Widening Niche Breadth: Investigating the Plasticity of Plant-Pollinator Interactions Open Access

Endres, Kelly (Spring 2019)

Permanent URL: https://etd.library.emory.edu/concern/etds/5425kb82t?locale=en


Plant-pollinator interactions are one of the most ecologically important mutualisms and are a vital part of most terrestrial ecosystems. Despite the importance of these interactions, we still lack understanding of how plant-pollinator interactions fluctuate with changes in resource availability. Fluidity in interactions is important to understand as swiftly changing climates and global pollinator declines threaten stability of ecosystems and maintenance of biodiversity. I investigated the plasticity of plant-pollinator interactions in response to drought conditions and resulting decreases in floral resources. I examined floral visitation to Ipomopsis aggregata in the Rocky Mountains of Colorado over the course of two drought years and three non-drought years. I analyzed changes in niche breadth and community composition, predicting broadened niche breadth and varied community composition in drought years compared to non-drought years. My results confirmed broadened niche breadth of I. aggregata in drought compared to non-drought years, and visitor category diversity and richness trended higher in drought years. Results also revealed some variation in visitor community composition. Overall, my findings highlight that pollination niches may exhibit considerable plasticity in response to disturbance and that plant-pollinator interactions can be dynamic. This plasticity may serve to stabilize plant and pollinator communities. However, there are also potential negative implications for plants in terms of lower quality pollination service and for pollinators based on fitness costs. 

Table of Contents

Introduction. 1

Materials and Methods. 4

Overview. 4

Study System. 5

Visitation Measurements. 6

Data Analysis. 7

Drought Determination. 7

Niche Breadth – Species Diversity. 8

Community Composition. 9

Results. 9

Overview. 10

Drought Determination. 10

Niche Breath – Species Diversity. 10

Community Composition. 11

Discussion. 11

References. 18

Tables. 26

Table 1. 26

Table 2. 27

Figures. 28

Figure 1. 28

Figure 2. 30

Appendix. 31

Appendix A. 31

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