Impacts of Non-native Plants on Plant-Pollinator Interactions

Abstract

There has been growing interest in the consequences of invasive non-native plants for the plant-pollinator mutualism, most likely because of its relevance for the maintenance of terrestrial biodiversity and food production. However, the development of this research field has been thematically uneven and the overall evidence inconclusive. Many studies have focused on how non-native plants interact with native plants via pollinator sharing, which have allowed meta-analytical syntheses, whereas several others have looked at how frequently non-native plants integrate into native plant-pollinator webs and how they affect network structure. However, relatively few studies have addressed the consequences of invasive plants for pollinators. Overall, the research approach in this area has been predominantly phenomenological rather than mechanistic, which has hindered our understanding of apparently contradictory evidence. One key characteristic of invasive non-native plants that seems to mediate negative effects on the pollination mutualism is the high relative abundance that they reach at late stages of invasion. This high dominance is apparently the main trigger of all the disruptive direct and indirect effects that are discussed in this chapter. Finally, we identify several intriguing questions on the ecological and evolutionary consequences of invasive plants for the plant-pollinator mutualism waiting to be answered.