ABSTRACT :
This work summarizes the results of the first botanical surveys leaded on 11 islands and islets surrounding the Kerkennah archipelago (South East Tunisia), during the mission of the PIM Initiative in March 2014. These micro-insular entities, with a total surface of around 450 ha, has a significant interest in terms of plant biodiversity, with 266 species or sub-species of vascular plants identified, including 257 native taxa and 9 xenophytes at least naturalized. This corresponds to 57% of the total floristic richness of the Kerkennah archipelago. 51 taxa (including 4 with an exotic origin) are today located only on the satellite islands, and several notable taxa were inventoried. Gremdi is the richest island with 187 taxa, followed by Sefnou (170 taxa) and Roumadiya (139 taxa). On the phyto-geographically point of view, a very interesting group consists of saharian plants, located at the northern limit of their range. A first analysis of the major vegetation types has also been realized.
The history of micro-island environment highlights the multi-secular impacts induced by man and his cattles, and their consequences on the current state and the dynamics of vegetation. The grazing and wood-cuting, combined with the accumulation of macro-waste and the sea level rise, represent tangible threats on the structure and dynamics of terrestrial ecosystems and biodiversity. However, the general state of conservation of the flora and vegetation on the small island and islets seems generally satisfactory, compared to the two main islands of the archipelago.
These results support the development of future designation of the small islands and islets satellites of Kerkennah archipelago as a Marine and Coastal Protected Area (MCPA), and even an enhanced protection for some of the satellite islands. Indeed, these territories could play a key-role in a strategy of preservation of coastal biodiversity across the Gulf of Gabes.