Emma Dawson-Glass

Research technician | Technicienne de recherche
Determining the factors that limit species range distributions is fundamental to understanding patterns of diversity, particularly for plant species which often serve as the foundation of ecosystems. However, the extent to which biotic interactions, specifically mutualisms, influence species ranges is relatively understudied. Pollination is a mutualism that all plants rely on for sexual reproduction. Reduced quantity and quality of pollen at range edges, through reduced pollinator visitation or populations, can reduce reproductive output (by decreasing seed production), known as pollen limitation. By reducing seed production, pollen limitation could reduce reproduction and recruitment, preventing populations from persisting and thereby limiting range expansion. We use a meta-analysis of 484 studies and 586 plant species from a global pollen limitation database to answer the question: is pollen limitation stronger closer to plant range edges? Our initial results indicate that pollen limitation may not be a significant factor in limiting plant ranges at a macro scale, perhaps due to the complexity of interacting variables at range edges which may outweigh pollen limitation as a driver. However, further empirical studies of this question could further illuminate the influence of pollen limitation at range edges while considering these complexities.