Algerian and Tunisian coasts host more than one hundred small islands and islets, but are
still poorly known. We have compiled recently published and unpublished data from “PIM
initiative” (Mediterranean small island initiative) and other kind of expeditions. For each
small island or archipelago we seek to establish the membership to or relationship with the
regional hotspots of the Mediterranean basin and the important plant areas (IPA) of Algeria
and Tunisia, thanks to species-area relationships and biogeographical analyses. Nowadays,
25 small islands are considered as botanically well-known and can be analysed. Species-area
relationship follows a classical linear regression model while some islands are less rich than
predicted and other ones are more rich. These richest islands can be assessed as IPA following
criterion B. Some of them have been yet assessed as IPA following criterion A, especially
because of presence of local or regional endemism. Each main archipelago shows biogeographical
links not only with neighbour continental coasts, but also with northern coasts or
big islands from the western Mediterranean, especially the Tyrrhenian complex. “Grand Cavallo”
and “Petit Cavallo” islands are highlighted here as the 23rd IPA from Algeria. As biodiversity
hotchpotch, each small island or archipelago should play a significant role in the
conservation programs although some of them are still unexplored and a deeper taxonomical
knowledge is necessary in the north-African context.
