Interspecific variation in seed traits facilitates divergent pre-dispersal seed predation among five stone oak species

Abstract Background Seed traits, including size, nutrient content, mechanical and chemical defenses, are important factors influencing seed-animal interactions. Representing insect-seed antagonism, pre-dispersal seed predation (PSP) has a significant negative impact on plant reproductive success. However, empirical studies examining the influence of multiple seed traits on PSP are scarce. As dominant canopy tree species in evergreen forests of East Asia, Lithocarpus species serve as ideal models for investigating how seed traits affect PSP. Results We examined PSP in relation to fruit traits of five coexisting Lithocarpus species in a subtropical evergreen forest in Malipo, China. Our findings revealed significant interspecific variation in both PSP rates and seed traits. Mechanical defense was more effective than chemical defense in deterring PSP across the five species. Additionally, larger seeds were more susceptible to multi-larvae infestation. Among the infested fruits, weevils were the major pre-dispersal seed predators, outnumbering moths. However, PSP did not lead to substantial seed loss during the study year. Conclusion Our study highlights the effectiveness of mechanical defenses in reducing PSP. This study also provides empirical evidence that interspecific variation in seed traits drives PSP differentiation, offering new insights into biotic interactions and species coexistence within forest ecosystems.