Recent evolution of the Jbel Hebri forest (Western Middle Atlas, Morocco)

This study deals with the different aspects of forest evolution on the Jbel Hebri mountain ranges. On the basis of a comparative aerial photograph analysis (1962 and 1987 missions) completed by photogrammetry and field observations, the vegetation structure and its succession stages have been recognized. Although the total forest area remains unchanged, the physiognomic stages of identified communities (Cedrus atlantica forest; Quercus rotundifolia forest; mixed forest with Cedrus atlantica and Quercus rotundifolia) show heterogenous evolution. Depending on species and forest components we note paradoxal evolutionary tendencies. Systematic degradation due to harvesting and resource overuse is locally observed beside regenerated and densified parts. Therefore, the system dynamics reflects the locally variable factors such as soil hydrology and human impact.