Consistent species roles and network structures in flower visitation and pollen load networks from a temperate pollination system.

Accurately characterizing plant-pollinator networks is essential for understanding mutualistic structure and ecological function. While plant-pollinator networks are usually constructed from flower visitation, the pollen load on pollinator body offers a complementary perspective by capturing the pollen transfer. However, whether the structural differences and species roles between visitation and pollen load networks are temporally consistent remains unclear. Here, we compared visitation and pollen load networks across five surveys in a warm-temperate forest in central China. For each survey, we constructed two types of networks and compared the network-, species-, and link-level properties. We found that pollen load networks exhibited more links, higher connectance and nestedness than visitation networks. At the species level, pollinators showed positive correlations between networks in degree, betweenness and closeness centrality, and specialization, suggesting more stable positions between network types. In contrast, plants exhibited larger variability. In the simulation comparisons, about half of the species differed significantly in degree. Differences in partner identity and motif roles were much smaller. Our study highlights the complementary value of visitation and pollen load for constructing plant-pollinator networks and underscores the importance of integrating behavioral and functional data to understand pollination dynamics.