Plant traits moderate pollen limitation of introduced and native plants: a phylogenetic meta-analysis of global scale

The role of pollination in the success of invasive plants needs to be understood because
invasives have substantial effects on species interactions and ecosystem functions. Previous
research has shown both that reproduction of invasive plants is often pollen limited and that
invasive plants can have high seed production, motivating the questions: How do invasive
populations maintain reproductive success in spite of pollen limitation? What species traits
moderate pollen limitation for invaders?
  We conducted a phylogenetic meta-analysis with 68 invasive, 50 introduced noninvasive
and 1931 native plant populations, across 1249 species.
  We found that invasive populations with generalist pollination or pollinator dependence
were less pollen limited than natives, but invasives and introduced noninvasives did not differ.
Invasive species produced 39 fewer ovules/flower and > 2509 more flowers per plant, compared
with their native relatives. While these traits were negatively correlated, consistent with
a tradeoff, this did not differ with invasion status.
  Invasive plants that produce many flowers and have floral generalisation are able to compensate
for or avoid pollen limitation, potentially helping to explain the invaders’ reproductive
successes.