RESUMEN
AIM: Common species contribute more to species richness patterns (SRPs) than rare species in most studies. Our aim was to test this hypothesis using a novel model system, species living exclusively in subterranean habitats. They consist of mainly rare species (small ranges), only a few of them being common (large ranges), and challenge whether rare species are less important for the development of SRPs in this environment. We separately analyzed aquatic and terrestrial species. LOCATION: Western Balkans in southeastern Europe. METHODS: We assembled two datasets comprising 431 beetle and 145 amphipod species, representing the model groups of subterranean terrestrial and aquatic diversity, respectively. We assessed the importance of rare and common species using the stepwise reconstruction of SRPs and subsequent correlation analyses, corrected also for the cumulative information content of the subsets based on species prevalence. We applied generalized linear regression models to evaluate the importance of rare and common species in forming SRPs. Additionally, we analyzed the contribution of rare and common species in species-rich cells. RESULTS: Patterns of subterranean aquatic and terrestrial species richness overlapped only weakly, with aquatic species having larger ranges than terrestrial ones. Our analyses supported higher importance of common species for forming overall SRPs in both beetles and amphipods. However, in stepwise analysis corrected for information content, results were ambiguous. Common species presented a higher proportion of species than rare species in species-rich cells. MAIN CONCLUSION: We have shown that even in habitats with the domination of rare species, it is still common species that drive SRPs. This may be due to an even spatial distribution of rare species or spatial mismatch in hotspots of rare and common species. SRPs of aquatic and terrestrial subterranean organisms overlap very little, so the conservation approaches need to be habitat specific.
RESUMEN
Seven new species of the cavernicolous and anophthalmous genus Thaumastocephalus Poggi, Nonveiller, Colla, Pavicevic T. Rada, 2001 are described: T. bilandzijae sp. n., T. kirini sp. n., T. marsici sp. n., T. rujnicensis sp. n., T. slavkoi sp. n. and T. troglavi sp. n. from Croatia and T. dahnae sp. n. from Bosnia and Herzegovina. Aedeagi of all species are illustrated. A key to all species is provided. The records of all specimens of the genus treated here are given, and their distributions are discussed and shown on maps. The distribution of all genera of cavernicolous Pselaphinae in the Dinarides is discussed.