Potential of the near-infrared spectroscopy for the discrimination of wood and charcoal of four native Myrtaceae species in southern Brazil

Abstract

ABSTRACT Because of the species similarity and the need to differentiate wood of the Myrtaceae family, this study aimed to evaluate the potential of near-infrared spectroscopy for discrimination of wood and charcoal from Campomanesia xanthocarpa Berg, Eugenia pyriformis Cambess., Myrcia retorta Cambess. and Plinia peruviana (Poir.) Govaerts, native of the Araucaria Forest. For each evaluated species, three trees were collected and a disk at breast height was cut and divided into samples obtained in the region near the pith, intermediate and near the bark. For each sample, two spectra were obtained in each anatomical section (transversal, radial and tangential) in the region from 4000 to 10,000 cm−1. Results indicated the similarity of wood and charcoal spectra of all species, and principal component analysis (PCA) of raw data on samples showed little distinction of species, but second derivative pretreatment provided adequate discrimination. When evaluation was based on anatomical sections and position in trunk, for wood in all positions (near bark, intermediate, near pith) it was possible to separate species, but for charcoal some more samples dispersion were observed. Linear discriminant analysis corroborated the results of PCA. Near-infrared spectroscopy presented adequate results and the potential to help discriminate wood and charcoal of the four Myrtaceae species.