Preliminary essay on the chorology of the Iberian gypsicolous flora: rarity and richness of the gypsum outcrops

The Iberian aljezares have been recognized as areas of high phytodiversity and endemism as they harbour an extremely peculiar flora. Mining activities can endanger this flora. It is necessary to indicate the most important areas in order to conserve the biodiversity, so the chorology of 53 gypsophytes taxa have been developed where 1 was used for presences of every taxon and 0 for absences in UTM cells of 10 x 10 km(2). This chorology is a complex dataset including numerous local endemics and high territorial differences (high beta-diversity). In addition, the results indicate that the richest aljezares are present in the Central Iberian Meseta (plateau), while the highest values of rarity are situated in the semiarid South East of the Iberian Peninsula.