Landscape changes in a Mediterranean Island.

The Mediterranean region is a major hotspot of biodiversity. However, over the last 50 to 100 years, this area has suffered dramatic changes in human pressure that has led to significant landscape changes resulting in a recovery of the vegetation cover to one of higher biomass. A multi-temporal vegetation analysis of Giannutri Island, based on inspection of a 50-year series of vegetation maps (1958–2008), shows an increase in high maquis and Juniperus-thickets positively correlated with a decrease in open and low maquis. The increase of high maquis and Juniperus-thickets shows two distinct types of strategies in their advancement: the first increases its coverage with new patches arising some distance away from one another, while Juniperusthickets expand from the margins. These two behaviour types may be correlated to a different pressure from thrushes (Turdus spp.) their disperser found on the island. The few patches of Quercus ilex woodland have remained constant due to the absence in Giannutri of its principal disperser: the jay (Garrulus glandarius). Based on this it would be impossible to take into consideration the Potential Natural Vegetation (PNV) concept in addressing conservation activities on an island like Giannutri.