Project for a Sicilian Bryophyte Red List.

Due to its location, Sicily has always represented an important biogeographic bridge between florasof temperate and tropical climates as well as between those of the western and eastern Mediterranean.Its central position in the Mediterranean was also key factor of a millenary history of human settlementswhich resulted in profound landscape changes in the past, but even at present human pressurecontinues to be very heavy. In spite of this, Sicily is part of one of the 10 most important hotspots inMediterranean Basin, thanks to plant richness and endemism (Médail & Quézel 1999: Conserv. Biol.13(6): 1510-1513).The bryophyte flora, including ca. 600 taxa (almost half of Italian bryoflora), is, as well as vascularflora, very rich and likewise threatened. A first list of 182 endangered species of Sicily andsmall islands around it was compiled by Campisi & al. (2003: Intern. Sem. on Harmonization ofRed Lists for threatened species, pp. 241-275), but a precise category of threat was not assigned totaxa. The establishment of a complete Red List is fundamental to bryophyte conservation in Sicilya fortiori because it is an Italian region with legislative and administrative autonomy in the field ofenvironmental protection.The project, here presented, has just been started with regard to liverworts and hornworts. It takesinto account specific guidelines for bryophytes as well as the IUCN criteria. As to the latter, however,it was considered appropriate to adopt some changes to avoid an overestimate of endangered species,following a procedure similar to the one adopted by González-Mancebo & al. (2012: Biodivers.Conserv. 21: 3613-3636.) for the compilation of Red List of the Canary Islands. For assigning threatcategories, therefore, we opted for scaling the thresholds set of the Extent of Occurrence (EOO) and ofthe location number. Besides a red list the project provides for the realization of atlas of top 50bryophyte taxa for which sheets with description, general and Sicilian distribution, ecology, EOO andAOO, the main threats and status in Sicily will be reported. Some examples of sheets of rare liverwortsin the island are illustrated.