Impact of Heart Rot of Pericopsis elata (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 Societe d'Exploitation Forestiere 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.