Ecosystem services in agriculture: How can annual plant mixes support pollinator populations?

Abstract Pollinator decline poses a significant threat to global biodiversity and agricultural productivity. This study investigated the effectiveness of specifically designed annual plant communities in enhancing pollinator activity across two contrasting climate zones: continental (Serbia) and temperate maritime (United Kingdom). Five annual plant community treatments (PCT) in Serbia and six annual PCT in the UK, designed to support either specific (e.g., support pollinator communities) or multiple ecosystem services and consisting of either wildflower mixes or underutilised crops, were established in replicated field trials in 2022 and 2023. Pollinator visitation rates were recorded for major insect groups, including bees, hoverflies and butterflies. The results showed that flowering date and PCT significantly influenced pollinator visitation rates, particularly in the UK (2022: p < 0.0001 and p = 0.0128 for flowering date and PCT, respectively; 2023: p < 0.0001 for both flowering date and PCT) and Serbia in 2023 ( p = 0.0013 and p = 0.0008 for flowering date and PCT, respectively). Across both regions, wildflower and multifunctional mixes consistently supported higher visitation than underutilised crop treatments. In the UK, pollinator visitation was nearly fourfold higher in 2023 than in 2022, while in Serbia, the highest visitation rates were consistently recorded in wildflower treatments. Pollinator activity showed clear seasonal patterns, peaking in mid‐summer (July in the UK, mid‐June in Serbia). Hoverflies and honey bees were the most abundant pollinator groups across both regions, although community composition varied between years and locations. Hoverflies were particularly abundant in the UK in 2023, while in Serbia, hoverflies, honey bees and wild bees were recorded more consistently. Plant attractiveness differed regionally: Phacelia tanacetifolia Benth and Fagopyrum esculentum Moench were most attractive to pollinators in Serbia, while Matricaria spp., Tripleurospermum inodorum L. and Amsinckia spp. were the most frequently visited species in the UK. Some underutilised crops, such as F. esculentum , could play a role in supporting pollinator populations. These findings suggest that annual plant communities can support pollinator activity and ecosystem service delivery in agroecosystems. Dedicated pollinator mixes consistently resulted in higher pollinator activity, although multifunctional communities yielded comparable results. Underutilised crops generally supported lower visitation; however, some species such as F. esculentum can provide pollinator resources.