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The protection effects on floristic diversity in a North African pseudo-savanna

Sâad Ouled Dhaou^1*, Fethia Abdallah^1*, Azaeiz Ouled Belgacem² and Mohamed Chaieb¹

Abstract: A study was carried out in northern Africa to investigate vegetation in Bou Hedma National Park 13 years after it was completely protected from livestock grazing and other anthropogenic activities which have largely depleted the vegetation. This vegetation was compared with that in seriously overgrazed area outside the park, where negative influences persist.

Thirteen years of protection against grazing and human impacts of the vegetation in the pseudo-savanna of North Africa has lead to an increase of 58.30% in the total cover, 21.7% in plant density, 7% in the species richness and 9.5% in species diversity. Many of the species with significantly higher abundance in the protected area are important forage (Stipagrostis ciliata, Stipagrostis plumosa, Cenchrus ciliaris and Argyrolobium uniflorum) and/or fuel plants (Gymnocarpos decander and Hammada schmittiana). Soil nutrients (N, K, Na and Mg) are significantly higher in the protected area witch may be attributable to the degradation of the soil surface in the free grazed area.

¹ Sfax Faculty of Sciences, Laboratory of Plant Biology and Ecophysiology in Arid Land, University of Sfax, 3018 Sfax, Tunisia.

² Arid Region Institute, 4119 Medenine, Tunisia.