MORTALITY OF EXOTIC SPECIES (EUCALYPTUS DEGLUPTA B., 1863, PINUS CARIBEAE M., 1851, AND GMELINA ARBOREA R., 1814) IN CELLUCAM PLANTATIONS NEAR EDEA (LITTORAL, CAMEROON) AND AT THE INSTITUT SUPERIEUR AND THE MBAIKI INSTITUTE OF RURAL DEVELOPMENT (CENTRAL AFRICAN REPUBLIC)

The study was carried out at the cellucam artificial plantation located some 15 km northeast of the town of Edea,capital of the Sanaga Maritime in the Cameroon coastal zone, and at the Higher Institute of Rural developmentmbaiki in the Central African Republic. In the plantations at both sites, three species form homogeneous blocks: Eucalyptus deglupta, Pinuscaribeae and Gmelinaarborea.These plantations were installed by the pulp and paper production company cellucam (Cellulose du Cameroun) from 1979 to 1982, and asplantations at isdr Mbaiki in the Central African Republic. The aim of the study was to assess the level of evolution of the exotic species planted in the plantations at the two sites .The following results were obtained:Exotic species densities,mean diameters, mean basal area, mortality rates and survival rates vary between plantations and sites. Mortality is very high in the cellucam plantations,while the survival rate is high in theISDR plantations.This mortality may be due to the lack of maintenance of the plantations since cellucam ceased its activities, and to the presence of herbivores in the surrounding forest,which in the absence of monitoring can destroy the young seedlings at the start of the plantation. Mortality can also be caused by microscopic fungi and soil bacteria.In the well maintained plantation of the Mbaiki Higher Institute of Rural Development (Central African Republic),mortality of planted exotic species is much lower than in the cellucam plantations.To ensure the harmonious development of exotic species,and above all to achieve reforestation objectives in a given environment,an artificial plantation requires constant maintenance.