Dynamique des groupements végétaux dans une aire protégée de Tunisie méridionale

Abstract

This study was carried out in the protected area (ZI) (5,115 hectares) of Bou Hedma National Park, a UNESCO biosphere reserve since 1977 and a sanctuary for the unique wooded steppe of Acacia tortilis subsp. raddiana in Tunisia. Two maps were elaborated and compared, one of the present ecological systems characterizing the area (situation 2003) and the other corresponding to the situation in 1963 with the former agricultural land use. The diachronic comparison of the two maps carried out using the Geographic Information System (GIS) technology showed a good establishment of the original vegetation and the expansion of some ecological systems, especially the riverine associations (the result of several recent floods). Besides, zones which were formerly occupied by field crops and tree crops have been showing, for some years, a progressive regeneration of the initial vegetation.