Conservation biogeography of large Mediterranean islands. Butterfly impoverishment, conservation priorities and inferences for an ecological "island paradigm"
Auteurs : Dapporto (Leonardo) et Dennis (Roger L.h.s.)
Année de publication : 2009
Publication : Ecography
Volume :
31
Fascicule : 1
Pagination : 169-179
Résumé :
pplyBrkRulesConservation biogeography is considered the Cinderella of biological/ conservation. Nevertheless biogeography provides the basis for/ establishing species distributions over space and time, therefore/ conservation priorities among areas and individual species. We/ demonstrate that there is no need to simplify analyses by using/ subsets of species (rare species, endemics) as surrogates. In doing/ so, we apply strict biogeographical techniques to determine butterfly/ impoverishment on three of the west Mediterranean's largest islands/ (Sardinia, Corsica and Sicily). The analyses performed on species,/ both collectively and individually, reveal that regional species/ richness in the Mediterranean zone can be largely predicted by/ latitude, altitude and latitudinal range (maximum minus minimum/ latitude), but that Sardinia and Corsica have clearly impoverished/ faunas. Logistic regression at individual species level demonstrates/ that several species, predicted to be present in these islands on the/ basis of their continental distributions, are actually absent. When/ compared with species that are present in these islands, such missing/ species are disclosed as having ecological traits which reduce their/ colonization capability. Probabilities of occurrence are calculated/ for each species on each island; they reflect the potential for each/ butterfly species to migrate to and colonise each island, and can be/ considered as a measure of conservation value. As such, species/ present on islands but having low immigration probabilities are/ predicted to represent isolated populations from the mainland that are/ unlikely to re-colonize the islands in the case of extinction. Island/ endemic species and races are shown to have lower occurrence/ probabilities compared to widespread species occurring on islands and/ illustrate the usefulness of occurrence probabilities for identifying/ isolated populations in need of conservation attention./SN··-·0906-7590