Ecological magnitude and fine scale dynamics of the mediterranean narrow endemic therophyte,Arenaria provincialis(Caryophyllaceae)

In the context of plant species rarity in mediterranean ecosystems, this study aims to precise the autoecology of the local annual endemic plant, Arenaria provincialis (Caryophyllaceae), by quantifying habitat and vegetation characteristics, and demographic parameters. Its populations are surprisingly scattered along a wide altitudinal and topological range, but over small geographical distances. This implies an important habitat differentiation from the thermophilous dry coast to the colder supra—mediterranean summits in open limestone rocky habitats such as steep screes, ledges, cracks or crests. Among the 163 plant species identified in presence of A. provincialis within 100 m2 area, 92% belong to the stress Grime pole, highlighting the stressful conditions within the different habitats caused by drought, strong wind, and high thermic contrasts. Demographical surveys reveal strong spatial and temporal fluctuations.