NUMERICAL SYNTAXONOMY OF THE ASPLENIETALIA-PETRARCHAE IN THE IBERIAN PENINSULA

A numerical syntaxonomic study of rupicolous vegetation of the Aspleni etalia petrarchae in the Iberian Peninsula is described. The study is based on 37 local tables (OSUs) of different rupicolous communities fr om limestone cliffs found in the eastern half of the Iberian Peninsula . Three classification approaches were followed: (1) 'hard partition' techniques, (2) 'fuzzy partition' and (3) ordination partition. In ord er to find a direct solution, we tried an evaluation system based on t he inertia associated with a CCA, Canonical Correspondence Analysis, a nd its relationships with the inertia of a similar CA, Correspondence Analysis. The most effective solutions were found through spatial part itions, and the best partition was obtained with CA considering five s egments per axis. Among the fuzzy partitions the best solution was obt ained with two clusters and a fuzziness value of 1.20. The best hierar chical partition was Complete Linkage with Chord Distance as a resembl ance function. With the GRID procedure applied to the CA diagram, thre e different groups were distinguished. The first group is related to t he Saxifragion boisseriano-reuterani, including five OSUs from Baetic ranges; the second group is very close to the Cosentinio-Lafuenteion r otundifoliae and includes 11 OSUs from thermo-mediterranean areas; the third group, including 21 OSUs basically related to meso-mediterranea n areas, is strongly related to the Teucrion buxifolii.