Abstract
•We developed perennial, multifunctional flower strips with native plant species.•Flower strips were sown and established in apple orchards in six European countries.•Plant diversity was 43% higher as compared to the spontaneous orchard vegetation.•Agro-ecological highly relevant forbs that offer pollen and nectar were increased.•Mulching regime and climate affected these relevant forbs.
Orchards, as intensive cropping systems, often have low diversity of plant species, which limits the promotion of natural enemies for pest control. The implementation of agri-environmental schemes, such as flower strips, could enhance biological control. We developed perennial, multifunctional flower strips with native plant species. In the second and third year after sowing, plant diversity and ground cover between flower strips (FS) in the drive alleys and the spontaneous orchard vegetation in control plots (Cont) were compared in 19 experimental blocks of eight organic apple orchards in six European countries. On average 73.7% of the sown plant species were established and plant diversity of FS was on average 43% higher than in Cont. Multivariate analysis further revealed significant dissimilarities in the plant communities of the two treatments. Intensive mulching of flower strips also affected the plant community: species richness and ground cover by forbs and plants, which especially promote functional agrobiodiversity (FAB plants), decreased significantly. We show that perennial FS with native plants are a valuable approach to enrich plant diversity in orchards in different European countries. Limitations and recommendations for the implementation and management of FS in orchards are discussed.