Bee movement across heterogeneous tropical forests: multi‐paternal analyses reveal the importance of neighborhood composition for pollen dispersal

Animal pollination is critical for maintaining the reproduction and genetic diversity of many plant species, especially those in tropical ecosystems. Despite the threat to pollination posed by tropical deforestation, it remains an understudied process. In particular, little is known about these dynamics in multi‐paternal, successional plant species whose fruits can contain substantial genetic diversity. Given the importance of successional plants in reforestation, quantifying the factors that impact their reproduction is essential for understanding plant gene flow in the context of global change. In this study, we investigated pollen‐mediated gene flow at the multi‐paternal fruit level to quantify how tropical pollinators navigate and mediate gene flow in altered forests. Utilizing microsatellite genotyping and paternity analyses, we revealed that distinct plant neighborhood and individual factors drive pollen dispersal at the intra‐fruit scale. Variance in pollen dispersal distances was greater for neighborhoods with higher conspecific density, indicating that density dependent reproductive patterns play a role at this scale. Additionally, both the diversity and evenness of sires mediated by a single pollinator were affected by the size of the mother tree, that is, larger mothers received pollen from a less diverse, less even pool of sires per fruit. Pollinator body size was not found to be a significant driver of pollen dispersal, indicating that both small‐ and large‐bodied pollinators were equally important pollen dispersers at this scale. By exploring patterns of variation at the intra‐fruit level, we show that conspecific density and tree size significantly impact multi‐paternal pollen‐mediated gene flow, reinforcing the importance of investigating intraspecific, intra‐individual variance in plant reproduction.