Characterization of the Biodegradation of Kasbahs of the Gharb Region (Mehdia and Kenitra Kasbahs, Morocco)

Abstract

With the aim of contributing to the solutions linked to the problems of the preventive preservation and the restoration of the Kasbah of Mehdia or the Kasbah of Moulay El Hassan, a study of the flora populating the facades of these historical monuments was realized and showed the presence of a varied and diverse vegetation populating these buildings left to the ravages of time. The inventory of this flora showed the existence of 70 species among which 48 were exclusively detected at the Kasbah of Mehdia, 11 other species were only discovered at the Kasbah of Kenitra and 11 vegetal species were inventoried at both Kasbahs. These plant species are divided into 28 families. Four families clearly dominate the flora inventoried at both Kasbahs of the Gharb region. These are the Asteraceae (15.7%), Poaceae (10%), Apiaceae (8.6%) and Scrophulariaceae (5.7%). These families alone account for 41.4% of the specific size of the flora of the studied sites. The most dominant vegetal type is the therophytes with 61.4% of the total specific size, followed by hemicryptophytes with 17.1%. Located at the top or the base of walls, these plants, fitting into joints or cracks, have a chemical action on the stones by acids which they release and also have a mechanical action on the stones by the growth of roots inside cracks. This vegetation remains one of the most important biological factors of the degradation of historical monuments.