The riparian vegetation of Pioverna river (Lecco, Italy): preliminary analysis

This research was performed as part of a cooperation agreement between Lombardy Region and the University of Milan to provide scientific support for the river maintenance of the territory and the management of riparian vegetation. To obtain information about river vegetation for management purposes, it is important to understand its ecological succession, identifying the possible dynamic stages and the characteristics of the mature vegetation that can grow in the region. The Pioverna river, Lecco province (Italy), is one of the areas studied as part of the cooperation agreement. Phytosociological relevés were carried out along the river from April 2019 and assessment will continue until September 2019. The relevés were analysed using cluster analysis and CSR functional strategy and other ecological features of the species of each group were also evaluated (1 - 2 - 3). This abstract shows the preliminary results of the first surveys. Cluster analysis showed 3 groups: a) herbaceous vegetation (Figure 1a), b) vegetation dominated by Buddleja davidii Franch. (Fig. 1b), c) woody vegetation with Salix spp. and Robinia pseudoacacia L. (Fig. 1c). These are three stages in the ecological succession of this riparian ecosystem. Cluster a represents the first stage mainly composed by pioneer herbaceous species. The second (b) is a community dominated by one exotic and invasive plant (Buddleja davidii), which is widespread near Italian rivers. The last (c) represents vegetation closer to maturity where the coverage of Salix spp. has partially prevented the spread of Buddleja davidii. Overall strategy abilities indicate that group b has the highest value of competitive species, underlining that invasive plants can block community assembly through succession. The other two groups (a and c) have a higher proportion of stress- tolerant and ruderal species. For a complete description of the vegetation of the Pioverna river, the assessment will continue through summer 2019.