Distribuzione e conservazione di Vertigo angustior e Vertigo muolinsiana (Mollusca, Gastropoda, Vertiginidae) in Toscana: stato delle conoscenze [Geographical distribution and conservation status of Vertigo angustior and Vertigo moulinsiana (Mollusca, Gastropoda, Vertiginidae) in Tuscany, Italy: State of the art]

The aim of the MONITO-RARE Project, a collaboration between the Tuscan Regional Government and the Universities of Florence, Pisa and Siena, was to gather, analyse and validate data on the status of species and habitats of conservation concern under Council Directive 92/43/ EEC (Habitats Directive). In the context of this project, the distribution and the status of the threatened land snail species Vertigo angustior and Vertigo moulinsiana was revised on the basis of data from available datasets (CKmap and RENATO) and from new field research. Assessment of the datasets CKmap and RENATO highlighted some critical aspects concerning the reliability: much of data is based on old reports, in some cases from alluvial debris of river basins that span much larger areas than the basic cartographic grid cells, and some records appear to be based on subfossil specimens. Finally the map coverage available from III Report of the Habitats Directive shows several inconsistencies with the available sets of data. The reports considered unreliable were therefore excluded and the datasets were integrated with new records mainly collected in the last decade. Analysis of this information indicates that Vertigo angustior has a scattered distribution in Tuscany, while Vertigo moulinsiana is extremely localized/rare. Both species, where present, occur at low densities and are generally linked to riparian vegetation of small streams. These marginal habitats are very circumscribed and are increasingly threatened by the heavy disturbance of reclamation agencies (Consorzi di Bonifica), commissioned by the Tuscan Regional Government for water course management. Thus the conservation status of both species in Tuscany cannot be considered favourable. © 2020 Societa Toscana di Scienze Naturali. All rights reserved.