A description of the climate, geology and plant communities of the study area is presented. The result of a TWINSPAN classification of 149 releves was refined by Braun-Blanquet procedures, Eight plant communities of which one is divided into three variations, were distinguished. A hierarchical classification, ecological interpretation and vegetation map delineating the extent of the plant communities, are presented. An agro-ecological quantification of the woody vegetation was done in each plant community.