Conservation of endemic insular plants: the genus Ribes L. (Grossulariaceae) in Sardinia.

Only two members of the genus Ribes L. (Grossulariaceae) occur in Sardinia, both endemic: R. sardoum and R. multiflorum subsp. sandalioticum. R. sardoum is categorized as Critically Endangered on the IUCN Red List and R. multiflorum subsp. sandalioticum is a rare species previously known from only a few localities. Both species grow only in mountainous areas. In 2006–2010 we carried out a field survey to verify the conservation status of R. sardoum and to estimate the number of individual plants, identify threats and assess the conservation status of R. multiflorum subsp. sandalioticum. R. sardoum is threatened by grazing, its small population, low seed viability and the activities of tourists, confirming its Critically Endangered status. We found R. multiflorum subsp. sandalioticum in 13 localities, three of which are new records, with the plants in scattered groups or singly, in three populations. The threats to R. multiflorum subsp. sandalioticum are overgrazing, the small populations, habitat fragmentation and the activities of tourists. We propose that R. multiflorum subsp. sandalioticum be categorized as Endangered on the IUCN Red List. Research activities and conservation measures for this genus on Sardinia have been proposed and some conservation actions have already commenced. [ABSTRACT FROM PUBLISHER]