Are spiders reacting to local or landscape scale effects in Hungarian pastures?

Declines of West-European farmland biodiversity have been associated with intensive agricultural practices, Central and Eastern European grasslands still harbour a diverse and unique arthropod community. However, our understanding of the effects of farmland management both at local and landscape levels is rather limited there. A paired field approach was used to compare extensively (0.5 cows/ha) and intensively (>1 cows/ha) grazed pastures in 42 fields in three distinct biogeographic regions within Hungary. Spiders belonging to the hunting and web-building communities were sampled using funnel traps. We found no management effect either on richness and abundance or on species composition, which shows that both forms of grazing management at the intensity levels studied support valuable spider fauna. At the local scale plant and litter cover were the two most important variables that significantly affected the communities overall, meaning both the hunting and to some degree the web-building communities. No significant landscape effects were found in the analyses on spider richness and abundance, but community structure was affected by two landscape level factors (grassland patch density and grassland percentage). We suggest that to protect the valuable spider and other fauna of these regions, the recently launched national agri-environmental program should be further supported and enlarged to maintain and reintroduce the traditional grazing management on these semi-natural grasslands.