Comparative study of the diameter structure of Pterocarpus soyauxii Taub. (Fabaceae) in the permanent subplots of the Yoko Forest Reserve and the Biaro Forest (Ubundu, Democratic Republic of Congo)

Study of diameter structure of Pterocarpus soyauxii Taub species has been undertaken in Yoko Forest Reserve and Biaro Forest into two permanent dispositive of 400 ha each one. This work has objectives based on density distribution by diameter class and pedological parameters in the two selected sites. All stems of dbh ≥ 10 cm of the studied species have been inventoried, measured through 40 bands of 10 ha each one and soil samples were also collected in the two sites. 1051 trees were indexed with 663 inventoried in Biaro forest. This one present a good reconstitution of stems species for having many individuals into inferior diameters classes. The results of the pedological analyses showed that the two sites have an acid soil.