Abstract
Mediterranean islands have complex reptile assemblages, but little is known about the factors that determine their organization. In this study, the structure of assemblages of Squamata was evaluated based on their species richness and two measures of phylogenetic diversity (variability and clustering). I evaluated the composition of the assemblages comparing distinct biogeographic subregions within the Mediterranean: Adriatic, Aegean, Balearic, Corsica–Sardinia, Crete, Gulf of Gabés, Ionian Sea, Ligurian Sea, Malta, Sicily, and Tyrrhenian Sea. The effect of island environments and geographical isolation on the diversity metrics was assessed using generalized linear models. The analyses indicated that species richness was mostly influenced by island area and geographical isolation. Assemblages on smaller islands were poorer in species and phylogenetically dispersed, possibly as an effect of interspecific competition. The species composition of the assemblages was determined by similar environmental drivers within the biogeographic subregions, including island area, island elevation, geographical isolation, and aridity. In several subregions, significant patterns of phylogenetic attraction were found in species co‐occurrences, caused by the limits imposed by the island size on large predatory species.
Highlights
During the late Neogene, the Mediterranean basin was subjected to cyclical sea level fluctuations caused by climatic instability (Peirano et al, 2004)
The results of the generalized linear models (GLMs) analysis showed that the variables best explaining the variation in species richness were island area and mean annual temperature, which had positive influences, and mean sea depth in a 5 km radius and the distance to the continent or larger islands, which had negative influences (Table 1)
The analyses showed that the area of the islands and their geographical isolation determined the diversity of the Squamata assemblages, as expected
Summary
During the late Neogene, the Mediterranean basin was subjected to cyclical sea level fluctuations caused by climatic instability (Peirano et al, 2004). The fauna of the Mediterranean islands was later affected by the maritime trade that followed expansion of the Roman Era at approximately 2,300 years before present (BP). This led to extensive translocation of species from the continent to the islands in a process that has. Such interactions have been invoked to explain the assemblage composition on several Mediterranean islands (Grano, Cattaneo, & Cattaneo, 2013; Pérez-Mellado, Corti, & Lo Cascioa, 1997) For this reason, species co-occurrences determined by phylogenetic relationships and negative interspecific associations were expected to appear (Hypothesis 2)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
