PARENT SESSION
Poster Session 38: Mutualism / Parasitism
Thursday, August 11, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal

Are non-native species more pollen limited than native species?

Harmon-Threatt, Alexandra^*,1, Knight, Tiffany ¹, ¹ Washington University in St. Louis, St. Louis, MO

ABSTRACT- The spread of exotic weeds has caused significant economical and ecological problems. The focus of much research is to predict which exotic plants will become pests, and to control existing pests. While there has been much work done on the role of plant enemies, the role of mutualists such as pollinators on seed production and spread of exotic species has been virtually ignored. Many non-native plants require pollinators for sexual reproduction, but occur without their co-evolved pollinators in their introduced range. Thus, we hypothesize that the reproduction of non-native plants will be more limited by pollinators than the reproduction of native plants. We compared native and exotic species in the same plant family. Using pairs of species with similar phylogenetic histories means that species will be similar in many aspects except for their native/exotic status. We experimentally determined the breeding system of these plants, observed pollinators, and tested for pollen limitation using a pollen supplementation experiment. We find that in outcrossing species, non-native plants were more pollen limited than there native counterparts. However, there is evidence that self-compatibility is more prevalent in non-native plants, making them less reliant on pollinators.

Key words: Invasive Species, Mutualism, Pollinators, Pollinator Limitation