Understorey phylogenetic diversity in thermophilous deciduous forests : overstorey species identity can matter more than species richness

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Contributo alla conoscenza della flora esotica dell'Arcipelago Toscano, Italia

Vengono segnalate nuove specie esotiche spontaneizzate in Arcipelago Toscano. Per ogni taxon sono riportati lo status di naturalizzazione, sia per ciascuna isola che per tutto l'Arcipelago, e i dati relativi alla distribuzione locale. Delle 40 specie elencate, 23 risultano nuove per il territorio dell'Arcipelago Toscano, tra le quali 10 nuove per l'intera Toscana; le restanti sono nuove per una o più isole

Patterns of change in α and β taxonomic and phylogenetic diversity in the secondary succession of semi-natural grasslands in the Northern Apennines

We studied the secondary succession in semi-natural grasslands (dry grasslands and hay meadows) located in the eastern side of the Tuscan Apennines (Tuscany, Central Italy). We compared these habitats, investigating: (i) the changes in species richness, composition and phylogenetic diversity during the succession; (ii) whether the trends in species loss and species turnover in taxonomic diversity matched those in phylogenetic diversity. We performed a stratified random sampling, in a full factorial design between habitat type and succession stage (60 sampled plots, 10 × 2 types of habitat × 3 stages of succession). We constructed a phylogenetic tree of the plant communities and compared the differences in taxonomic/phylogenetic α- and β-diversity between these two habitats and during their succession. We identified indicator species for each succession stage and habitat. Looking at α-diversity, both habitats displayed a decrease in species richness, with a random process of species selection in the earlier succession stages from the species regional pool. Nevertheless, in the latter stage of dry grasslands we recorded a shift towards phylogenetic overdispersion at the higher-level groups in the phylogenetic tree. In both habitats, while the richness decreased with succession stage, most species were replaced during the succession. However, the hay meadows were characterized by a higher rate of new species’ ingression whereas the dry grasslands became dominated with Juniperus communis. Accordingly, the two habitats showed similar features in phylogenetic β-diversity. The main component was true phylogenetic turnover, due to replacement of unique lineages along the succession. Nevertheless, in dry grasslands this trend is slightly higher than expected considering the major importance of difference in species richness of dry grasslands sites and this is due to the presence of a phylogenetically very distant species (J. communis)

Secondo contributo alla conoscenza della flora esotica dell'Arcipelago Toscano, Italia

Si presenta qui un secondo contributo per la realizzazione di una Checklist della flora esotica dell'Arcipelago Toscano. Per ogni taxon sono riportati lo status di naturalizzazione, sia per ciascuna isola che per l'intero Arcipelago, e i dati relativi alla distribuzione locale. Delle 31 specie elencate, 18 risultano nuove per il territorio dell'Arcipelago Toscano, tra le quali 4 nuove per l'intera Toscana; le restanti sono nuove per una o più isole