Numerical syntaxonomy of badland vegetation in the Apennines (Italy)
Ferrari, C.; Gerdol, R.
Phytosociological data from badland vegetation in the Apennines are treated by numerical methods through the following steps: 1) species ranking by an information criterion ; 2) classification of species and relevés based on the reduced data set; 3) characterization of the resulting types by analysis of concentration. The following associations are recognized: 1) Artemisietum cretaceae developed on Pliocene clays in Tuscany and Romagna; 2) Cynaro-Agropyretum pungentis on Pliocene clays in Abruzzo; 3) Cardopatetum corymbosi on scaly clays in southern wet mediterranean badlands from Basilicata; 4) Anthemido-Podospermetum resedifolii on scaly clays in southern mediterranean badlands from Calabria. Some impoverished plant communities are also described: Agropyron pungens communities, on scaly clays in different regions of northern and central Italy; Hordeum maritimum community, corresponding to primitive succession stage on scaly clays of Basilicata. At high syntaxonomical levels, badlands vegetation is dominated by two phytosociologically distinct species groups: Mediterranean ruderal therophytes (class Thero-Brachypodietea) and continental stress-tolerant perennial plants (class Festuco-Puccinellietea). The inclusion of badland associations in the latter class is suggested, emphasizing the connections among salt steppe vegetation complexes in Europe. The importance of ruderal plants is interpreted as an indication that badlands constitute marginal habitats for inland halophytic vegetation.