Carabid beetle occurrence at the edges of oak and beech forests in NW Spain

Abstract

Abstract. We examined the occurrence of carabid beetles (Coleoptera, Carabidae) at the edges of oak (Quercus pyrenaica) and beech (Fagus sylvatica) forests in León, NW Spain. Pitfall traps were used to collect beetles from April to October 2002, and leaf litter cover and depth were measured. Traps were placed at three distances (0, 50 and 100 m) from the edges of eight forest patches. A total of 5436 carabids belonging to 43 species were collected. We found no statistically significant edge effect at the carabid assemblage level, i.e. the number of species and individuals was not higher at the edge compared to the forest interior. However, individual species were affected by distance from the edge. Five of the 14 species analysed responded predictably to the edge, three of them statistically significantly so. Four species did not respond in the predicted direction, two of them statistically significantly so. We found a considerable difference between forest types in terms of carabid assemblage composition and response to the edge. Oak forests were species richer and beech forests had a higher number of individuals. These differences were probably due to smallscale habitat heterogeneity in the oak forest patches, caused by man, and the homogeneous structure of beech forests. Leaf litter appeared to be one possible factor influencing the distribution of some species from the interior to the edge of forests.

Ground-dwelling arthropod communities present in three types of Cantabrian (NW Spain) heathland grazed by sheep or goats

“…Typical forest carabid species like C. macrocephalus or Pterostichus cantaber (Chaudoir, 1868) (Taboada et al, 2004), frequently found on heathlands (Cuesta et al, 2008), and most of the harvestmen, which survive best at high humidities (Bragagnolo et al, 2007), are clearly associated with the heather dominated areas. The high records of arthropods in the heather dominated areas might also be due to less trampling and soil compactation in these areas, and the lack of burning in the past might have favoured the presence of vegetation at a more advanced successional stage.…”

Time-consistent rearrangement of carabid beetle assemblages by an urbanisation gradient in Hungary

“…The proportion of both individuals and species belonging to forest specialist species increased as the cover by leaf litter cover, decaying wood, and herbs as well as prey availability increased. Leaf litter greatly influences the spatial occurrence pattern of carabids (Koivula et al, 1999;Magura et al, 2000Magura et al, , 2004Magura et al, , 2005Taboada et al, 2004). A high cover of leaf litter and decaying wood material indicate an undisturbed forest habitat which is preferred by forest specialists and provides shelter against predators, suitable sites for aestivation, hibernation, egg and larval development.…”

Traditional forest management: Do carabid beetles respond to human-created vegetation structures in an oak mosaic landscape?

“…Moreover, other typical forest types of the same mountainous area share a high number of carabid species with the Pyrenean oak forest: pine (31 of 50 collected species in common, Taboada et al, unpubl. ) and beech (13 of 19 species in common, Taboada et al, 2004). For example, Cryobius cantabricus and N. asturiensis, both forest specialist species, are endemic to the Cantabrian mountain range, but are found in all three forest types.…”