Highlighting a New Morphospecies within the Dialium Genus Using Leaves and Wood Traits

Abstract

During inventories of lesser-known timber species in eastern Gabon, a new Dialium morphospecies was discovered. To discriminate it from the two other 2–5 leaflets Dialium species, 25 leaf traits were measured on 45 trees (16 Dialium pachyphyllum, 14 Dialium lopense, 15 Dialium sp. nov.). Nine wood chemical traits, as well as infrared spectra, were also examined on harvestable trees (four Dialium pachyphyllum and four Dialium sp. nov.). This study revealed seven discriminant leaf traits that allowed to create a field identification key. Nine significant differences (five in sapwood and four in heartwood) in terms of wood composition were highlighted. The use of the PLS-DA technique on FT-IR wood spectra allowed to accurately identify the new morphospecies. These results provide strong support for describing a new species in this genus. Implications for sustainable management of its populations are also discussed.

The Diversity of Wood and Non-Wood Forest Products: Anatomical, Physical, and Chemical Properties, and Potential Applications

“…In the tropical forests of Gabon, a new morphospecies within the Dialium genus was introduced for the first time and studied by Doucet et al [5], focusing on its discriminant leaf and wood composition traits. Since a limited number of timber species are presently used, the newly presented species, as well as other species such as Dialium pachyphyllum Harms and Dialium lopense Breteler, are important alternative species [5]. However, the authors mention the to implement strategies for the sustainable wood production and conservation of these species.…”