Mahogany is one of the most valuable woods and was widely used until it was included in Appendix II of the Convention on International Trade in Endangered Species as endangered species. Mahogany wood sometimes is traded under different names. Also, some similar woods belonging to the Meliaceae family are traded as “mahogany” or as being of a “mahogany pattern”. To investigate the feasibility of the use of near infrared spectroscopy for wood discrimination, the mahogany (Swietenia macrophylla King.), andiroba or crabwood (Carapa guianensis Aubl.), cedar (Cedrela odorata L.), and curupixá (Micropholis melinoniana Pierre) woods were examined. Four discrimination models based on partial least squares-discriminant analysis were developed based on a calibration set composed of 88 samples and a test set with 44 samples. Each model corresponds to the discrimination of a wood species from the others. Optimization of the model was performed by means of the OPUS® software followed by statistical analysis software (Matlab®). The observed root mean square errors of predictions were 0.14, 0.09, 0.12, and 0.06 for discriminations of mahogany, cedar, andiroba, and curupixá, respectively. The separations of the species obtained based on the difference in the predicted values was at least 0.38. This makes it possible to perform safe discriminations with a very low probability of misclassifying a sample. This method can be considered accurate and fast.

The bark anatomy of28 species of arborescent Leguminosae of 'cerrado' and gallery forest in the Brazilian Federal District was examined. The most significant characteristics for taxonomic purposes were determined to be: delimitation between collapsed and non-collapsed phloem; phloem stratification; type and position of sieve plates; dilatation patterns; arrangement and contents of sc1ereids; and presence of secretory cells. The bark data support the idea that Papilionoideae is the most advanced group of the Leguminosae.

AMAZONIAN WOOD SPECIES. Supervising wood exploitation can be very challenging due to the existence of many similar species and the reduced number of wood identification experts to meet the demand. There is evidence that valuable endangered wood species are being smuggled disguised as other species. Near infrared spectroscopy (NIRS) and chemometrics has been successfully used to discriminate between Amazonian wood species using high resolution instruments. In this study, a handheld spectrometer was evaluated for the discrimination of six visually similar tropical wood species using PLS-DA. Woods of mahogany (Swietenia macrophylla) and cedar (Cedrela odorata), both high value tropical timber species included in Appendixes II and III of the CITES, respectively; crabwood (Carapa guianensis); cedrinho (Erisma uncinatum); curupixá (Micropholis melinoniana); and jatobá (Hymenea coubaril). The data for model development and validation take into account both laboratory and field measurements. Outlier exclusion was performed based on Hotelling T 2 , residuals Q and errors in the estimated class values. The efficiency rates were higher than 90% for all species, showing that the handheld NIR combined with PLS-DA succeeded in discriminate between these species. These results stimulate the application of handheld NIR spectrometers in the supervision of wood exploitation, which can contribute to the species preservation.Keywords: mahogany; cedar; crabwood; NIR; PLS-DA; amazon woods. INTRODUÇÃOA exploração e comercialização de madeiras ilegais contribuem para o crescimento contínuo das taxas de desmatamento das florestas Amazônica e demais do globo terrestre. Atualmente, há um esforço de várias instituições internacionais para combater a exportação de madeira ilegal, que envolve cifras da ordem de bilhões de dólares anuais, respeitando a legislação existente em cada país. Tal esforço tem como finalidades controlar, proibir ou desmotivar a exploração seletiva de espécies florestais produtoras de madeira ou de uma área específica explorada. 1 Apesar de todo o empenho, existe carência em resolver uma questão básica e primordial, a de identificar rapidamente e de maneira confiável, a qual espécie florestal pertence a madeira que está sendo inspecionada. Para a identificação da madeira, geralmente desprovida de qualquer material botânico, da forma como ela é transportada e comercializada, fiscais e agentes ambientais treinados recorrem ao método convencional de anatomia de madeira, que compara os caracteres anatômicos e morfológicos da madeira examinada com a madeira de padrões depositados em xilotecas registradas.2 As chaves de identificação, eletrônicas ou não, reúnem informações anatômica e física da madeira e facilitam a análise anatômica.3 Contudo, ainda é necessária elevada experiência do analista para a aplicação do método com o nível de confiança necessário para realizar uma apreensão de carga ilegal. Adicionalmente, apesar dos ótimos resultados apresentados pelo método anatômico, em muitas regiões e postos de fiscalização n...

The objectives of the present study were to determine anatomical characteristics, mechanical properties and natural durability to two fungi types [Gloeophyllum trabeum (Persoon ex Fries) Murrill and Trametes versicolor (Linnaeus ex Fries)Pilat] for cypress wood (Cupressus spp.). The wood has straight grain, brown to white color, medium texture, and moderate luster. It also showed medium to low density, low shrinkage, and moderate dimensional stability. Lignin content was relatively high, whereas extractive content was low. Cupressus spp. showed static bending properties of 4.1 GPa for modulus of elasticity; 91.0 MPa for modulus of rupture; 1.8 MPa for internal bond; and 6357 and 4039 N for end and side Janka hardness, respectively. All mechanical properties, in air-dry condition, were similar to those described to cypresses and some Amazonian hardwood species. Cypress wood was ranked as highly resistant to the brown-rot fungus Gloeophyllum trabeum and to the white-rot fungus Trametes versicolor, making it suitable for interior and exterior uses and high humidity environment.

Woods from an important group of Lecythidaceae species called “tauari” can hardly be identified in the field by their gross and general features. In this study we show that, when properly delimited to the genera Allantoma, Cariniana and Couratari, wood anatomical characteristics can be used to identify the species known as “tauari”, even though it is not possible to separate all species. In addition to anatomical characters, wood colour is an important character to help distinguish species of Cariniana and Allantoma from species of Couratari. Detailed wood anatomical descriptions from “tauari” woods Allantoma, Cariniana and Couratari are given and a table with diagnostic differences is presented. Common characters of this group are axial parenchyma in narrow continuous bands, prismatic crystals in chambered axial parenchyma cells and silica bodies in ray cells. Microscopic features that help in species identification are: fibre pitting (minutely or distinctly bordered), traumatic intercellular canals, average vessel diameter, vessel element length, axial parenchyma strand length, and ray height and width.