Donnees sur les caracteristiques et la phenologie de l'herbier de Posidonia oceanica (L.) delile sur les cotes de Mahdia (region est de la Tunisie)

Abstract

This paper presents the results of Posidonia oceanica meadows prospecting in Mahdia coasts. The study concerns the phenology of this plant in eight stations during summer and winter. The beds of Posidonia oceanica seagrasses in Mahdia are mostly in very good condition, but we have found a poor vitality in Ben Ghayadha, Sidi Salem and Corniche. We observe also that the seasonal variation of the seagrasses is accompanied by a reduction in mean length of adult and intermediaries leaves, the increase in the mean number of intermediate leaves and the decrease of the leaf area index from summer to winter.