Pollen Limitation of Plant Reproduction: Ecological and Evolutionary Causes and Consequences

Abstract

Determining whether seed production is pollen limited has been an area of intensive empirical study over the last two decades. Yet current evidence does not allow satisfactory assessment of the causes or consequences of pollen limitation. Here, we critically evaluate existing theory and issues concerning pollen limitation. Our main conclusion is that a change in approach is needed to determine whether pollen limitation reflects random fluctuations around a pollen-resource equilibrium, an adaptation to stochastic pollination environments, or a chronic syndrome caused by an environmental perturbation. We formalize and extend D. Haig and M. Westoby's conceptual model, and illustrate its use in guiding research on the evolutionary consequences of pollen limitation, i.e., whether plants evolve or have evolved to ameliorate pollen limitation. This synthesis also reveals that we are only beginning to understand when and how pollen limitation at the plant level translates into effects on plant population dynamics. We highlight the need for both theoretical and empirical approaches to gain a deeper understanding of the importance of life-history characters, Allee effects, and environmental perturbations in population declines mediated by pollen limitation. Lastly, our synthesis identifies a critical need for research on potential effects of pollen limitation at the community and ecosystem levels.

Pollinator and Herbivore Attraction to Cucurbita Floral Volatiles

“…Thus, the attraction of both pollinators and cucumber beetles is likely to have fitness consequences for native cucurbits and implications for crop yield in managed cucurbit systems. While a growing number of studies have demonstrated that floral display or reward can be costly due to the attraction of antagonists (Brody and Mitchell 1997;Adler and Bronstein 2004;Ashman et al 2004b;Strauss and Irwin 2004), the current study is one of few to address the role of scent in attracting pollinators compared to herbivores. Similar to our study, specific floral volatiles present in C. arvense scent attracted just pollinators, just herbivores, or both pollinators and herbivores (Theis 2006).…”

Impact of human disturbance on bee pollinator communities in savanna and agricultural sites in Burkina Faso, West Africa

“…When studying the impact of land‐use change and disturbance, it is of particular importance to understand whether organisms that perform important ecosystem services persist in human‐dominated ecosystems. Pollinators are one such group: Most of the world's flowering plants require animal pollinators (Ashman et al., 2004), and plant populations in human‐dominated ecosystems will only maintain genetic diversity if pollinators are present and can move freely through anthropogenic habitats (Keller & Waller, 2002). Bees are key providers of pollination services, which are vital for crop production and food security and the persistence of many wild plants (Klein et al., 2007; Ollerton, Winfree, & Tarrant, 2011).…”

Breeding system and pollination of Pleroma trichopodum DC. (Melastomataceae): a potential species for the restoration of Atlantic Forest in southern Brazil

“…Plant-pollinator interactions and the reproductive outcome of such mutualisms are central to plant population and community organization (Ashman et al 2004). For this reason, these topics have been intensively studied in a variety of contexts (Ayasse & Arroyo 2011).…”