Charcoal anatomy of Brazilian species. I. Anacardiaceae

Abstract

Anthracological studies are firmly advancing in the tropics during the last decades. The theoretical and methodological bases of the discipline are well established. Yet, there is a strong demand for comparative reference material, seeking for an improvement in the precision of taxonomic determination, both in palaeoecological and palaeoethnobotanical studies and to help preventing illegal charcoal production. This work presents descriptions of charcoal anatomy of eleven Anacardiaceae species from six genera native to Brazil (Anacardium occidentale, Anacardium parvifolium, Astronium graveolens, Astronium lecointei, Lithrea molleoides, Schinus terebenthifolius, Spondias mombin, Spondias purpurea, Spondias tuberosa, Tapirira guianensis, and Tapirira obtusa). They are characterized by diffuse-porous wood, vessels solitary and in multiples, tyloses and spiral thickenings sometimes present; simple perforation plates, alternate intervessel pits, rounded vessel-ray pits with much reduced borders to apparently simple; parenchyma paratracheal scanty to vasicentric; heterocellular rays, some with radial canals and crystals; septate fibres with simple pits. These results are quite similar to previous wood anatomical descriptions of the same species or genera. Yet, charcoal identification is more effective when unknown samples are compared to charred extant equivalents, instead of to wood slides.

Charcoal anatomy and NIR spectra of Spirostachys africana, Terminalia sp. and Colophospermum mopane in different carbonization process

“…Gonçalves et al [22], observed no significant changes in vessel frequency and Stange et al [31] verified increased vessel frequencies of 92% in Eugenia pyriformis and 51% in Myrcia retorta. The impact of species is closely related with the vessels' performance, as can be noted in previous studies and as described by Gonçalves and Scheel-Ybert [11]. Nisgoski et al [18] verified no linear relation from vessel frequency and different parameters of carbonization, being the intrinsic characteristics of species more important in this analysis.…”

“…The anatomical features of wood remain largely intact after carbonization, so even though some changes are observed in parenchyma, vessels and fibers [10], identification can still be accomplished based on species anatomical characteristics, principally comparing with a database [11]. Also, application of near infrared spectroscopy (NIR) has been evaluated.…”

Wood and Charcoal Anatomy of Four Myrtaceae Species

“…Changes in vessel frequency after carbonization process were commented in other studies: Nisgoski et al (2014) evaluating samples of Ocotea porosa in different final temperatures in carbonization process observed no direct relation between decrease in vessel diameter and increase in vessel frequency. Other studies with forest species (Muñiz et al, 2012b;Nisgoski et al, 2012), angelim species (Muñiz et al, 2016) and Anacardiaceae species (Gonçalves and Scheel-Ybert, 2016) also showed the influence of species characteristics in changes in vessel frequency, as thickness of fiber wall and disposition of parenchyma cells.…”

“…Changes in cell dimensions after carbonization process are described in literature as a response of anatomical and chemical composition of wood species and also process characteristics (heating rate, final temperature and total time), but qualitative information remains and can be applied in species identification (Nisgoski et al, 2014;Muñiz et al, 2016;Gasson et al, 2017). In general, tangential diameter of vessel presents reduction and its frequency an increase (Gonçalves et al, 2012 but are not linear and are related to species characteristics as fiber cell wall and parenchyma distribution (Gonçalves and Scheel-Ybert, 2016).…”

Potential of Texture Analysis for Charcoal Classification

“…In an attempt to tackle this issue, much research has been conducted aiming at characterizing the charcoals from different species and dispensing a subsidy for recognition from the anatomy (Muñiz et al, 2012a, b;Nisgoski et al, 2012;Gonçalves et al, 2012Gonçalves et al, , 2014Gonçalves & Scheel-Ybert, 2016;Muñiz et al, 2016;and Scheel-Ybert & Gonçalves, 2017). However, only a few research works have sought innovations that will facilitate recognition of species through charcoal compared with the number of innovations being proposed for the recognition through wood.…”