其他知识库

Rodent-seed interactions are influenced strongly by seed traits. Seeds in natural systems rarely exist in isolation; they aggregate into spatially discrete patches with distinct trait distributions, where individual seed fate depends on both its own traits and those of its neighbors. While individual seed traits have been extensively studied, the role of patch-level trait distribution, particularly, relative variability (measured by the coefficient of variation, CV) and asymmetry in trait distribution (quantified by skewness) remains poorly understood. We conducted a controlled field experiment in a subtropical forest to examine how patch-level variation in seed size (quantified by CV and skewness) mediates seed predation and dispersal by rodents. Using two Fagaceae species (Lithocarpus pachyphyllus and Lithocarpus hancei), we established artificial seed patches (n = 41 per species) with standardized density and mean seed size but varying CV (0 to 0.68) and skewness (-0.74 to 2.75). Our results revealed that higher CV increased predation probability in L. pachyphyllus but reduced dispersal distance, while skewness showed no significant effects. Lithocarpus hancei exhibited no patch-level responses to trait distributions. However, both species showed context-dependent individual seed selection: the magnitudes and even the signs of effect of individual seed size on rodent foraging preference differed among patches. These findings demonstrate that intraspecific seed size variation mediates rodent-plant interactions through both patch-level and individual-scale processes, creating spatial mosaics of selection that may maintain seed size polymorphism. Our study highlights the importance of considering higher-order trait distribution statistics in seed dispersal ecology and provides mechanistic insights into how spatial variation in seed traits structures ecological interactions and potentially maintains trait diversity in plant populations.