Evolution of Floristic Composition and Structural Parameters between Two Management Inventories in a Tropical Forest in the East Cameroon Region

The realization of two management inventories in 2003 and 2020 on the same forest concession made it possible to characterize the floristic composition and to describe some structural parameters on three sites established according to the period of exploitation. Due to the change in the orientation of the lines, it was noted that respectively 82 and 85 species from the first inventory are not found in the second and inversely. A total of 311 species were identified in 2003, compared to 314 in 2020. The density varies from 111 to 140 stems/ha for all the individuals, 19 to 25 for the main species and 15 to 20 for the most exploited species. The decrease in the basal area between the two phases of 12% for all the species and 13% for the main species on the site exploited before the first inventory indicates a persistence of the disturbance for years after logging. It is proposed to supplement the management plans decisions with annual measures based on more complete inventories and to ensure the application of reduced impact logging measures.

Impact of Heart Rot of <i>Pericopsis elata</i>(Harms) Van Meeuwen on Yield at Harvest in Production Forests in South-Eastern Cameroon

This study of the impact of heart rot of Pericopsis elata on logging yield was conducted in Libongo, in three logging concessions of the Société d'Exploitation Forestière et Agricole du Cameroun (SEFAC). An inventory of 92 P. elata stumps in four Annual Cutting Areas (AACs) divided among three Forest Management Units (FMUs) distinguished by Minimum Operating Diameter (MOD) revealed that 22 stumps were rotten. Decay was visible on stumps with a diameter of more than 100 cm with a frequency of occurrence of 23.91%, a percentage of abandonment of 55.20% and a yield of 44.79%. The most important economic loss was revealed on 9 abandoned whole logs that cumulated a volume of 145.547 m3. The correlation between the diameter of the stumps and that of the decay gives a coefficient or correlation rate r = 0.31. The MOD for P. elata could be 80 cm and covers the biological risk class. The results indicate that P. elata shows an increasing gradient of decay rate with increasing tree diameter, resulting in a loss of material for larger diameter trees, and consequently a decrease in material yield at processing.