Environmental fallows as a new policy tool to safeguard farmland biodiversity in Finland

A novel agri-environment scheme for Environmental Fallows (EFs) was introduced in Finland to replace a former obligatory set-aside under the Common Agricultural Policy. It currently keeps fallow at nearly 7% of the agricultural land area and therefore may make a unique contribution to the enhancement of farmland biodiversity on the national scale. Farmers can chose from four types of EF fields (game, grassland, landscape, and meadow) or their combination as long as their total annual area falls within 5–15% of the field area. We studied the biodiversity value of EF fields in three regions across Finland (n = 229) based on survey data of vegetation in four fallow types. We compared EF plant communities to those of other non-cropped biotopes (margins and semi-natural grasslands) (n = 99). The meadow type sown with low competitive grasses and meadow species has proven to be the most species-rich EF type, approaching the diversity level of semi-natural meadows. Vegetation of the grassland type varied considerably ranging from swards similar to those of production grasslands to ones typical for semi-natural meadows. The vegetation composition of the game and landscape types of EF differed most from the other non-cropped biotopes, and other EFs. Plant species richness in the perennial fallows correlated positively with the parcel size (through increased within-field diversity) and age, and variation in the sward height. It was negatively related to the sward’s height and density, and the reported fertility level before EF establishment. Plant species richness in EFs was not related to the forest cover in the surrounding landscape. The scheme to a greater extent than the former set-aside contributed to both the amount and diversity of non-cropped vegetation on the landscape level. The long-term efficiency of the current scheme is likely to be compromised by its untargeted and unbinding nature.