The impact of human trampling on a threatened coastal Mediterranean plant: The case of Anchusa littorea Moris (Boraginaceae)

In a 5-period study (2007–2011) we examined the effects of human trampling on the last remaining population of Anchusa littorea on its sandy coastal habitat in Sardinia. This species, considered extinct in the wild for several years, was casually rediscovered in a small population at Is Arenas (SW Sardinia). We monthly monitored six trampled and six un-trampled permanent plots, mapping individuals and recording their size and reproductive variables. Trampled and un-trampled plots showed significant differences with respect to plant density, plant size and reproductive performance (flowers and fruits production) of A. littorea. This study demonstrated that human trampling represents a severe threat to the conservation of this species that can be appreciated as a keystone species with concern to human trampling effects on coastal dune plants. In case of A. littorea urgent measures should be undertaken to protect this unique remnant population in the dune system of Is Arenas. In particular, tourist paths should be redirected and confined to others areas in order to promote the natural expansion of A. littorea in its original habitat. A possible integrated strategy for the conservation and management of the species consists in a combination of in situ and ex situ measures.