Project for a Sicilian Bryophyte Red List.

Abstract

Due to its location, Sicily has always represented an important biogeographic bridge between floras of 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 settlements which resulted in profound landscape changes in the past, but even at present human pressure continues to be very heavy. In spite of this, Sicily is part of one of the 10 most important hotspots in Mediterranean 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 vascular flora, very rich and likewise threatened. A first list of 182 endangered species of Sicily and small islands around it was compiled by Campisi & al. (2003: Intern. Sem. on Harmonization of Red Lists for threatened species, pp. 241-275), but a precise category of threat was not assigned to taxa. The establishment of a complete Red List is fundamental to bryophyte conservation in Sicily a fortiori because it is an Italian region with legislative and administrative autonomy in the field of environmental protection. The project, here presented, has just been started with regard to liverworts and hornworts. It takes into 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 threat categories, therefore, we opted for scaling the thresholds set of the Extent of Occurrence (EOO) and of the location number. Besides a red list the project provides for the realization of atlas of top 50 bryophyte taxa for which sheets with description, general and Sicilian distribution, ecology, EOO and AOO, the main threats and status in Sicily will be reported. Some examples of sheets of rare liverworts in the island are illustrated.