Comparison of native and alien plant traits in Mediterranean coastal dunes

This study is part of a general project to analyse the biological and ecological mechanisms that influence the invasion of Mediterranean sand dune ecosystems by alien plants. In this paper we analyse the morphological and functional traits of coastal dune wild species (natives and aliens) based mainly on information from the literature. The most common 130 wild species occurring on the recent (Holocenic) coastal dunes were included considering the invasive status of alien plants. A comparative analysis of functional groups was performed through ordination techniques (PCoA using the Gower index). This reveals four functional groups related to the most important plant communities in coastal vegetation zonation. Alien plants were found in all functional groups and no trait or set of traits was specifically related to them. This indicates that aliens show similar traits to those natives growing in different communities of the coastal dune zonation, from the small beach annuals to the evergreen taller shrubs of the Mediterranean macchia. When the invasive status of alien species was taken into account, however, some differences emerged: a) casual aliens were found in almost all groups but their traits were not interpreted as being due to any particular adaptive strategy; b) naturalised aliens were only found in the less fluctuating habitats of the inner coastal zones; c) invasive alien species were connected with two major plant strategies: annual invasive aliens (quick-to-mature low grasses and herbs) and perennial invasive aliens (taller and often strongly clonal)

Malcolmia littorea: the isolated italian population in the European context

We compared the coenological information of the only Italian population of Malcolmia littorea (L.) R. Br. with published phytosociological relevés, including ones of this species, throughout its European range. With the aim of highlighting the main climatic features influencing the distribution patterns of M. littorea, we integrated coenological data with some climatic variables and considered major drivers for plant distribution at the European scale. Finally, we analysed the population extent of M. littorea in Italy, in order to assess its conservation status at regional level. The DCA analysis, performed on a matrix 139 relevés ×183 species, separated the relevés according to their floristic composition, showing a geographic gradient from Portugal to Mediterranean coasts, until Italy; with Mediterranean relevés clearly separated from Atlantic ones as well. Along the beach-inland gradient, the analysis highlights that the species is typical of fixed dunes habitats (more inland, mainly stabilised dunes), although in the Atlantic it can also be found in mobile dunes. The analysis of climatic variables in relation to M. littorea distribution, suggested that the species is sensitive to low winter temperature and to summer drought. The only Italian population of M. littorea is subjected to many threats, due to its small dimensions (<1 ha), isolation from the rest of its distribution area, that ranges from Portugal to France (until the Camargue region) and intensive human disturbances. Using both field and remote sensing information, we showed a considerable decrease of the occupied surface in Italy, leading us to suggest that the IUCN threat category of M. littorea in Italy should be reassessed from endangered to critically endangered

Il censimento della flora vascolare degli ambienti dunali costieri dell'Italia centrale.

Sampling the vascular flora in coastal dune ecosystems of Central Italy. This study examined the current distribution of the wild species growing on coastal dunes in central Italy (Lazio, Abruzzo and Molise Regions). The floristic sampling was carried out following the European Cartographic Project protocol. Major trends in wild plant distribution in coastal dunes were identified, furthermore life form and chorological spectra were shown. High floristic diversity with consistent numbers of non-native species were found. Finally, differences between the Tyrrhenian and the Adriatic coast were described

Specie vegetali esotiche negli ambienti costieri sabbiosi di alcune regioni dell’Italia Centrale

Mediterranean coastal dunes are affected by high levels of human disturbance, particularly in the last years. Disturbance not only promotes a physical alteration that increase the invasibility of coastal dunes, but also allows the arrival of new alien plant propagules. This study examined the current distribution of the alien species growing on recent (Holocenic) coastal dunes in central Italy (Latium, Abruzzo and Molise regions), considering alien origin, invasive status and growth form strategies. The floristic sampling was carried out following the European Cartographic Project protocol and 91 quadrants were examined. Consistent numbers of non-native species and clear differences between the Tyrrhenian and the Adriatic coast were found. America represented the continent which provides the highest number of aliens species. However, higher values of alien species coming from the Tropical America and Africa were found in the Thyrrenian coast, while higher values of aliens coming from the Extra- Tropical America and Eurasia were found in the Adriatic coast. Most alien species were casuals while the number of invasive aliens was relatively much lower. Finally, the success of invasive aliens appeared to be related to both annual or perennial evergreen strategies