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.
Authors:T. Kadlec, M. Kotela, I. Novák, M. Konvička, and V. Jarošík
An assemblage of moth species at a suburb of Prague (50°5′11″N,14°18′06″E) was monitored by a highly efficient mercury light trap for 23 years (1967–1976, 1980–1992). Species caught were divided into guilds according to habitat specialisation, and analysed using species richness
, Shannon’s diversity
as the response variables, and the individual years of monitoring and effects of mean annual temperature and precipitation as the explanatory variables. Overall, 424 species were recorded: 25 early successional arable land species (43% of all caught individuals), 116 forest species feeding on trees and shrubs, 33 forest species feeding on woodland herbs and lichens, 92 forest-steppe species, 116 grassland species, 28 wetland species, and 14 non-specialized generalists. The diversity of habitat-specialised species responded mainly to land use changes, whereas the diversity of generalists reflected long-term meteorological trends. Species richness of specialists whose habitats in the vicinity of the trap have declined in extent decreased, the numbers of those whose habitats remained intact did not exhibit any particular trend, whereas the numbers of generalists increased, and their diversity positively responded to warming. It is concluded that the habitat specialists and generalists react to environmental changes differently. Non-specialised species appear more sensitive indicators of climate changes than habitat specialists because for the latter the indication of climate changes can be overlaid by changes in habitat use.