Étude de la croissance diamétrique de quatre essences de bois d’oeuvre exploitées à l’Est du Cameroun

Abstract

Objectives: This article examines the diametric growth of 4 commercial species, with poor natural regeneration, exploited in eastern Cameroon. The species are Erythrophleum suaveolens (tali), Mansonia altissima (bété), Pericopsis elata (assaméla) and Triplochiton scleroxylon (ayous). Methodology and results: For this purpose, permanent monitoring growth devices constituted by permanent circuits were installed. After 3 years of annual measurements of the tree diameter, a periodic diametric medium growth of 0.68 cm / year for E. suaveolens, 0.37 cm / year for M. altissima, 0.32 cm / year for P. elata and 0.70 cm / year for T. scleroxylon was obtained. Considering the periodic medium growth of two diameter classes below the minimum diameter for logging, a new replenishment rate for the 4 species was calculated.Conclusion and application of findings:These replenishment rates were compared to the replenishment rate obtained using the diametric growth set by the Cameroonian government. There is an overestimation of the possibilities by the administration for M. altissima and T. scleroxylon and an underestimation of the possibilities in the case of E. suaveolens. For P. elata, the replenishment rate obtained in this study permanent devices is substantially similar to those calculated with the diametric growth proposed by the Cameroonian state. The results of this study will serve as a reference to the sustainable management of species with low diametric growth by raising their minimum logging diameter. For species with low natural regeneration as those considered in this study, silvicultural measures should be proposed.Keywords: commercial timbers; management plan; diametric growth; permanent devices; replenishment rate.