Dissecting copepod diversity at different spatial scales in southern European groundwater

Abstract

Copepod diversity in southern European groundwater at different spatial scales was examined to evaluate the scale effect on α-, β- and γ-diversity across four regions. A total of 94 stygobiotic species were identified. permanova demonstrated that regional scale accounted for 47% of total variation for β-diversity. The aquifer scale was a significant component of β-diversity variation, whereas its effect on α-diversity variation was negligible. The local habitat scale accounted for 24% of total variation for α-diversity and 10% for β-diversity, respectively. Finally, mean α- and γ-diversity of aquifers were not linearly correlated, indicating a potential community saturation effect. The high level of endemism, low dispersal ability and high habitat specialization of stygobiotic copepods were invoked as major determinants of high species turnover among regions, aquifers and habitats. Scale effects on α-diversity were more controversial, suggesting that local assemblage saturation is scale-dependent and a reflection of local habitat structure and evolutionary processes.

Keywords:

• Copepoda
• groundwater
• stygobiont
• spatial scale
• southern Europe

Acknowledgements

The research project was granted by PASCALIS (Protocols for the ASsessment and Conservation of Aquatic Life In the Subsurface; contract no. EVK2-CT-2001-00121) and by the Italian Ministry of Education, Research and University, PRIN project “Phylogenetic and biogeographical assessment of endemic patterns of distribution in the Apennine Province (Italy): new tools for biodiversity assessment and conservation strategies”.