The Potential of Newly Established Grassland Strips and Permanent Semi-Natural Grassland to Promote Common Carabids and Spiders on Arable Land

The implementation of grassland strips and maintenance of permanent semi-natural grassland are intended to promote insects on arable land to mitigate the consequences of habitat loss. While effects of grassland restoration on arable land in terms of improving overall insect diversity is well documented, knowledge on the effects on common arable species is deficient. We assessed the abundance of seven epigean carabids and five spiders in newly established grassland strips, adjacent permanent semi-natural grassland and arable crops nearby and further away from grassland strips over six years. Abundance was investigated using pitfall traps. Most carabids showed the highest abundance in arable crops and grassland strips, while permanent semi-natural grassland tended to be avoided. Epigean spiders showed similar patterns, however, some species were also associated with permanent semi-natural grassland. Pardosa palustris showed a distribution pattern with the highest individual numbers in OG and decreasing numbers toward the adjacent habitat’s grassland strips and cereals, most likely indicating spillover. The number of Brachinus crepitans/explodens was significantly higher in the first compared to the last sampling year in grassland strips due to changing habitat conditions with increasing habitat age. In conclusion, grassland strips provide an additional habitat for most of the studied species.