Wood anatomical and topochemical analyses to characterize juvenile and adult wood of lesser-known species from Central America (Mexico)

Anatomical and subcellular characteristics of juvenile and adult wood of seven species (Manilkara zapota (L.) P. Royen, Platymiscium yucatanum Standl., Lonchocarpus castilloi Standl., Roseodendron donnell-smithii (Rose) Miranda, Terminalia buceras (L.) Wright, Tabebuia rosea (Bertol.) DC., Lysiloma latisiliquum (L.) Benth. from Mexico, including a histometric evaluation, were investigated by light microscopy with a digitized image analysis system and by X-ray diffractometry using the SilviScan® system. The topochemical distribution of lignin and phenolic deposits in the tissue was studied by means of cellular UV-microspectrophotometry (UMSP). Extractive contents (acetone/water and water) were determined gravimetrically. The results of the structural and topochemical analyses were compared with the interrelations of certain anatomical and subcellular structures as well as the topochemical composition with regard to the physical and mechanical properties of the timbers investigated. The objective was to provide a detailed cellular and subcellular description of the heartwood of seven lesser-known timbers from Central America. All examined tree species show significant differences between juvenile and adult heartwood. For individual species, however, the differences vary greatly and have to be individually assessed in addition to general trends observed for all studied species. It has been shown that vessel size, fibre length, size of fibre lumina, and height and width of rays, as well as the content of extractives and topochemical composition of the cell walls, are suitable indicators for the differentiation of the two heartwood types. The results also contribute to a better understanding of the wood properties of the investigated timbers in relation to their utilization and added value increase.