Effects of abiotic factors on co-occurring Carabus (Coleoptera: Carabidae) species

Abstract

The members of the genus Carabus are among the most intensively studied beetle taxa, but many aspects of their autecology are still unexplored. We aimed to study the relationship between measured abiotic parameters and the spatial and temporal distribution of signature carabid species. Carabus assemblages were sampled by pitfalls at six sites belonging to two nearby locations, both forest habitats: in valley and in hill-top position. The sites showed variation in microclimatic and soil characteristics, to which the seven species caught showed specific spatial associations. Carabus scheidleri and C. coriaceus were ubiquitists, occurring at all sites. The habitat specialist C. violaceus germari indicated valley sites with high humidity, lower temperature, limy soil and higher pH, whereas the other specialists, C. nemoralis and C. convexus were strongly associated with the dry, warm, more acidic hill habitat. Remaining species were associated with specific sites and environmental features. The species also exhibited specific phenological patterns corresponding with their habitat preference. Hill habitat species exhibited peak activity density during the hottest summer period, whereas most other species had an activity depression during that period. The results suggest that although Carabus activity density patterns are species specific, they are largely affected by temperature both spatially and temporally.