Wood and Charcoal Anatomy of Four Myrtaceae Species

Abstract

Qualitative and quantitative changes in anatomical characteristics of charcoal from Campomanesia xanthocarpa, Eugenia pyriformis, Myrcia retorta and Plinia peruviana were described to provide its correct discrimination and information's to contribute to evaluations in illegal logging. The material came from Planalto Catarinense region, southern Brazil. For each species, three discs at diameter at breast height were collected from three randomly selected trees. All the disks were sectioned to obtain samples in different positions of the trunk (bark, intermediate and pith). Samples were wrapped in aluminum foil and carbonized in a muffl e furnace, with a fi nal temperature of 450 °C and a heating rate of 1.66 °C. min-1. In species analyzed, growth rings are few distinct, delimitated by fi ber regions; solitary vessel and axial parenchyma diffuse or diffuse-in-aggregate is predominant. The wood to charcoal conversion caused variation in the following characteristics: vessel diameters decreased varying from 21.1% in Myrcia retorta to 33.4% in Eugenia pyriformis, while the vessel frequency increased with values from 50.7% to 92.3% related to the same species; height and width of the rays showed reduction, however, Myrcia retorta presented ruptures in ray cells and dimensions increased; ray frequency increased from 3.9% in Eugenia pyriformis to 54.1% in Campomanesia xantocharpa. Qualitative characteristics of wood from studied species remained in charcoal after carbonization at 450 ºC, being possible to discriminate the material based on wood anatomy. In charcoal, vessels dimensions and frequency, after ray characteristics can be applied as fi rst step in this Myrtaceae species distinction at forest control.

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

“…Results related to changes in ray height are associated with species characteristics, as also reported by Nisgoski et al [28] for Ocotea porosa in carbonization programs with final temperature varying from 350 to 650 °C, and in carbonization process with temperature of 450 °C by Nisgoski et al [32] and Stange et al [31]. In other Mozambican species, in the same carbonization parameters of this study, Nisgoski et al [18] described decrease in ray height in Sterculia quinqueloba from 60 to 37% (P2-P4) and in other species verified increase in P1 and decrease in P2.…”

“…The main component that acts in the formation of charcoal is lignin, since it is technically more stable than the carbohydrates of wood. The literature reports, in some carbonization procedures with temperature of 450 °C, an increase in ray frequency, decrease and no statistical changes [16,31,32]. In the same carbonization parameters of this study, Nisgoski et al [18] related increase of 88% (Sterculia quinqueloba-P2) and a reduction of 16% (Bobgunnia madagascariensis-P1) in ray frequency.…”

“…Generally, if carbonization parameters cause vessels to contract, their frequency increases, as observed in this study, but it is also related to species intrinsic characteristics. 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].…”

Effect of carbonization on wood anatomy of three Fabaceae species from an Araucaria forest stand in Southern Brazil

“…Reduction in vessel diameter after carbonization is related to anatomical features, such as the wall thickness of fibers and disposition of axial parenchyma cells, as well as processing conditions such as heating rate. These changes were also reported in other species, such as four Myrtaceae species (Stange et al 2018), in angelim species (Muñiz et al 2016) and other species from the Fabaceae family (Nisgoski et al 2012). Another factor that can influence vessel diameter is the possible change in circular shape of cells after carbonization (Gasson et al 2017).…”

“…In other species, there were no differences based on radial position. In a study with Myrtaceae species, Stange et al (2018) also verified that changes in vessel density were not linear regarding position and oc-curred in accordance with species. Carbonization had little influence on vessel density.…”