Conclusion generale.

Abstract EN

ECOLOGICAL AND FORESTRY STUDY OF CEDAR FORESTS IN THE RIF MOUNTAINS (MOROCCO).

A DISSERTATION ON APPLICATION OF THE MULTIVARIATE DATA ANALYSIS TO THE PHYTO-ECOLOGY AND THE PRODUCTIVITY OF CEDRUS ATLANTICA MANETTI.

The dissertation comprises five parts.In each of them, it is attempted to advance,in a simultaneous way, the knowledge of the phenomena in question : ecology and productivity of the Atlas cedar and their study by multivariate analysis methods.

The climatological outline upon the whole of the cedar forests of the boundaries of the Mediterranean enables us to deal more accurately with the genecological variability of the species and to emphasize the bioclimatological types of the cedar forests in the Rif mountains .

The critical analysis of the different ways used for the study of the forest environment leads to present a methodology,on the conceptual level and on the level of the multivariate analysis .

This methodology is used for the identification and description of the plant communities of the cedar forests in the Rif.The morphometric characterization of the stem form allows the construction of accurate and reliable volume tables for forest yield assessment.

The results obtained , as to ecology and forest mensuration, lead to an approach of the determination of the relationships between site and yield , which give an identification of the growth classes.