Habitat Suitability Assessment of the Rare Perennial Plant Armeria Arenaria (Pers.) Schult. (Plumbaginaceae) along the French Mediterranean Coastline

Abstract

A major challenge in conservation biology is to identify the factors driving abundance and demographic regeneration of rare species populations. We assess habitat suitability within a protected area for Armeria arenaria (Pers.) Schult. (Plumbaginaceae), a small perennial polycarpic plant and keystone species of a threatened plant community on the rocky crystalline coastline of South-East France. The factors associated with the occurrence and abundance of adult plants and juveniles of this species were investigated by an “Outlier Mean Index analysis” (OMI). A second census was conducted three years later to test the reliability of inferences about habitat suitability. The results underline the importance of fine scale habitat heterogeneity to understand the variation of abundance. Moreover only a portion of the habitat of Armeria arenaria is suitable for regeneration, underlying the necessity to consider both abundance and regeneration to set conservation and management priorities.