The Context Dependence of Pollinator-Mediated Selection in Natural Populations

Pollinator-mediated selection to a large extent shapes angiosperm floral diversity, but clearly not in isolation. To understand how selection by pollinators interacts with other selective factors and depends on environmental context, studies that address multiple selective agents are necessary. Here, I illustrate how antagonistic interactions, community context, and resource availability may influence selection on floral traits. I discuss approaches to quantify the context dependence of pollinator-mediated selection, emphasizing experimental studies that manipulate pollination regime in combination with other putative selective factors. I also discuss how context dependence may differ between floral traits that affect pollinator attraction versus pollination efficiency. Finally, I suggest some areas where important progress can be made. A better understanding of the context dependence of pollinator-mediated selection is essential to predict when, where, and how environmental change will alter selection on floral traits.