Contributo alla conoscenza della vegetazione ruderale: delle aree archeologiche romane (Roma)

Contribution to the knowledge of Roman archaeological areas (Rome). The vegetation of the main archaeological sites of Rome is analysed, taking into account the coenological characters in relation to microenviromental and anthropic factors (mowing, chemical weed killing and stamping). The phytosociological analysis allowed to the identification of 34 coenosis which represent over the 30% of communities described for whole city. The most of communities belong to Stellarietea, Artemisietea and Polygono-Poetea classes. Some associations (Dauco-Picridetum hieracioidis, Sinapidetum albae, Trifolio-Hypochoeridetum achyrophori, Saxifrago-Hypochoeridetum achyrophori erophiletosum praecocis, Valerianello-Cerastietum glomerati, Nasturtietum officinalis, Paspalo-Agrostidetum semiverticillatae and Pistacio-Rhamnetum alaterni) are very rare or not indicated for the Roman area. The coenological peculiarity and richness underline the important role of archaeological sites as refuge of natural vegetation in the urban ecosystem.