Global meta-analysis shows an indispensable role of pollinator diversity in promoting fruit quality

Global pollinator decline threatens pollination services, biodiversity, and food security. However, large knowledge gaps remain regarding how pollinator diversity influences agricultural productivity, particularly in relation to multiple fruit quality traits. Here, we conducted a comprehensive global assessment of 79 studies with 451 effect sizes to investigate whether and how pollination services affect various fruit quality traits including organoleptic traits (e.g., size, shape, firmness) and nutritional traits (e.g., carbohydrates, macronutrients, micronutrients). Our analysis confirmed that animal pollination significantly enhances fruit quality by more than 30 %, a finding that is consistently observed across different ecological and agricultural systems, although such effects vary across different quality traits. For instance, organoleptic quality traits are highly dependent on the existence of animal pollination but are insensitive to high-quality pollination. Meanwhile, nutritional quality traits are promoted by increases in both pollinator species richness and visitation rate, although they are less affected by the presence or absence of animal pollination, suggesting a need for high-quality pollination. Interestingly, further analyses revealed that pollinator species richness promotes fruit micronutrients, while visitation rate enhances fruit macronutrients, indicating a complementary role of wild and managed pollinators in boosting fruit quality. Our results highlight the exclusive role of pollinator diversity in sustainable agriculture and therefore reinforce the rationale for wild pollinator conservation in the face of global pollinator decline.