Zonation of scrubs of the Rosmarino-Ericion alliance according to climatic parameters in Aragon and Catalonia

The correspondance between the vegetation units and the different climatic condicions in certain areas of Aragon and Catalonia is analysed. Eight communities belonging to the Allliance Rosmarino-Ericion with relevant climatic features have been chosen and their cartographies have been made. A bioclimatic study is suggested: the developmental index for thermal scrubs (Ix) and that for continental scrubs (Iz). The data are shown for 46 climatic stations present in the area. The Ix index is equal or greater than 25 for Anthyllido-Cistetum cornmunities, or included between 14 and 24 for Erico Thymelaeetum cornmunities. On the other hand, the continental scrubs appear in areas with an Iz index between 25 and 40 (Genisto-Cistetum subarea) or greater than 40 (Rosmarino-Linetum subarea).