Responses of grassland specialist and generalist beetles to management and landscape complexity
We tested the influence of grazing intensity and effect of landscape complexity on grassland specialist and generalist beetles of three beetle families, i.e. Carabidae, Chrysomelidae, and Curculionidae, on extensively and intensively grazed cattle pastures in three regions of the Hungarian Great Plain. In every region we investigated seven pairs of grazed grasslands. On each field, samples were taken along two 95-m-long transects; one transect at the edge and the other one 50 m away from the edge in the grassland interior (altogether 84 transects). Carabids (Carabidae) were sampled using funnel traps for three 2-week sampling periods during spring and early summer. Leaf-beetles (Chrysomelidae) and weevils (Curculionidae) were surveyed by sweep netting in May and June 2003. Analysing the grazing intensity and landscape complexity effects on generalist and specialist beetles with linear mixed models, grazing effect was detected only on specialist leaf-beetle species richness with more species in the extensively grazed sites. Landscape complexity had contrasting effects on specialist and generalist species. Habitat generalists were more and negatively affected by increasing grassland coverage (reduced heterogeneity) than specialists. At species level analyses on four species out of 21, landscape effects were shown, which suggested that landscape composition might have strong effects on the species composition of the beetle assemblages. Our results suggest that conservation of biodiversity in agricultural systems (such as in managed Central European grasslands) requires a landscape perspective besides investigating management effects.
Document Type: Research Article
Affiliations: 1: Animal Ecology Research Group of the Hungarian Academy of Sciences and the Hungarian Natural History Museum, Ludovika tér 2, H-1083 Budapest, Hungary 2: Hungarian Natural History Museum, Ludovika tér 2, H-1083 Budapest, Hungary; and
Publication date: 2007-03-01