resistance of southern pine at the subcellular level as a fun...

The elastic properties of pit membranes are reported to have important implications in understanding air-seeding phenomena in gymnosperms, and pit aspiration plays a large role in wood technological applications such as wood drying and preservative treatment. Here we present force-displacement measurements for pit membranes of circular bordered pit...

Glacial deposition and fluvial/lacustrine sedimentation interact over terrains in central New York State to preserve a history of geological and hydrological events as well as hydroclimatic transitions. The lower reach of Fish Creek draining the eastern watershed of Oneida Lake, NY, is an area with prominent wood remains. This study explores a coll...

With the adoption of a number of anti-illegal logging laws, treaties, memoranda, and international agreements around the world, there is broad and renewed interest in wood identification, especially in the field at the macroscopic level. In response to this interest, and to begin to fill an obvious gap in the corpus of wood anatomical reference mat...

Electrical impedance spectra of wood taken at macroscopic scales below the fibre saturation point have led to inferences that the mechanism of charge conduction involves a percolation phenomenon. The pathways responsible for charge conduction would necessarily be influenced by wood structure at a variety of sub-macroscopic scales – at a mesoscale –...

Root and stem wood anatomy of C. myrianthum (Verbenaceae) from a semideciduous seasonal forest in Botucatu municipality (22°52′20″S and 48°26′37″W), São Paulo state, Brazil, were studied. Growth increments demarcated by semi-ring porosity and marginal bands of axial parenchyma were observed in the wood of both root and stem. Many qualitative featur...

Figure can add value to wood products, but its occurrence is unpredictable. A first step in reliably producing figured wood is determining whether it is faithfully transmitted to progeny via sexual and asexual reproduction. We describe a 26-year-old male aspen genotype, designated ‘Curly Poplar’, which was shown to be a Populus × canescens hybrid u...

Wood has played a major role throughout human history. Strong and versatile, the earliest humans used wood to make shelters, cook food, construct tools, build boats, and make weapons. Recently, scientists, politicians, and economists have renewed their interest in wood because of its unique properties, aesthetics, availability, abundance, and perha...

This paper establishes a chronological framework for selected pieces of Caribbean (TaÃno/Lucayan) wooden sculpture, enabling previously ahistoric artefacts to fit back into the wider corpus of pre-colonial material culture. Seventy-two 14C AMS determinations from 56 artefacts held in museum collections are reported, including 32 ceremonial duhos, o...

This paper examines phase transformations of water in wood and isolated wood cell wall components using differential scanning calorimetry with the purpose of better understanding “Type II water” or “freezable bound water” that has been reported for cellulose and other hydrophilic polymers. Solid loblolly pine (Pinus taeda) milled pine, and holocell...

Radiocarbon dating of historical and archaeological wood can be complicated, sometimes involving issues of "inbuilt" age in slow-growing woods, and/or the possibility of reuse or long delays between felling and use of the wood. Terminus dates can be provided by dating the sapwood, or the outermost edge of heartwood, while a date from the pith can g...

Five wooden sculptures from the pre-contact Caribbean, long held in museum collections, are here dated and given a context for the first time. The examples studied were made from dense Guaiacum wood, carved, polished and inlaid with shell fastened with resin. Dating the heartwood, sapwood and resins takes key examples of ‘Classic’ Taíno art back to...

The results of AMS dating and wood identification on three carvings recovered from the southern Lesser Antilles (Dominica, Battowia and Trinidad) are discussed, placing the objects in the context of events and interactions that spanned the region's prehistory from the fifth to fifteenth centuries AD. Each hints at a rich legacy - of their passage t...

The need for accurate and rapid field identification of wood to combat illegal logging around the world is outpacing the ability to train personnel to perform this task. Despite increased interest in non-anatomical (DNA, spectroscopic, chemical) methods for wood identification, anatomical characteristics are the least labile data that can be extrac...

To better understand the performance of bonded, coated, and modified wood, knowledge of how these processes alter the dimensional change and mechanical properties of wood at a given moisture content (MC) are important. These localized influences on earlywood (EW) and latewood (LW) properties are not well understood. In the present study, the influe...

Firewood is a major pathway for the inadvertent movement of bark- and wood-infesting insects. After discovery of Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) in southeastern Michigan in 2002, quarantines were enacted including prohibition of transporting firewood across the Mackinac Bridge between Michigan's Lower and Upper peninsulas. D...

Most of the arborescent Croton species in the New World were treated by Webster as belonging either to C. sect. Cyclostigma Griseb. or C. sect. Luntia (Neck. ex Raf.) G.L. Webster. The circumscription of C. sect. Cyclostigma has been treated recently. In this paper we focus on C. sect. Luntia, which was subdivided by Webster into two subsections, C...

Most of the arborescent Croton species in the New World were treated by Webster as belonging either to C. sect. Cyclostigma Griseb. or C. sect. Luntia (Neck. ex Raf.) G.L. Webster. The circumscription of C. sect. Cyclostigma has been treated recently. In this paper we focus on C. sect. Luntia, which was subdivided by Webster into two subsections, C...

Water-soluble extractives (WSE) and solventsoluble extractives (SSE) can cause premature finish failure on wood. Both classes of extractives have predictable properties based on their chemistry and location within the wood. Prevent WSE bleed by using dry wood; eliminate the intrusion of water with good design and building practices. Both WSE and SS...

Color, odor, and natural durability of heartwood are characteristics imparted by a class of chemicals in wood known as extractives. Water-soluble extractives (WSE) and solvent-soluble extractives (SSE) can cause premature finish failure on wood. Finish formulations have been developed that are effective at blocking stains resulting from WSE from co...