Survey on the chemical composition of several tropical wood species

Abstract

Variability in the chemical composition of 614 species is described in a database containing measurements of wood polymers (cellulose, lignin and pentosan), as well as overall extraneous components (ethanol-benzene, or hot water extracts and ash, with a focus on silica content). These measurements were taken between 1945 and 1990 using the same standard protocol. In all, 1,194 trees belonging to 614 species, 358 genera and 89 families were measured. At species level, variability (quantified by the coefficient of variation) was rather high for density (27%), much lower for lignin and cellulose (14% and 10%) and much higher for ethanol/benzene extractives, hot water extractives and ash content (81%, 60% and 76%). Considering trees with at least five different specimens, and species with at least 10 different trees, it was possible to investigate within-tree and within-species variability. Large differences were found between trees of a given species for extraneous components, and more than one tree should be needed per species. For density, lignin, pentosan and cellulose, the distribution of values was nearly symmetrical, with mean values of 720 kg/m3 for density, 29.1% for lignin, 15.8% for pentosan, and 42.4% for cellulose. There were clear differences between species for lignin content. For extraneous components, the distribution was very dissymmetrical, with a minority of woods rich in this component composing the high value tail. A high value for any extraneous component, even in only one tree, is sufficient to classify the species in respect of that component. Siliceous woods identified by silica bodies in anatomy have a very high silica content and only those species deserve a silica study.

Physico-mechanical properties of the wood of freijó, Cordia goeldiana (Boraginacea), produced in a multi-stratified agroforestry system in the southwestern Amazon

“…The chemical composition of the freijó wood was in accordance with tropical hardwoods (Gérard et al 2019;Qiu et al 2019). Similar content levels were observed in 25-30-year old freijó wood from natural forests, except for higher levels of holocellulose (78%) and extractives (7%) (Scatolino et al 2017).…”

Influence of Sahelian and Sudanian provenances on the physical and mechanical properties of Faidherbia albida wood from Chad

“…albida also had a very high extractive content, although it was lower than that of vène. The CIRAD wood database (Gérard et al 2019) also gives a total extractive content of 8.6% for a Senegalese provenance, and 17.2% for vène from Senegal, while the results reported by Traoré (2009) indicated total extractive contents of between 15.5% and 19.5%.…”

Termiticidal activity of oil from Jatropha curcas L. and Azadirachta indica A. Juss against Coptotermes sjostedti Holmgren (Isoptera: Rhinotermitidae)

“…Woods are known to differ in their susceptibility to termite attack; these differences may be attributed to factors such as chemical composition, wood density and availability of susceptible species (Jambere et al 1995;Gérard et al 2019). However, all the woods tested showed significant susceptibility to C. sjostedti attacks.…”