Contemporary pollen flow as a multiscale process: evidence from the insect-pollinated herb, Pulsatilla vulgaris

1. Understanding the drivers and spatial scale of gene flow is essential for the management of species living in fragmented landscapes. In plants, contemporary pollen flow is typically modeled as a single spatial process, with pollen flow declining exponentially within a short distance of mother plants. However, growing evidence suggests that many species do not conform to this patterns, often showing an excess of long-distance dispersal events or sometimes even multimodality in dispersal kernels. This suggests that a single function might be insufficient to capture the true complexity of pollination, which in reality is often achieved by multiple pollinators that vary in their foraging ranges and interactions with the landscape. 2. We reconstructed realized pollen flow and assessed pollen immigration for seven populations of the insect-pollinated herb, Pulsatilla vulgaris. We quantified the effects of distance, floral resources, and landscape composition over multiple spatial scales, a...