Two groups of epigeic arthropods differ in colonising of piedmont quarries: the necessity of multi-taxa and life-history traits approaches in the monitoring studies

Abstract

It is increasingly understood that inventorying and monitoring biodiversity requires a multi-taxon approach and that comparing simple indices, such as species richness, should be accompanied by deeper analyses of species community composition and by comparisons of species life-history traits among taxa and habitats. Here, we document that two ecologically rather similar groups of epigeic predators, ground-dwelling spiders (Araneae) and ground beetles (Coleoptera: Carabidae), differ in patterns of stone quarry colonization. Such post-industrial barrens as abandoned quarries are increasingly appreciated as potential refuges for species that are becoming rare in modern landscapes. We compared species richness, community composition and species life-history traits of two epigeic invertebrates groups, in quarries and adjoining seminatural biotopes in a submountain region with granulite and limestone bedrock in SW Czech Republic. For both groups, quarries were species-poorer than seminatural sites, herbaceous biotopes were richer than scrubby and rocky biotopes, and no significant effects on species richness were revealed for substrate. Assemblages colonising quarries differed from those outside of quarries. They contained numerous regionally rarer species of rocks and scree in the case of spiders, but generalists of open landscapes prevailed among ground beetles. A survey limited to ground beetles, as well as to species richness analyses, would fail to detect a conservation potential of the quarries. Hence, a multi-taxa approach should be preferred, and species richness analyses should be assembled by insights onto community composition and species life-history traits in monitoring studies.