Alex C. Wiedenhoeft

A brief review of machine vision in the context of automated wood identification systems

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 extracted from solidwood products, independent of wood processing (sawing, drying, microbial attack). Wood identification using anatomical characteristics is thus still a viable approach to the wood identification problem, and automating the process of identification is an attractive and plausible solution. The undisputed increase of computer power and image acquisition capabilities, along with the decrease of associated costs, suggests that it is time to move toward non-human based automated wood identification systems and methods. This article briefly reviews the foundations of image acquisition and processing in machine vision systems and overviews how machine vision can be applied to wood identification.

CLIMATE IN THE GREAT LAKES REGION BETWEEN 14,000 AND 4000 YEARS AGO FROM ISOTOPIC COMPOSITION OF CONIFER WOOD

The isotopic composition of ancient wood has the potential to provide information about past environments. We analyzed the δ13C, δ18O, and δ2H of cellulose of conifer trees from several cross-sections at each of 9 sites around the Great Lakes region ranging from ~4000 to 14,000 cal BP. Isotopic values of Picea, Pinus, and Thuja species seem inter- changeable for δ18O and δ2H comparisons, but Thuja appears distinctly different from the other 2 in its δ13C composition. Iso- topic results suggest that the 2 sites of near-Younger Dryas age experienced the coldest conditions, although the Gribben Basin site near the Laurentide ice sheet was relatively dry, whereas the Liverpool site 500 km south was moister. The spatial isotopic variability of 3 of the 4 sites of Two Creeks age shows evidence of an elevation effect, perhaps related to sites farther inland from the Lake Michigan shoreline experiencing warmer daytime growing season temperatures. Thus, despite floristic similarity across sites (wood samples at 7 of the sites being Picea), the isotopes appear to reflect environmental differences that might not be readily evident from a purely floristic interpretation of macrofossil or pollen identification.

Brasiliocroton, a New Crotonoid Genus of Euphorbiaceae s.s. from Eastern Brazil

Abstract A new genus and species of Euphorbiaceae s.s., Brasiliocroton mamoninha, is described from two disjunct areas of lowland forest remnants in eastern and northeastern Brazil. It is a member of tribe Crotoneae and was previously confused with Croton and Micrandra. The resemblance to Micrandra is based on the branched inflorescences and terminal position of the pistillate flowers, trigonous capsules, and ovate leaves with basal glands, but the stamens are more numerous and the pollen is inaperturate (like Croton). Brasiliocroton has a stellate-rosulate indumentum like some Croton species, but its anthers are erect in bud, and the position of the pistillate flowers is anomalous in Croton. Molecular data place Brasiliocroton as the closest sister group to Croton, once Astraea has been removed from Croton and placed sister to Acidocroton and Ophellantha. Wood anatomical features support the generic status of Brasiliocroton.

Review of macroscopic features for hardwood and softwood identification and a proposal for a new character list

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 material, we review several prominent English-language publications on macroscopic wood identification in order to form a list of characters. We compile characters and organize them in the spirit of the IAWA lists for hardwood and softwood microscopic identification, present the state of the art as it exists, attempt to reconcile the different sets of definitions, characters, and character states, then present our proposed working-list. It is our intent with this publication to open an international discussion regarding the standardization of macroscopic wood identification features, and it is our hope that such a discussion can include critical works from the non-English literature. We also call for an illustrated glossary to accompany the proposed list. A standard lexicon to describe wood at the macroscopic level will simplify the preparation of identification documents and permit the ready translation of keys and other references for easy use and deployment around the world.

Micrandra inundata (Euphorbiaceae), a New Species with Unusual Wood Anatomy from Black-water River Banks in Southern Venezuela

Abstract Micrandra inundata is a distinctive new species adapted to seasonally flooded black-water river banks in southern Venezuela. Trees rarely exceed 10 m in height but have thick basal trunks composed of very lightweight wood. It has the smallest leaves and fruits of any known Micrandra species and appears to be most closely related to M. minor Benth. The botanical description is accompanied by habit photographs, line illustrations of morphological features, and photomicrographs and detailed descriptions of the wood anatomy.

BRIEF COMMENTS ON THE NOMENCLATURE OF SOFTWOOD AXIAL RESIN CANALS AND THEIR ASSOCIATED CELLS

The terminology related to axial resin canals in conifers is briefly reviewed, standard terms are clarified and a new term is proposed. The definitions proposed are intended primarily for light microscopic observations. All the cells and spaces of an axial resin canal as differentiated from the axial tracheids are collectively referred to as the resin canal complex. The resin canal is the intercellular space itself, and the epithelium is the uniseriate layer of cells lining the canal. We propose the term subsidiary cells to include all cells exterior to the epithelium, which may be subsidiary parenchyma and /or strand tracheids.

A new Lightweight-wooded Species of Anaxagorea (Annonaceae) from Flooded Black-water Shrublands in Southern Venezuela

Anaxagorea inundata P. E. Berry & R. B. Miller is a distinctive new species from the black- water Rio Atabapo basin in southern Venezuela. It is adapted to its strongly flooded habitat by producing very lightweight wood (specific gravity <0.2) and just a few leaves and flowers near the tips of the un- branched or few-branched stems. It appears to be most closely related to A. rheophytica Maas & Westra, also from a black-water river in southern Venezuela. An illustration of morphological features and photomicro- graphs of the wood anatomy are provided.

‘Treasures… of black wood, brilliantly polished’: five examples of Taíno sculpture from the tenth–sixteenth century Caribbean

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 tenth century AD, and suggests that some objects were treasured and refurbished over centuries. The authors discuss the symbolic properties of the wood and the long-lived biographies of some iconic sculptures.

NIRS IDENTIFICATION OF SWIETENIA MACROPHYLLA IS ROBUST ACROSS SPECIMENS FROM 27 COUNTRIES

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 (crabwood), Cedrela odorata (cedar or cedro) and Micropholis melinoniana (curupixa) have been successfully discriminated using NIRS and Partial Least Squares for Discriminant Analysis using solid block and milled samples. Species identification models identified 155 samples of S. macrophylla from 27 countries with a correct classification rate higher than 96.8%. For these specimens, the NIRS spectrum variation was more powerful for species identification than for determining provenance of S. macrophylla at the country level.

Ray-intRusive laticifeRs in species of Croton section CyClostigma (euphoRbiaceae)

SummAry A description of the occurrence and structure of “ray-intrusive” laticifers in the rays of species of Croton section Cyclostigma is provided. The systematic significance of laticifers within Croton section Cyclostigma is briefly discussed in relation to the section’s known production of red latex, commonly called “dragon’s blood”. A developmental hypothesis is offered and discussed in the context of the assumption that all laticifers in wood rays are non-articulated.