Beyond Flower Abundance: Plant Attractiveness Explains Patterns of Pollinator Visits at the Community‐Level

Aims: Flower abundance is widely used to explain community-level patterns of pollinator visitation. However, studies often report contrasting relationships between flower abundance and pollinator visits, suggesting that additional factors operating at the community-level may modulate pollinator responses to flower abundance. In this study, we investigated whether incorporating measures of plant attractiveness at the community-level can help explain contrasting patterns of pollinator visits in temperate and Mediterranean regions. Location: Eastern Po Valley, north-eastern Italy (45°43′ N–45°01′ N, 11°00′ E–12°14′ E). Methods: We used 3 years of plant–pollinator interaction data collected in herbaceous semi-natural areas. A comprehensive dataset was first used to quantify the relative contribution of selected floral traits (flower size, colour and shape) to species-level visitation and to derive a species-level Plant Attractiveness Index (PAI). This index was then integrated into community-level analyses of two independent datasets to evaluate how accounting for plant attractiveness influences the relationship between flower abundance and pollinator visits. Results: We showed that when flower abundance was analysed without accounting for species-level attractiveness, the relationship with pollinator visits differed between years, showing either positive or hump-shaped patterns. In contrast, weighting flower abundance by species-level attractiveness revealed a consistent positive relationship. Conclusions: Our findings contribute to explaining why previous studies have reported linear, hump-shaped or negative flower–visitor relationships by showing that, once flower abundance is weighted by species-level attractiveness, pollinator visitation follows a consistently positive relationship.