Set-aside promotes insect and plant diversity in a Central European country

The area of non-cropped habitats has been decreasing in Europe largely due to land conversion into cropland and energy crops. In Hungary, special agri-environment schemes in Environmentally Sensitive Areas require the establishment of sown set-aside fields especially for endangered bird species. We tested if these set-aside fields are beneficial for plants and insects of agricultural landscapes. We compared the herbaceous flora, grasshopper (Orthoptera), bee (Apidae) and butterfly (Rhopalocera) fauna of five field types (1, 2 and 3 year-old set-aside, winter cereal fields and semi-natural grasslands). Species richness, abundance and species composition of insects were tested against field type and plant species richness. The wheat fields were the poorest habitats for all taxa. The species richness and abundance of the studied insects were usually higher in set-aside than in cereal fields with no significant difference between set-aside of different age. We found the highest number of orthopteran species and butterfly individuals in semi-natural grasslands. At community level, field type and plant species richness had a significant effect on orthopteran assemblages. Butterfly assemblages were significantly affected by field type. Bee assemblages were not significantly related to the above variables. We can conclude that set-aside fields provide important habitat patches for plants and insects, in some cases with similar value to semi-natural grasslands. Our results emphasise the importance of set-aside within the Hungarian agri-environment scheme. Establishment of set-aside management in other Central European countries will likely to be of a similar value as the Hungarian set-aside fields.

► More butterflies and orthopterans were in set-aside than in cereal fields.
► There was no difference in arthropods between set-aside of different age.
► Field type determined the assemblages of butterflies and orthopterans, but not bees.
► Species richness of herbaceous plants promoted orthopterans.