Consequences of plant population size and density for plant-pollinator interactions and plant performance

Summary 1  Habitat fragmentation and the resulting decline in the local abundance of plant species can affect biological interactions. We examined the effects of abundance on plant–pollinator interactions by observing the pollinator service and subsequent reproductive output of a mostly outbreeding, but self-compatible, plant, Lychnis viscaria, in experimental populations of different sizes (number of individuals) and densities (distance between individuals). 2  Bumblebees, the main pollinators of L. viscaria, preferred larger populations, but visitation rates were higher in sparser populations. Pollinators were attracted to the larger inflorescences in sparse populations, which were also m…