Val Ferret, Courmayeur - Caltha palustris L.
The island of Alborán lies in the middle of the Alborán Sea (Mediterranean Sea, South Spain) and is characterised by high mean temperatures and scarce precipitation. Its botanical importance led the authors yo analyse the floristic changes occurred through the XIX and XX centuries as related to the increased human pressure on the Isle, as well as to elucidate the significant environmental variables causing the observed vegetation patterns by analysing published relevès. It can be concluded that the flora of this island has been dramatically affected by temporary or permanent human presence: some species have come into extinction while others have been progressively introduced into the island as newcomers -in our visits to the island five neophytes have been recorded-. Despite the low species richness of the area, historically the island has harboured four endemic taxa: Anacyclus alboranensis, Senecio alboranicus, Frankenia corymbosa subsp. alboranensis and Diplotaxis siettiana, although the latter species is practically extinct in the wild nowadays. Man-disturbance and, to a lesser extent, edaphic salts content are probably the environmental parameters influencing the most the species distribution and floristic composition of the island plant communities. Consequently, disappearance of some particular
neophytes, man-disturbance, habitats changes, extinction, ruderal species, halophily, psammophily