This study provides a first step toward the knowledge of the alien-dominated and co-dominated plant communities present in Italy. The first ever checklist of the alien phytocoenoses described or reported in literature for the Italian territory has been compiled, produced by data-mining in national and local thematic literature. The resulting vegetation-type draft-list has been checked in the light of the most recent syntaxonomic documentation and updated with regards to syntaxonomy and nomenclature, with special reference to the frame proposed in the Italian Vegetation Prodrome. The list includes 27 vascular and one bryophyte vegetation classes, hosting 194 low rank alien-dominated syntaxa. The different vegetation types detected for each syntaxonomic class and macro-vegetation group, defined by physiognomical and ecological attributes, are discussed.

The objective of this study is to provide an updated conservation status of all liverworts and hornworts in the Italian territory, evaluated according to IUCN’s Guidelines for Application of IUCN Red List Criteria at Regional Level. Overall, 27.4% of taxa assessed in this study are assigned to a risk category and, therefore, considered threatened in Italy. Four liverworts are considered as Extinct, two liverworts and one hornwort Possibly Extinct at regional level. Moreover, a further 9.8% are assessed as Near Threatened, 10.8% as Data Deficient and 49.7% as Least Concern. Most threats are co-occurring, indicating that many taxa are subjected to a set of correlated adverse processes. The main IUCN major threats identified were natural system modifications (i.e., dam construction, increases in fire frequency/intensity, and water management/use), climate change (mainly increasing frequency of droughts and temperature extremes), agriculture (including pollution from agricultural effluents) and aquaculture.

A comparative analysis of the riparian vegetation dominated by Alnus glutinosa in Italy and Tyrrhenian islands, based on literature data and unpublished relevés, is presented. A total of 456 phytosociological relevés were processed. For the definition of plant communities and alliances, hierarchical clustering was performed by using Bray-Curtis coefficient and Detrended Correspondence Analysis ordination methods. Identification of diagnostic species of the vegetation units was performed by means of the phi fidelity index. Quantum GIS software version 3.6 was used for the interpolation of the bioclimatic variables and A. glutinosa communities. Overall, a total of 18 A. glutinosa-riparian wood communities were distinguished for Italy and Tyrrhenian islands, of which two new associations and one new subassassociation are described. The classification of the relevés showed two main vegetation groups: the first one including the plant communities of the Osmundo-Alnion alliance, and the other including the vegetation of the Ligustro vulgaris-Alnion glutinosae alliance. This latest includes the riparian meso-thermophilous communities of central and northern Italy. Within the Osmundo-Alnion alliance, two subgroups can be recognized: the first one includes the thermophilous communities of the Hyperico hircini-Alnenion glutinosae sub-alliance, mainly spread in the Tyrrhenian islands, while the second group includes the mesophilous communities attributed to the new suballiance Struthioptero-Alnenion glutinosae, widespread in central Italy and the Corsican mountains. The present paper provides the first comprehensive and exhaustive scheme of the A. glutinosa riparian woodlands diversity in Italy and Corsica.

The bryophyte vegetation of the coastal area of the Cilento and Vallo di Diano National Park has been investigated. The phytosociological study has emphasized the occurrence of many associations of the phytosociological classes Barbuletea unguiculatae, Pleurochaeto squarrosae-Abietinelletea abietinae, Cladonio digitatae-Lepidozietea reptantis, Grimmietea anodontis, and Frullanio dilatatae-Leucodontetea sciuroidis. Among these, Barbuletum convolutae, Didymodonto vinealis-Tortuletum muralis, and Funarietum hygrometricae show a strong human impact. On the contrary, the epiphytic associations (Syntrichietum laevipilae, Leucodonto sciuroidis-Leptodontetum smithii, and Fabronietum pusillae), as well as Tortelletum papillosissimae, Rhynchostegielletum algirianae, Tortello flavovirentis-Trichostometum crispuli, and Rhynchostegietum megapolitani, show a good degree of naturalness and air purity. This is revealed by the bryovegetational analysis based on biological and ecological parameters (life form, ratio St/We, life strategy, sensibility to air pollution and human impact) that can be interpreted to provide useful information about the quality and the health of the environment. Moreover, a new association, Gongylanthetum ericetori, is described here.